Breast Cancer

Think breast cancer survivors are unlikely to show up in your practice? You should think again.

At last official count, 2.5 million women in the United States had a history of breast cancer.¹ Most of them are now free of malignancy, but others are still grappling with the disease in some form or fashion.² All need continuing health care.

Roughly two thirds of women who have breast cancer have disease that is hormone-receptor–positive.^2,3 Recently updated guidelines from the American Society of Clinical Oncology (ASCO) recommend that adjuvant therapy for postmenopausal women who have hormone-positive breast cancer include an aromatase inhibitor (AI) (see a summary of these guidelines on page 36). That makes it likely that a good number of breast cancer survivors who visit your practice are taking one of these medications: anastrozole (Arimidex), letrozole (Femara), or exemestane (Aromasin). These drugs are antiestrogens, given to postmenopausal women to reduce the likelihood of disease recurrence and progression.

The antiestrogenic properties of these drugs are what make them lifesavers. But the same qualities can create a range of health issues, from increased risk of osteoporosis and fracture to vasomotor and joint symptoms. And although ObGyns are not the physicians who prescribe these drugs, you may be the provider one of these women consults about their side effects and related issues.

To find out the latest on the management of women who are taking one of these agents, we inserted ourselves into the busy schedule of Andrew M. Kaunitz, MD, who agreed to address some fundamental—and some not so basic—questions about the drugs. In this extended Q&A, Dr. Kaunitz touches on mechanism of action, benefits versus risks, common side effects, compliance with therapy, and the ill effects of early discontinuation.

Aromatase inhibitors are better than tamoxifen at reducing the risk of breast cancer recurrence in postmenopausal women who have hormone-receptor–positive disease. But, they increase the risk of osteoporosis and fracture and often cause arthralgias and other complaints that ObGyn practitioners may be called upon to manage.

OBG Management: What is the overall aim of adjuvant endocrine therapy in the setting of breast cancer?

Dr. Kaunitz: Endocrine therapy—specifically, use of an AI—prevents the stimulation of breast cancer cells by endogenous estrogen. In other words, aromatase inhibitors suppress the growth of cancer cells that have estrogen receptors. These drugs also inhibit aromatase near any breast tumor and reduce estrogen levels in breast tissue.

OBG Management: What is the mechanism of action of adjuvant endocrine therapy?

Dr. Kaunitz: In postmenopausal women, androgens are converted to estrogens via the aromatase enzyme, which is present in adipose tissue and other sites. By blocking this enzyme, AIs reduce endogenous estrogen levels by as much as 95%.⁴

OBG Management: How does that differ from the mechanism of action of tamoxifen, another drug used in breast cancer patients?

Dr. Kaunitz: Tamoxifen is a selective estrogen receptor modulator (SERM). It blocks estrogen in breast tissue selectively, by competitively binding to estrogen receptors.⁵ However, tamoxifen has estrogenic effects in the uterus, bone, and liver, as well as other tissues.

The efficacy of AIs in preventing breast cancer recurrence in the first 2 years after breast cancer surgery is higher than that of tamoxifen. And unlike tamoxifen, the AIs do not increase the risk of venous thromboembolism or cause endometrial disease.

OBG Management: What effects do aromatase inhibitors have in premenopausal women?

Dr. Kaunitz: These agents are not recommended for use in premenopausal women because, in that population, the lion’s share of estrogen production takes place in the ovary rather than in adipose tissue and muscle. If you were to administer an AI to a premenopausal woman, the reduced hypothalamic and pituitary estrogen feedback could lead to ovarian stimulation—which could increase ovarian steroid production.

OBG Management: What about women who become amenorrheic as a result of chemotherapy or other cancer treatment? Do most oncologists assume that they are postmenopausal and prescribe an aromatase inhibitor?

Dr. Kaunitz: Clinicians should not assume that chemotherapy-induced amenorrhea signals permanent cessation of ovarian function. It is common for ovarian function to return in this setting. Accordingly, follicle-stimulating hormone (FSH) and estradiol levels should be assessed before an AI is considered as adjuvant therapy. Some investigators have suggested that the use of an AI in women who have chemotherapy-induced amenorrhea may actually increase the likelihood that ovarian function will return.⁶

OBG Management: Do all AIs produce the same effects?

Dr. Kaunitz: The AIs used in women with breast cancer are third-generation drugs. These AIs are classified as steroidal (type 1; exemestane) or nonsteroidal (type 2; anastrozole, letrozole). Exemestane, a steroid derived from androstenedione, inhibits the aromatase enzyme irreversibly. The nonsteroidal AIs are reversible.

Although all three AIs have numerous similarities, there are other distinctions between them in pharmacokinetics, mechanism of action, and toxicity—so they are not completely interchangeable.⁷ However, from our perspective as ObGyns caring for breast cancer survivors, we can assume that all three AIs will have similar effects on skeletal health and produce similar side effects in postmenopausal women.

How much do we know about these drugs?

OBG Management: How long does a woman typically take an AI?

Dr. Kaunitz: At present, in women treated for early-stage, hormone-positive breast cancer, the optimal duration of treatment is unknown. Most oncologists prescribe an AI for 5 years, the length of treatment in a prominent trial of the drugs.⁸

OBG Management: Is that duration likely to increase as more data come in?

Dr. Kaunitz: The optimal duration of adjuvant AI therapy will be determined by the findings of long-term clinical trials. The National Surgical Adjuvant Breast and Bowel Project B-42 trial may provide new insights into optimal duration of AI treatment after initial tamoxifen therapy.⁹

OBG Management: How thoroughly have AIs been studied in regard to their use in breast cancer survivors and women who have early-stage disease? How would you characterize the quantity and quality of data that we have so far?

Dr. Kaunitz: AIs have been extensively studied. The most important clinical trials of AIs in this setting, including the Anastrozole, Tamoxifen Alone or in Combination (ATAC) trial (over 6,000 participants, median follow-up of 100 months) and the Breast International Group (BIG) trial (almost 5,000 participants, median follow-up of 76 months) have been detailed in the recent ASCO report.¹⁰ These two large landmark trials, in particular, formed the basis for ASCO’s recommendations to routinely incorporate AIs into the therapy of postmenopausal women who have hormone-receptor–positive breast cancer.

OBG Management: In treating breast cancer, what other applications are AIs used for?

Dr. Kaunitz: AIs appear to be slightly more effective than tamoxifen in treating postmenopausal women who have metastatic breast cancer.¹¹

They are approved as first-line therapy for breast cancer in:

• postmenopausal women who have hormone-receptor–positive disease
• postmenopausal women who have locally advanced disease when the hormone receptor is unknown
• postmenopausal women who have metastatic disease.

In addition, they are approved as second-line treatment of advanced breast cancer in postmenopausal women who have disease progression following tamoxifen therapy.¹²

How effective is AI therapy?

OBG Management: What do we know about the efficacy of these drugs?

Dr. Kaunitz: Most of the studies that have explored efficacy compare an AI with tamoxifen rather than with placebo. In the ATAC trial, after a median follow-up of 33 months, women who were taking anastrozole for early-stage breast cancer had longer disease-free survival and time to recurrence and a lower incidence of contralateral breast cancer than did women taking tamoxifen.⁸

After 4 years of follow-up in the ATAC trial, women taking anastrozole continued to have more favorable disease-free survival (86.9% vs 84.5% for anastrozole and tamoxifen, respectively; hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.76–0.99; P =.03).¹³ They also had a more favorable time to recurrence than did women taking tamoxifen (HR, 0.83; 95% CI, 0.71–0.96; P =.015). And women taking anastrozole had a lower incidence of contralateral breast cancer, as well, although this different did not achieve statistical significance (HR, 0.62; 95% CI, 0.38–1.02; P =.062).¹³

In the BIG study, women taking letrozole had a 5-year disease-free survival estimate of 84.0%, compared with 81.4% for women taking tamoxifen.¹⁴ In addition, women taking letrozole were significantly less likely than those taking tamoxifen to experience an event that ended a period of disease-free survival (HR, 0.81; 95% CI, 0.70–0.93; P =.003), especially the event of distant recurrence (HR, 0.73; 95% CI, 0.60–0.88; P =.001).¹⁴

And a phase-3 study of exemestane versus tamoxifen in women who had metastatic breast cancer found that the AI produced a superior response rate (46% vs 31% for exemestane and tamoxifen, respectively; odds ratio [OR], 1.85; 95% CI, 1.21–2.82; P =.005). In addition, median progression-free survival was greater with exemestane (9.9 months; 95% CI, 8.7–11.8 months) than with tamoxifen (5.8 months; 95% CI, 5.3–8.1 months). However, there was no difference between arms in progression-free survival or overall survival.

How well tolerated are AIs?

OBG Management: What adverse effects are associated with AIs?

Dr. Kaunitz: Although AIs, overall, are safe medications, their use is associated with a number of adverse events. The most prominent side effects include arthralgias and hot flushes, while the most serious health impact appears to be a decrease in bone mineral density (BMD).

However, the drugs are generally perceived as being easier to tolerate than tamoxifen. That’s because endometrial cancer, vaginal bleeding and discharge, cerebrovascular events, venous thromboembolic events, and hot flushes all are less common among women taking an AI than among those taking tamoxifen.^8,13

For overweight women, who face an elevated baseline risk of thromboembolism, the availability of AIs represents a major advantage over tamoxifen. Similarly, AIs offer advantages over tamoxifen for women who have an intact uterus. In addition, postmenopausal women who are taking a selective serotonin reuptake inhibitor (SSRI) such as paroxetine should take an AI rather than tamoxifen, because the concomitant use of SSRIs attenuates the efficacy of tamoxifen.¹⁵

What can be done about the most prominent risks?

OBG Management: Let’s focus on what’s probably the best-known adverse effect of AIs—the heightened risk of osteoporosis and fracture. How significant is this effect?

Dr. Kaunitz: Because use of an AI is associated with a profound reduction in endogenous estrogen levels, it also decreases BMD and can lead to osteoporotic fractures. All major phase-3 trials of adjuvant use of AIs in women who have early breast cancer found an increased risk of fracture, with no significant differences between AIs.¹⁶

Fortunately, bisphosphonate therapy (oral or intravenous) has been found to reduce bone loss associated with AI therapy.^17,18

Assessing baseline BMD is important as women initiate AI therapy. Although no consensus exists regarding follow-up BMD assessment in the setting of AI use, an interval of 2 years is prudent, with the follow-up study preferably performed at the same imaging center and by the same technician as the first. If baseline osteoporosis is observed at the lumbar spine or hip, bisphosphonate therapy is appropriate. If a woman taking an AI has low bone mass (osteopenia) but not osteoporosis, bisphosphonate therapy should be considered if any of the following risk factors are present:

• advanced age
• history of fracture
• glucocorticoid therapy
• parental history of hip fracture
• low body weight
• current smoking status
• excess alcohol consumption
• rheumatoid arthritis
• known risk factors for secondary osteoporosis.¹⁹

In breast cancer survivors initiating or continuing AI therapy, it is also appropriate to check a serum vitamin D level and ensure that intake of this nutrient is adequate.

Bisphosphonates may offer oncologic benefits, as well; preliminary evidence suggests that the drugs may prevent recurrence of the cancer and prolong survival.²⁰

OBG Management: What can an ObGyn offer to a woman who complains of significant AI-related arthralgia?

Dr. Kaunitz: Bone and joint symptoms, including aches, pain, and stiffness that is bilateral and not associated with other evidence of rheumatologic disorders, are among the most common side effects of AI therapy. On the plus side of the equation, these symptoms are more likely to be mild to moderate than severe. On the negative side, no specific treatment has been found to be effective in relieving these symptoms, which usually resolve within 2 months or so after discontinuing AI therapy.¹⁰

OBG Management: Do AIs have a negative impact on cardiovascular health?

Dr. Kaunitz: Unlike tamoxifen, AIs do not increase the risk of thromboembolic disease. Although the use of an AI may modestly increase the risk of ischemic cardiovascular disease (and lipid changes), compared with tamoxifen, AIs do not appear to increase cardiovascular risk compared with placebo.^21,22

OBG Management: Do the antiestrogenic effects of AIs have a significant impact on vaginal health and sexual desire?

Dr. Kaunitz: A review of published reports did not find that the use of AIs has a predictable impact on vaginal dryness or sexual desire.¹⁰ However, symptomatic genital atrophy is common in postmenopausal breast cancer survivors, whether or not they use adjuvant therapy.

Although the FDA considers the use of any estrogen (systemic or vaginal) following a diagnosis of breast cancer to be contraindicated, some breast cancer survivors who have symptomatic genital atrophy express an interest in the use of vaginal estrogen. Use of 25-μg estradiol tablets (Vagifem) is associated with a short-term increase in serum estradiol levels.²³ This finding has reinforced caution among medical oncologists about the safety of vaginal estrogen in breast cancer survivors. (The 25-μg tablets are no longer marketed.) The lowest dosage of vaginal estrogen available for the treatment of genital atrophy is found in 10-μg estradiol tablets (Vagifem) and the estradiol (2-mg) 3-month vaginal ring (Estring). Nonetheless, in the absence of data, oncologists will likely continue to be concerned that even the lowest dosage of vaginal estrogen could attenuate the favorable impact of AIs on breast cancer. Accordingly, use of vaginal lubricants and moisturizers are the mainstay strategy for symptomatic genital atrophy.

OBG Management: What about the ubiquitous hot flush? Vasomotor symptoms may be more common in women who take tamoxifen, but women on AIs are also bothered by flushes. What are the alternatives to estrogen therapy?

Dr. Kaunitz: Both nonprescription and prescription alternatives are available. Nonprescription options include soy extract and red clover isoflavones, black cohosh, and Chinese herbs. However, none of these over-the-counter approaches has been found to be more effective than placebo in the treatment of menopausal hot flushes.^24-26

As for prescription nonhormonal options, ObGyns should recognize that all such treatments are off-label and that none attain the efficacy of hormone therapy in the treatment of vasomotor symptoms. The best-studied and most effective medications include gabapentin, SSRIs (especially paroxetine), and serotonin-norepinephrine reuptake inhibitors (venlafaxine and desvenlafaxine).^24,27

OBG Management: Is there any evidence that AIs impair cognitive function in postmenopausal women?

Dr. Kaunitz: Because estrogen is important for cognition, one might anticipate that the profound reduction in background estrogen associated with AI use would impair cognition. Fortunately, the evidence to date is reassuring. Substudies of the BIG trial and the Tamoxifen and Exemestane Adjuvant Multinational Trial indicate that, compared with tamoxifen (which is associated with declines in cognitive function in postmenopausal women), letrozole and exemestane do not diminish cognitive function.^28,29

OBG Management: Overall, what is the typical impact of an AI on a woman’s quality of life?

Dr. Kaunitz: Most women do very well on an AI, finding it easier to tolerate than tamoxifen, as we have discussed. However, a significant minority of women is seriously bothered by the adverse effects, with arthralgias usually leading the pack of complaints.^30,31

OBG Management: Do some women discontinue adjuvant endocrine therapy because of adverse effects?

Dr. Kaunitz: Regrettably, the answer is “Yes.” A recent study from Kaiser Permanente of northern California found that roughly 50% of women who are prescribed adjuvant endocrine therapy with tamoxifen or an AI discontinue the drug early.³²

OBG Management: What can an ObGyn do to encourage compliance with and completion of AI therapy?

Dr. Kaunitz: First, it is critical that patients understand that AIs are lifesaving drugs. As a recent paper points out, early discontinuation or noncompliance with AI therapy is associated with higher mortality.³³

Clinicians should also help breast cancer patients understand what common side effects to anticipate with these medications.

Finally, clinicians who understand the financial toll a breast cancer diagnosis and treatment can take are better positioned to help women overcome challenges that may interfere with long-term compliance with AI therapy.

OBG Management: Do you expect the use of AIs in breast cancer survivors to become more commonplace?

Dr. Kaunitz: Given how common breast cancer is, and given the new ASCO guidelines and the extensive literature upon which they are based, ObGyns will be seeing more women using AIs. Although we are not the physicians who prescribe AIs, we need to remain up to date on their benefits and side effects. This important class of drugs is positioned to improve outcomes for postmenopausal women with breast cancer.

We want to hear from you! Tell us what you think.

Think breast cancer survivors are unlikely to show up in your practice? You should think again.

At last official count, 2.5 million women in the United States had a history of breast cancer.¹ Most of them are now free of malignancy, but others are still grappling with the disease in some form or fashion.² All need continuing health care.

Roughly two thirds of women who have breast cancer have disease that is hormone-receptor–positive.^2,3 Recently updated guidelines from the American Society of Clinical Oncology (ASCO) recommend that adjuvant therapy for postmenopausal women who have hormone-positive breast cancer include an aromatase inhibitor (AI) (see a summary of these guidelines on page 36). That makes it likely that a good number of breast cancer survivors who visit your practice are taking one of these medications: anastrozole (Arimidex), letrozole (Femara), or exemestane (Aromasin). These drugs are antiestrogens, given to postmenopausal women to reduce the likelihood of disease recurrence and progression.

The antiestrogenic properties of these drugs are what make them lifesavers. But the same qualities can create a range of health issues, from increased risk of osteoporosis and fracture to vasomotor and joint symptoms. And although ObGyns are not the physicians who prescribe these drugs, you may be the provider one of these women consults about their side effects and related issues.

To find out the latest on the management of women who are taking one of these agents, we inserted ourselves into the busy schedule of Andrew M. Kaunitz, MD, who agreed to address some fundamental—and some not so basic—questions about the drugs. In this extended Q&A, Dr. Kaunitz touches on mechanism of action, benefits versus risks, common side effects, compliance with therapy, and the ill effects of early discontinuation.

Aromatase inhibitors are better than tamoxifen at reducing the risk of breast cancer recurrence in postmenopausal women who have hormone-receptor–positive disease. But, they increase the risk of osteoporosis and fracture and often cause arthralgias and other complaints that ObGyn practitioners may be called upon to manage.

OBG Management: What is the overall aim of adjuvant endocrine therapy in the setting of breast cancer?

Dr. Kaunitz: Endocrine therapy—specifically, use of an AI—prevents the stimulation of breast cancer cells by endogenous estrogen. In other words, aromatase inhibitors suppress the growth of cancer cells that have estrogen receptors. These drugs also inhibit aromatase near any breast tumor and reduce estrogen levels in breast tissue.

OBG Management: What is the mechanism of action of adjuvant endocrine therapy?

Dr. Kaunitz: In postmenopausal women, androgens are converted to estrogens via the aromatase enzyme, which is present in adipose tissue and other sites. By blocking this enzyme, AIs reduce endogenous estrogen levels by as much as 95%.⁴

OBG Management: How does that differ from the mechanism of action of tamoxifen, another drug used in breast cancer patients?

Dr. Kaunitz: Tamoxifen is a selective estrogen receptor modulator (SERM). It blocks estrogen in breast tissue selectively, by competitively binding to estrogen receptors.⁵ However, tamoxifen has estrogenic effects in the uterus, bone, and liver, as well as other tissues.

The efficacy of AIs in preventing breast cancer recurrence in the first 2 years after breast cancer surgery is higher than that of tamoxifen. And unlike tamoxifen, the AIs do not increase the risk of venous thromboembolism or cause endometrial disease.

OBG Management: What effects do aromatase inhibitors have in premenopausal women?

Dr. Kaunitz: These agents are not recommended for use in premenopausal women because, in that population, the lion’s share of estrogen production takes place in the ovary rather than in adipose tissue and muscle. If you were to administer an AI to a premenopausal woman, the reduced hypothalamic and pituitary estrogen feedback could lead to ovarian stimulation—which could increase ovarian steroid production.

OBG Management: What about women who become amenorrheic as a result of chemotherapy or other cancer treatment? Do most oncologists assume that they are postmenopausal and prescribe an aromatase inhibitor?

Dr. Kaunitz: Clinicians should not assume that chemotherapy-induced amenorrhea signals permanent cessation of ovarian function. It is common for ovarian function to return in this setting. Accordingly, follicle-stimulating hormone (FSH) and estradiol levels should be assessed before an AI is considered as adjuvant therapy. Some investigators have suggested that the use of an AI in women who have chemotherapy-induced amenorrhea may actually increase the likelihood that ovarian function will return.⁶

OBG Management: Do all AIs produce the same effects?

Dr. Kaunitz: The AIs used in women with breast cancer are third-generation drugs. These AIs are classified as steroidal (type 1; exemestane) or nonsteroidal (type 2; anastrozole, letrozole). Exemestane, a steroid derived from androstenedione, inhibits the aromatase enzyme irreversibly. The nonsteroidal AIs are reversible.

Although all three AIs have numerous similarities, there are other distinctions between them in pharmacokinetics, mechanism of action, and toxicity—so they are not completely interchangeable.⁷ However, from our perspective as ObGyns caring for breast cancer survivors, we can assume that all three AIs will have similar effects on skeletal health and produce similar side effects in postmenopausal women.

How much do we know about these drugs?

OBG Management: How long does a woman typically take an AI?

Dr. Kaunitz: At present, in women treated for early-stage, hormone-positive breast cancer, the optimal duration of treatment is unknown. Most oncologists prescribe an AI for 5 years, the length of treatment in a prominent trial of the drugs.⁸

OBG Management: Is that duration likely to increase as more data come in?

Dr. Kaunitz: The optimal duration of adjuvant AI therapy will be determined by the findings of long-term clinical trials. The National Surgical Adjuvant Breast and Bowel Project B-42 trial may provide new insights into optimal duration of AI treatment after initial tamoxifen therapy.⁹

OBG Management: How thoroughly have AIs been studied in regard to their use in breast cancer survivors and women who have early-stage disease? How would you characterize the quantity and quality of data that we have so far?

Dr. Kaunitz: AIs have been extensively studied. The most important clinical trials of AIs in this setting, including the Anastrozole, Tamoxifen Alone or in Combination (ATAC) trial (over 6,000 participants, median follow-up of 100 months) and the Breast International Group (BIG) trial (almost 5,000 participants, median follow-up of 76 months) have been detailed in the recent ASCO report.¹⁰ These two large landmark trials, in particular, formed the basis for ASCO’s recommendations to routinely incorporate AIs into the therapy of postmenopausal women who have hormone-receptor–positive breast cancer.

OBG Management: In treating breast cancer, what other applications are AIs used for?

Dr. Kaunitz: AIs appear to be slightly more effective than tamoxifen in treating postmenopausal women who have metastatic breast cancer.¹¹

They are approved as first-line therapy for breast cancer in:

• postmenopausal women who have hormone-receptor–positive disease
• postmenopausal women who have locally advanced disease when the hormone receptor is unknown
• postmenopausal women who have metastatic disease.

In addition, they are approved as second-line treatment of advanced breast cancer in postmenopausal women who have disease progression following tamoxifen therapy.¹²

How effective is AI therapy?

OBG Management: What do we know about the efficacy of these drugs?

Dr. Kaunitz: Most of the studies that have explored efficacy compare an AI with tamoxifen rather than with placebo. In the ATAC trial, after a median follow-up of 33 months, women who were taking anastrozole for early-stage breast cancer had longer disease-free survival and time to recurrence and a lower incidence of contralateral breast cancer than did women taking tamoxifen.⁸

After 4 years of follow-up in the ATAC trial, women taking anastrozole continued to have more favorable disease-free survival (86.9% vs 84.5% for anastrozole and tamoxifen, respectively; hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.76–0.99; P =.03).¹³ They also had a more favorable time to recurrence than did women taking tamoxifen (HR, 0.83; 95% CI, 0.71–0.96; P =.015). And women taking anastrozole had a lower incidence of contralateral breast cancer, as well, although this different did not achieve statistical significance (HR, 0.62; 95% CI, 0.38–1.02; P =.062).¹³

In the BIG study, women taking letrozole had a 5-year disease-free survival estimate of 84.0%, compared with 81.4% for women taking tamoxifen.¹⁴ In addition, women taking letrozole were significantly less likely than those taking tamoxifen to experience an event that ended a period of disease-free survival (HR, 0.81; 95% CI, 0.70–0.93; P =.003), especially the event of distant recurrence (HR, 0.73; 95% CI, 0.60–0.88; P =.001).¹⁴

And a phase-3 study of exemestane versus tamoxifen in women who had metastatic breast cancer found that the AI produced a superior response rate (46% vs 31% for exemestane and tamoxifen, respectively; odds ratio [OR], 1.85; 95% CI, 1.21–2.82; P =.005). In addition, median progression-free survival was greater with exemestane (9.9 months; 95% CI, 8.7–11.8 months) than with tamoxifen (5.8 months; 95% CI, 5.3–8.1 months). However, there was no difference between arms in progression-free survival or overall survival.

How well tolerated are AIs?

OBG Management: What adverse effects are associated with AIs?

Dr. Kaunitz: Although AIs, overall, are safe medications, their use is associated with a number of adverse events. The most prominent side effects include arthralgias and hot flushes, while the most serious health impact appears to be a decrease in bone mineral density (BMD).

However, the drugs are generally perceived as being easier to tolerate than tamoxifen. That’s because endometrial cancer, vaginal bleeding and discharge, cerebrovascular events, venous thromboembolic events, and hot flushes all are less common among women taking an AI than among those taking tamoxifen.^8,13

For overweight women, who face an elevated baseline risk of thromboembolism, the availability of AIs represents a major advantage over tamoxifen. Similarly, AIs offer advantages over tamoxifen for women who have an intact uterus. In addition, postmenopausal women who are taking a selective serotonin reuptake inhibitor (SSRI) such as paroxetine should take an AI rather than tamoxifen, because the concomitant use of SSRIs attenuates the efficacy of tamoxifen.¹⁵

What can be done about the most prominent risks?

OBG Management: Let’s focus on what’s probably the best-known adverse effect of AIs—the heightened risk of osteoporosis and fracture. How significant is this effect?

Dr. Kaunitz: Because use of an AI is associated with a profound reduction in endogenous estrogen levels, it also decreases BMD and can lead to osteoporotic fractures. All major phase-3 trials of adjuvant use of AIs in women who have early breast cancer found an increased risk of fracture, with no significant differences between AIs.¹⁶

Fortunately, bisphosphonate therapy (oral or intravenous) has been found to reduce bone loss associated with AI therapy.^17,18

Assessing baseline BMD is important as women initiate AI therapy. Although no consensus exists regarding follow-up BMD assessment in the setting of AI use, an interval of 2 years is prudent, with the follow-up study preferably performed at the same imaging center and by the same technician as the first. If baseline osteoporosis is observed at the lumbar spine or hip, bisphosphonate therapy is appropriate. If a woman taking an AI has low bone mass (osteopenia) but not osteoporosis, bisphosphonate therapy should be considered if any of the following risk factors are present:

• advanced age
• history of fracture
• glucocorticoid therapy
• parental history of hip fracture
• low body weight
• current smoking status
• excess alcohol consumption
• rheumatoid arthritis
• known risk factors for secondary osteoporosis.¹⁹

In breast cancer survivors initiating or continuing AI therapy, it is also appropriate to check a serum vitamin D level and ensure that intake of this nutrient is adequate.

Bisphosphonates may offer oncologic benefits, as well; preliminary evidence suggests that the drugs may prevent recurrence of the cancer and prolong survival.²⁰

OBG Management: What can an ObGyn offer to a woman who complains of significant AI-related arthralgia?

Dr. Kaunitz: Bone and joint symptoms, including aches, pain, and stiffness that is bilateral and not associated with other evidence of rheumatologic disorders, are among the most common side effects of AI therapy. On the plus side of the equation, these symptoms are more likely to be mild to moderate than severe. On the negative side, no specific treatment has been found to be effective in relieving these symptoms, which usually resolve within 2 months or so after discontinuing AI therapy.¹⁰

OBG Management: Do AIs have a negative impact on cardiovascular health?

Dr. Kaunitz: Unlike tamoxifen, AIs do not increase the risk of thromboembolic disease. Although the use of an AI may modestly increase the risk of ischemic cardiovascular disease (and lipid changes), compared with tamoxifen, AIs do not appear to increase cardiovascular risk compared with placebo.^21,22

OBG Management: Do the antiestrogenic effects of AIs have a significant impact on vaginal health and sexual desire?

Dr. Kaunitz: A review of published reports did not find that the use of AIs has a predictable impact on vaginal dryness or sexual desire.¹⁰ However, symptomatic genital atrophy is common in postmenopausal breast cancer survivors, whether or not they use adjuvant therapy.

Although the FDA considers the use of any estrogen (systemic or vaginal) following a diagnosis of breast cancer to be contraindicated, some breast cancer survivors who have symptomatic genital atrophy express an interest in the use of vaginal estrogen. Use of 25-μg estradiol tablets (Vagifem) is associated with a short-term increase in serum estradiol levels.²³ This finding has reinforced caution among medical oncologists about the safety of vaginal estrogen in breast cancer survivors. (The 25-μg tablets are no longer marketed.) The lowest dosage of vaginal estrogen available for the treatment of genital atrophy is found in 10-μg estradiol tablets (Vagifem) and the estradiol (2-mg) 3-month vaginal ring (Estring). Nonetheless, in the absence of data, oncologists will likely continue to be concerned that even the lowest dosage of vaginal estrogen could attenuate the favorable impact of AIs on breast cancer. Accordingly, use of vaginal lubricants and moisturizers are the mainstay strategy for symptomatic genital atrophy.

OBG Management: What about the ubiquitous hot flush? Vasomotor symptoms may be more common in women who take tamoxifen, but women on AIs are also bothered by flushes. What are the alternatives to estrogen therapy?

Dr. Kaunitz: Both nonprescription and prescription alternatives are available. Nonprescription options include soy extract and red clover isoflavones, black cohosh, and Chinese herbs. However, none of these over-the-counter approaches has been found to be more effective than placebo in the treatment of menopausal hot flushes.^24-26

As for prescription nonhormonal options, ObGyns should recognize that all such treatments are off-label and that none attain the efficacy of hormone therapy in the treatment of vasomotor symptoms. The best-studied and most effective medications include gabapentin, SSRIs (especially paroxetine), and serotonin-norepinephrine reuptake inhibitors (venlafaxine and desvenlafaxine).^24,27

OBG Management: Is there any evidence that AIs impair cognitive function in postmenopausal women?

Dr. Kaunitz: Because estrogen is important for cognition, one might anticipate that the profound reduction in background estrogen associated with AI use would impair cognition. Fortunately, the evidence to date is reassuring. Substudies of the BIG trial and the Tamoxifen and Exemestane Adjuvant Multinational Trial indicate that, compared with tamoxifen (which is associated with declines in cognitive function in postmenopausal women), letrozole and exemestane do not diminish cognitive function.^28,29

OBG Management: Overall, what is the typical impact of an AI on a woman’s quality of life?

Dr. Kaunitz: Most women do very well on an AI, finding it easier to tolerate than tamoxifen, as we have discussed. However, a significant minority of women is seriously bothered by the adverse effects, with arthralgias usually leading the pack of complaints.^30,31

OBG Management: Do some women discontinue adjuvant endocrine therapy because of adverse effects?

Dr. Kaunitz: Regrettably, the answer is “Yes.” A recent study from Kaiser Permanente of northern California found that roughly 50% of women who are prescribed adjuvant endocrine therapy with tamoxifen or an AI discontinue the drug early.³²

OBG Management: What can an ObGyn do to encourage compliance with and completion of AI therapy?

Dr. Kaunitz: First, it is critical that patients understand that AIs are lifesaving drugs. As a recent paper points out, early discontinuation or noncompliance with AI therapy is associated with higher mortality.³³

Clinicians should also help breast cancer patients understand what common side effects to anticipate with these medications.

Finally, clinicians who understand the financial toll a breast cancer diagnosis and treatment can take are better positioned to help women overcome challenges that may interfere with long-term compliance with AI therapy.

OBG Management: Do you expect the use of AIs in breast cancer survivors to become more commonplace?

Dr. Kaunitz: Given how common breast cancer is, and given the new ASCO guidelines and the extensive literature upon which they are based, ObGyns will be seeing more women using AIs. Although we are not the physicians who prescribe AIs, we need to remain up to date on their benefits and side effects. This important class of drugs is positioned to improve outcomes for postmenopausal women with breast cancer.

We want to hear from you! Tell us what you think.

Think breast cancer survivors are unlikely to show up in your practice? You should think again.

At last official count, 2.5 million women in the United States had a history of breast cancer.¹ Most of them are now free of malignancy, but others are still grappling with the disease in some form or fashion.² All need continuing health care.

Roughly two thirds of women who have breast cancer have disease that is hormone-receptor–positive.^2,3 Recently updated guidelines from the American Society of Clinical Oncology (ASCO) recommend that adjuvant therapy for postmenopausal women who have hormone-positive breast cancer include an aromatase inhibitor (AI) (see a summary of these guidelines on page 36). That makes it likely that a good number of breast cancer survivors who visit your practice are taking one of these medications: anastrozole (Arimidex), letrozole (Femara), or exemestane (Aromasin). These drugs are antiestrogens, given to postmenopausal women to reduce the likelihood of disease recurrence and progression.

The antiestrogenic properties of these drugs are what make them lifesavers. But the same qualities can create a range of health issues, from increased risk of osteoporosis and fracture to vasomotor and joint symptoms. And although ObGyns are not the physicians who prescribe these drugs, you may be the provider one of these women consults about their side effects and related issues.

To find out the latest on the management of women who are taking one of these agents, we inserted ourselves into the busy schedule of Andrew M. Kaunitz, MD, who agreed to address some fundamental—and some not so basic—questions about the drugs. In this extended Q&A, Dr. Kaunitz touches on mechanism of action, benefits versus risks, common side effects, compliance with therapy, and the ill effects of early discontinuation.

Aromatase inhibitors are better than tamoxifen at reducing the risk of breast cancer recurrence in postmenopausal women who have hormone-receptor–positive disease. But, they increase the risk of osteoporosis and fracture and often cause arthralgias and other complaints that ObGyn practitioners may be called upon to manage.

OBG Management: What is the overall aim of adjuvant endocrine therapy in the setting of breast cancer?

Dr. Kaunitz: Endocrine therapy—specifically, use of an AI—prevents the stimulation of breast cancer cells by endogenous estrogen. In other words, aromatase inhibitors suppress the growth of cancer cells that have estrogen receptors. These drugs also inhibit aromatase near any breast tumor and reduce estrogen levels in breast tissue.

OBG Management: What is the mechanism of action of adjuvant endocrine therapy?

Dr. Kaunitz: In postmenopausal women, androgens are converted to estrogens via the aromatase enzyme, which is present in adipose tissue and other sites. By blocking this enzyme, AIs reduce endogenous estrogen levels by as much as 95%.⁴

OBG Management: How does that differ from the mechanism of action of tamoxifen, another drug used in breast cancer patients?

Dr. Kaunitz: Tamoxifen is a selective estrogen receptor modulator (SERM). It blocks estrogen in breast tissue selectively, by competitively binding to estrogen receptors.⁵ However, tamoxifen has estrogenic effects in the uterus, bone, and liver, as well as other tissues.

The efficacy of AIs in preventing breast cancer recurrence in the first 2 years after breast cancer surgery is higher than that of tamoxifen. And unlike tamoxifen, the AIs do not increase the risk of venous thromboembolism or cause endometrial disease.

OBG Management: What effects do aromatase inhibitors have in premenopausal women?

Dr. Kaunitz: These agents are not recommended for use in premenopausal women because, in that population, the lion’s share of estrogen production takes place in the ovary rather than in adipose tissue and muscle. If you were to administer an AI to a premenopausal woman, the reduced hypothalamic and pituitary estrogen feedback could lead to ovarian stimulation—which could increase ovarian steroid production.

OBG Management: What about women who become amenorrheic as a result of chemotherapy or other cancer treatment? Do most oncologists assume that they are postmenopausal and prescribe an aromatase inhibitor?

Dr. Kaunitz: Clinicians should not assume that chemotherapy-induced amenorrhea signals permanent cessation of ovarian function. It is common for ovarian function to return in this setting. Accordingly, follicle-stimulating hormone (FSH) and estradiol levels should be assessed before an AI is considered as adjuvant therapy. Some investigators have suggested that the use of an AI in women who have chemotherapy-induced amenorrhea may actually increase the likelihood that ovarian function will return.⁶

OBG Management: Do all AIs produce the same effects?

Dr. Kaunitz: The AIs used in women with breast cancer are third-generation drugs. These AIs are classified as steroidal (type 1; exemestane) or nonsteroidal (type 2; anastrozole, letrozole). Exemestane, a steroid derived from androstenedione, inhibits the aromatase enzyme irreversibly. The nonsteroidal AIs are reversible.

Although all three AIs have numerous similarities, there are other distinctions between them in pharmacokinetics, mechanism of action, and toxicity—so they are not completely interchangeable.⁷ However, from our perspective as ObGyns caring for breast cancer survivors, we can assume that all three AIs will have similar effects on skeletal health and produce similar side effects in postmenopausal women.

How much do we know about these drugs?

OBG Management: How long does a woman typically take an AI?

Dr. Kaunitz: At present, in women treated for early-stage, hormone-positive breast cancer, the optimal duration of treatment is unknown. Most oncologists prescribe an AI for 5 years, the length of treatment in a prominent trial of the drugs.⁸

OBG Management: Is that duration likely to increase as more data come in?

Dr. Kaunitz: The optimal duration of adjuvant AI therapy will be determined by the findings of long-term clinical trials. The National Surgical Adjuvant Breast and Bowel Project B-42 trial may provide new insights into optimal duration of AI treatment after initial tamoxifen therapy.⁹

OBG Management: How thoroughly have AIs been studied in regard to their use in breast cancer survivors and women who have early-stage disease? How would you characterize the quantity and quality of data that we have so far?

Dr. Kaunitz: AIs have been extensively studied. The most important clinical trials of AIs in this setting, including the Anastrozole, Tamoxifen Alone or in Combination (ATAC) trial (over 6,000 participants, median follow-up of 100 months) and the Breast International Group (BIG) trial (almost 5,000 participants, median follow-up of 76 months) have been detailed in the recent ASCO report.¹⁰ These two large landmark trials, in particular, formed the basis for ASCO’s recommendations to routinely incorporate AIs into the therapy of postmenopausal women who have hormone-receptor–positive breast cancer.

OBG Management: In treating breast cancer, what other applications are AIs used for?

Dr. Kaunitz: AIs appear to be slightly more effective than tamoxifen in treating postmenopausal women who have metastatic breast cancer.¹¹

They are approved as first-line therapy for breast cancer in:

• postmenopausal women who have hormone-receptor–positive disease
• postmenopausal women who have locally advanced disease when the hormone receptor is unknown
• postmenopausal women who have metastatic disease.

In addition, they are approved as second-line treatment of advanced breast cancer in postmenopausal women who have disease progression following tamoxifen therapy.¹²

How effective is AI therapy?

OBG Management: What do we know about the efficacy of these drugs?

Dr. Kaunitz: Most of the studies that have explored efficacy compare an AI with tamoxifen rather than with placebo. In the ATAC trial, after a median follow-up of 33 months, women who were taking anastrozole for early-stage breast cancer had longer disease-free survival and time to recurrence and a lower incidence of contralateral breast cancer than did women taking tamoxifen.⁸

After 4 years of follow-up in the ATAC trial, women taking anastrozole continued to have more favorable disease-free survival (86.9% vs 84.5% for anastrozole and tamoxifen, respectively; hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.76–0.99; P =.03).¹³ They also had a more favorable time to recurrence than did women taking tamoxifen (HR, 0.83; 95% CI, 0.71–0.96; P =.015). And women taking anastrozole had a lower incidence of contralateral breast cancer, as well, although this different did not achieve statistical significance (HR, 0.62; 95% CI, 0.38–1.02; P =.062).¹³

In the BIG study, women taking letrozole had a 5-year disease-free survival estimate of 84.0%, compared with 81.4% for women taking tamoxifen.¹⁴ In addition, women taking letrozole were significantly less likely than those taking tamoxifen to experience an event that ended a period of disease-free survival (HR, 0.81; 95% CI, 0.70–0.93; P =.003), especially the event of distant recurrence (HR, 0.73; 95% CI, 0.60–0.88; P =.001).¹⁴

And a phase-3 study of exemestane versus tamoxifen in women who had metastatic breast cancer found that the AI produced a superior response rate (46% vs 31% for exemestane and tamoxifen, respectively; odds ratio [OR], 1.85; 95% CI, 1.21–2.82; P =.005). In addition, median progression-free survival was greater with exemestane (9.9 months; 95% CI, 8.7–11.8 months) than with tamoxifen (5.8 months; 95% CI, 5.3–8.1 months). However, there was no difference between arms in progression-free survival or overall survival.

How well tolerated are AIs?

OBG Management: What adverse effects are associated with AIs?

Dr. Kaunitz: Although AIs, overall, are safe medications, their use is associated with a number of adverse events. The most prominent side effects include arthralgias and hot flushes, while the most serious health impact appears to be a decrease in bone mineral density (BMD).

However, the drugs are generally perceived as being easier to tolerate than tamoxifen. That’s because endometrial cancer, vaginal bleeding and discharge, cerebrovascular events, venous thromboembolic events, and hot flushes all are less common among women taking an AI than among those taking tamoxifen.^8,13

For overweight women, who face an elevated baseline risk of thromboembolism, the availability of AIs represents a major advantage over tamoxifen. Similarly, AIs offer advantages over tamoxifen for women who have an intact uterus. In addition, postmenopausal women who are taking a selective serotonin reuptake inhibitor (SSRI) such as paroxetine should take an AI rather than tamoxifen, because the concomitant use of SSRIs attenuates the efficacy of tamoxifen.¹⁵

What can be done about the most prominent risks?

OBG Management: Let’s focus on what’s probably the best-known adverse effect of AIs—the heightened risk of osteoporosis and fracture. How significant is this effect?

Dr. Kaunitz: Because use of an AI is associated with a profound reduction in endogenous estrogen levels, it also decreases BMD and can lead to osteoporotic fractures. All major phase-3 trials of adjuvant use of AIs in women who have early breast cancer found an increased risk of fracture, with no significant differences between AIs.¹⁶

Fortunately, bisphosphonate therapy (oral or intravenous) has been found to reduce bone loss associated with AI therapy.^17,18

Assessing baseline BMD is important as women initiate AI therapy. Although no consensus exists regarding follow-up BMD assessment in the setting of AI use, an interval of 2 years is prudent, with the follow-up study preferably performed at the same imaging center and by the same technician as the first. If baseline osteoporosis is observed at the lumbar spine or hip, bisphosphonate therapy is appropriate. If a woman taking an AI has low bone mass (osteopenia) but not osteoporosis, bisphosphonate therapy should be considered if any of the following risk factors are present:

• advanced age
• history of fracture
• glucocorticoid therapy
• parental history of hip fracture
• low body weight
• current smoking status
• excess alcohol consumption
• rheumatoid arthritis
• known risk factors for secondary osteoporosis.¹⁹

In breast cancer survivors initiating or continuing AI therapy, it is also appropriate to check a serum vitamin D level and ensure that intake of this nutrient is adequate.

Bisphosphonates may offer oncologic benefits, as well; preliminary evidence suggests that the drugs may prevent recurrence of the cancer and prolong survival.²⁰

OBG Management: What can an ObGyn offer to a woman who complains of significant AI-related arthralgia?

Dr. Kaunitz: Bone and joint symptoms, including aches, pain, and stiffness that is bilateral and not associated with other evidence of rheumatologic disorders, are among the most common side effects of AI therapy. On the plus side of the equation, these symptoms are more likely to be mild to moderate than severe. On the negative side, no specific treatment has been found to be effective in relieving these symptoms, which usually resolve within 2 months or so after discontinuing AI therapy.¹⁰

OBG Management: Do AIs have a negative impact on cardiovascular health?

Dr. Kaunitz: Unlike tamoxifen, AIs do not increase the risk of thromboembolic disease. Although the use of an AI may modestly increase the risk of ischemic cardiovascular disease (and lipid changes), compared with tamoxifen, AIs do not appear to increase cardiovascular risk compared with placebo.^21,22

OBG Management: Do the antiestrogenic effects of AIs have a significant impact on vaginal health and sexual desire?

Dr. Kaunitz: A review of published reports did not find that the use of AIs has a predictable impact on vaginal dryness or sexual desire.¹⁰ However, symptomatic genital atrophy is common in postmenopausal breast cancer survivors, whether or not they use adjuvant therapy.

Although the FDA considers the use of any estrogen (systemic or vaginal) following a diagnosis of breast cancer to be contraindicated, some breast cancer survivors who have symptomatic genital atrophy express an interest in the use of vaginal estrogen. Use of 25-μg estradiol tablets (Vagifem) is associated with a short-term increase in serum estradiol levels.²³ This finding has reinforced caution among medical oncologists about the safety of vaginal estrogen in breast cancer survivors. (The 25-μg tablets are no longer marketed.) The lowest dosage of vaginal estrogen available for the treatment of genital atrophy is found in 10-μg estradiol tablets (Vagifem) and the estradiol (2-mg) 3-month vaginal ring (Estring). Nonetheless, in the absence of data, oncologists will likely continue to be concerned that even the lowest dosage of vaginal estrogen could attenuate the favorable impact of AIs on breast cancer. Accordingly, use of vaginal lubricants and moisturizers are the mainstay strategy for symptomatic genital atrophy.

OBG Management: What about the ubiquitous hot flush? Vasomotor symptoms may be more common in women who take tamoxifen, but women on AIs are also bothered by flushes. What are the alternatives to estrogen therapy?

Dr. Kaunitz: Both nonprescription and prescription alternatives are available. Nonprescription options include soy extract and red clover isoflavones, black cohosh, and Chinese herbs. However, none of these over-the-counter approaches has been found to be more effective than placebo in the treatment of menopausal hot flushes.^24-26

As for prescription nonhormonal options, ObGyns should recognize that all such treatments are off-label and that none attain the efficacy of hormone therapy in the treatment of vasomotor symptoms. The best-studied and most effective medications include gabapentin, SSRIs (especially paroxetine), and serotonin-norepinephrine reuptake inhibitors (venlafaxine and desvenlafaxine).^24,27

OBG Management: Is there any evidence that AIs impair cognitive function in postmenopausal women?

Dr. Kaunitz: Because estrogen is important for cognition, one might anticipate that the profound reduction in background estrogen associated with AI use would impair cognition. Fortunately, the evidence to date is reassuring. Substudies of the BIG trial and the Tamoxifen and Exemestane Adjuvant Multinational Trial indicate that, compared with tamoxifen (which is associated with declines in cognitive function in postmenopausal women), letrozole and exemestane do not diminish cognitive function.^28,29

OBG Management: Overall, what is the typical impact of an AI on a woman’s quality of life?

Dr. Kaunitz: Most women do very well on an AI, finding it easier to tolerate than tamoxifen, as we have discussed. However, a significant minority of women is seriously bothered by the adverse effects, with arthralgias usually leading the pack of complaints.^30,31

OBG Management: Do some women discontinue adjuvant endocrine therapy because of adverse effects?

Dr. Kaunitz: Regrettably, the answer is “Yes.” A recent study from Kaiser Permanente of northern California found that roughly 50% of women who are prescribed adjuvant endocrine therapy with tamoxifen or an AI discontinue the drug early.³²

OBG Management: What can an ObGyn do to encourage compliance with and completion of AI therapy?

Dr. Kaunitz: First, it is critical that patients understand that AIs are lifesaving drugs. As a recent paper points out, early discontinuation or noncompliance with AI therapy is associated with higher mortality.³³

Clinicians should also help breast cancer patients understand what common side effects to anticipate with these medications.

Finally, clinicians who understand the financial toll a breast cancer diagnosis and treatment can take are better positioned to help women overcome challenges that may interfere with long-term compliance with AI therapy.

OBG Management: Do you expect the use of AIs in breast cancer survivors to become more commonplace?

Dr. Kaunitz: Given how common breast cancer is, and given the new ASCO guidelines and the extensive literature upon which they are based, ObGyns will be seeing more women using AIs. Although we are not the physicians who prescribe AIs, we need to remain up to date on their benefits and side effects. This important class of drugs is positioned to improve outcomes for postmenopausal women with breast cancer.

We want to hear from you! Tell us what you think.

Late last year, the US Preventive Services Task Force (USPSTF) sparked a nationwide controversy when it announced that it was recommending against routine screening mammography for women younger than age 50.¹ Indeed, that’s a recommendation that many other organizations, including the American Cancer Society (ACS),² the American College of Obstetricians and Gynecologists (ACOG),³ and the National Comprehensive Cancer Network (NCCN),⁴ disagree with. But the age at which women should begin routine mammography isn’t the only controversial question. Experts disagree on the benefits of breast self-examination, the optimal frequency of clinical breast exams, and the use of digital mammography—among other issues. This evidence-based review can help you cut through the confusion.

CASE Carrie, a 39-year-old woman who has never been pregnant, comes in for an annual Pap smear and gynecologic exam. She has a negative past medical history, but a positive family history for breast cancer—both her mother and 1 of her sisters had the disease. How would you assess Carrie’s risk of breast cancer, and what preventive measures would you recommend?

Use this predictive model to pinpoint your patient’s risk

When making decisions regarding primary prevention of and screening for breast cancer, an accurate assessment of risk is critical. Many predictive models have been developed with that in mind. The most widely studied, the Gail model, incorporates a number of important risk factors (TABLE 1), including age; race; family history; reproductive factors such as age of menarche, menopause, and first childbirth; and previous history of breast biopsy and atypical findings, to calculate a woman’s 5-year risk.⁵

A risk calculator (the Breast Cancer Risk Assessment Tool) based on the Gail model is available on the National Cancer Institute’s Web site, at http://www.cancer.gov/bcrisktool. Generally, a score ≥1.66%,⁵ which indicates that a patient has at least a 1.66% chance of developing breast cancer over the next 5 years, is considered high risk.^6,7

CASE Carrie’s 2 first-degree relatives affected by breast cancer and her nulliparous status place her at increased risk. Further questioning reveals a particularly strong family history, as both relatives were diagnosed before the age of 50 (her mom at 45 years of age and her sister, at 39). Carrie’s 5-year risk is 1.8%.

TABLE 1
Risk factors for breast cancer^5,29

All women can benefit from these preventive measures

As primary care physicians, we have a responsibility to stress lifestyle modification as the mainstay of breast cancer prevention. Whether or not a woman is at high risk, advise her that maintaining a normal weight, exercising vigorously, limiting alcohol consumption, and breastfeeding are evidence-based methods of primary prevention. Diets low in fat and high in fiber may be associated with a lower risk of invasive breast cancer, but there is no conclusive evidence to support specific dietary interventions to reduce the risk.^8-11 Nor has a link between active or passive smoking, antioxidants, or fruit and vegetable intake been firmly established.¹²

There is a clear association between prolonged estrogen exposure and breast cancer, however. Many reproductive factors, such as early menarche, late menopause, later age at time of first full-term pregnancy, and nulliparity, increase a woman’s exposure to endogenous estrogen—and her risk of developing breast cancer.^12,13

Exposure to exogenous estrogen is also linked to the development of breast cancer. In 2002, the Women’s Health Initiative (WHI) was stopped early after a report was released stating that the risks of hormone replacement therapy (HRT)—a higher incidence of cardiovascular events, stroke, and venous thromboembolism, as well as breast cancer—outweighed the benefits.¹⁴ Subsequent analyses have found a relationship between the declining incidence of breast cancer and the marked decrease in HRT use prompted by the WHI report. While causality has not been firmly established, multiple studies strongly suggest it.^15,16

The association between oral contraceptives (OCs) and breast cancer is more controversial. Some studies have found an increased breast cancer risk among OC users, but both the relative risk and absolute risk were found to be very small and to dissipate 10 years after stopping OC use. More recent studies with newer formulations containing lower doses of estrogen have failed to show an increased risk.⁸

Breast cancer screening: The parameters have changed

Various organizations have published guidelines for breast cancer screening (TABLE 2), and all are somewhat different. Here’s what you need to know.

Breast self-examination (BSE), which women were previously advised to perform monthly, has not been shown to improve mortality in any age group, and is no longer routinely recommended.¹⁷ While both the USPSTF and the Canadian Task Force on Preventive Health Care recommend against teaching women BSE, the ACS, ACOG, and NCCN encourage self-examination—particularly among women older than 40 years.^1-4,17,18

Clinical breast examination has an average sensitivity of 50% and detects approximately 5% of mammographically occult cancers.¹⁹ It is still not clear whether clinical breast exams save lives, however—a finding that is reflected in the USPSTF’s “I” (insufficient evidence to assess the benefits and harms) recommendation.¹ Other consensus guidelines still recommend clinical breast examination, albeit at varying frequencies.

Screening mammography decreases mortality rates by anywhere from 28% to 65%, depending on the statistical model used.²⁰ The benefit is greatest in women between the ages of 50 and 69 years, however, and most groups agree that mammography every 1 to 2 years is advisable for this age group. (There is limited data on the value of mammography for women 70 years of age and older, and no consensus on the age at which to stop screening.^1,21) But because the mortality benefit from screening mammography is lower for women aged 40 to 49, guidelines for this age group are more controversial.

Mammography’s sensitivity is affected by a variety of factors, including age and menopausal status, prior breast surgery or radiation, breast density, and the experience of the radiologist. Women in their 40s have denser breast tissue than older women, making mammography less sensitive for this age group. Because of that, and because the overall incidence of breast cancer is lower for women younger than 50, some argue that screening mammography for women between the ages of 40 and 49 years leads to unacceptably high false-positive rates (9.8% annually²²) and that the harm associated with mammography may outweigh the benefit. Others counter that tumors in younger women tend to be more aggressive and faster growing, making early detection even more critical than for older women.

What should you advise women in this age group? You might point out that the USPSTF recommends against routine screening, but indicates that the decision to begin (or defer) routine mammography before age 50 should be individualized, based on the needs and values of each patient.¹

Digital mammography. A recent study of more than 43,000 women demonstrated that digital mammography is more accurate than film—but only for certain groups: These include women <50 years of age, women with dense breasts, and pre- and perimenopausal women. ²³ Because it is still not clear whether the increased accuracy will translate into a mortality benefit, more research is needed before digital mammography is widely adopted. The USPSTF maintains that there is insufficient evidence to assess the benefits and harms of using either digital mammography or magnetic resonance imaging (MRI) rather than film mammography to screen for breast cancer.¹

MRI. In 2007, the ACS published guidelines on the use of MRI as an adjunct to mammography for breast cancer screening in high-risk women.²⁴ According to ACS guidelines, screening MRI should be offered to patients with a known BRCA 1 or 2 mutation (5%-10% of all breast cancers are associated with a mutation in the BRCA 1 or BRCA 2 gene, which is transmitted in an autosomal dominant pattern⁶). It also should be offered to those with a strong family history, or a lifetime risk of developing breast cancer that is >20% to 25%. And finally, MRI should be offered to women who had chest wall radiation when they were between the ages of 10 and 30 years—another significant risk factor for breast cancer—and those with other genetic syndromes that increase their lifetime risk of breast cancer.²⁴

Evidence is insufficient for or against MRI screening for women with a personal history of breast cancer, atypical hyperplasia, or lobular carcinoma in situ, however, and neither breast ultrasound (which is generally used diagnostically, not for screening purposes) nor MRI has been shown to be helpful as a screening tool in women with <15% lifetime risk of developing breast cancer.^24,25

TABLE 2
Guidelines for breast cancer screening for women with average risk

When to consider chemoprevention

For women like Carrie, who are at high risk of developing breast cancer, selective estrogen receptor modulator (SERM) therapy and surgical interventions may be options to consider. The Breast Cancer Prevention Trial demonstrated the efficacy of tamoxifen as a preventive agent. This landmark trial showed that for high-risk women older than 35, 5 years of tamoxifen therapy can reduce the incidence of invasive breast cancer by nearly 50%.²⁶

Women with the BRCA 1 or 2 mutation—all of whom should be offered genetic counseling—were included in the study. Tamoxifen reduced the incidence of breast cancer in BRCA 2 carriers by 62%, the researchers found, but did not reduce risk in carriers of the BRCA 1 gene. This is likely due to the high prevalence of estrogen receptor-negative breast cancers among BRCA 1 carriers.²⁶

More recently, the Study of Tamoxifen and Raloxifene (STAR) trial compared the efficacy of tamoxifen and raloxifene, a second-generation SERM, in high-risk postmenopausal women ages 35 and older. The drugs were found to be equally effective in reducing the risk of invasive breast cancer, but raloxifene had a better side effect profile, with a lower incidence of thromboembolism and cataracts. ²⁷

What the guidelines call for. In 2003, the USPSTF recommended that clinicians discuss chemoprevention with women at high risk for breast cancer and low risk for adverse effects of SERMs.²⁸

The most recent update to the NCCN breast cancer risk reduction guidelines recommends that clinicians offer tamoxifen to premenopausal women with a 5-year projected breast cancer risk ≥1.7% and offer tamoxifen or raloxifene to high-risk postmenopausal women.²⁹ It is worth noting, however, that SERMs can have significant adverse effects, including venous thromboembolism, stroke, cataracts, uterine malignancy, and hot flashes, while lifestyle modifications and the avoidance of HRT have few, if any, negative effects.

CASE After consultation with a genetic counselor, Carrie underwent testing for both the BRCA 1 and BRCA 2 mutations. She tested negative for both. She declined chemoprevention and prophylactic surgery, opting for enhanced screening with yearly mammography and MRI and lifestyle modification instead.

When a mass is found

For women ages 30 or older with palpable masses or solid masses ≥2 cm found on imaging, core needle biopsy is recommended.^30,31 Biopsy is indicated for women younger than 30 as well, if the mass is >2 cm or imaging is suspicious. In general, a needle biopsy read as benign is considered adequate for diagnostic purposes only if the lesion appeared benign on imaging.

For lesions shown to be cystic on imaging, recommendations for follow-up or additional testing are based on the characteristics of the cyst. For simple cysts, 2- to 4-month follow up for stability, followed by routine screening, is adequate.²¹ Additional evaluation of complex cysts is indicated, including aspiration for complicated cysts and biopsy for complex cysts. After aspiration, surgical excision of bloody aspirates or persistent masses is recommended.^30,31

Staging using the TNM system
The TNM (tumor, node, metastases) classification system is used for the staging of breast cancer:

• T refers to the tumor type, size, and extent of local involvement
• N describes regional lymph node involvement
• M refers to distant metastases.

The TNM classifications are also grouped by stage (I through IV).,

Lumpectomy and sentinel node mapping with excision is the preferred method for staging of early-stage breast cancer without palpable lymphadenopathy—provided that the surgical team has documented experience with sentinel node biopsy.³² Sentinel node biopsy is preferred because of its safety, low (<10%) false negative rate, and decreased morbidity compared with full axillary dissection, although dissection is recommended for patients with more advanced cancer or a positive sentinel node.³² The comparative effects of sentinel node biopsy vs axillary node dissection on tumor recurrence and patient survival are not known.³³

Testing for tumor markers such as estrogen and progesterone receptors and human epidermal growth factor receptor 2 (HER2) expression status in biopsy-proven breast cancer is now the standard of care. Seventy percent of breast cancers are estrogen receptor-positive, with increasing frequency associated with older age.³⁴ Estrogen/progesterone receptor positivity is associated with a more favorable outcome, and multiple hormonal therapies can be aimed at these receptors.³⁴ While HER2 overexpression—which occurs in 15% to 30% of newly diagnosed breast cancers³⁵—is associated with more aggressive tumors, women with this type of tumor cell can benefit from trastuzumab, an anti-HER2 drug.³⁶

Key factors that affect prognosis

Important factors affecting prognosis and treatment of localized breast cancer are tumor size, age and menopausal status, tumor expression of hormone receptors and/ or the HER2 protein, as well as the status of the draining axillary nodes. Factors that predict a greater chance of recurrence include the spread of disease to axillary nodes, larger tumor size, invasive histology, inflammatory pathology, lack of estrogen/progesterone receptors, and age <50 years or premenopausal status.

Treatment options include surgical resection, radiation, and systemic adjuvant therapy in the form of chemotherapy, endocrine therapy, or anti-HER2 monoclonal antibodies.³⁷ (For more on treatment, see “Surgery, radiation, and systemic therapy: Making the most of what’s in our arsenal” at jfponline.com.)

Don’t overlook quality-of-life issues
Follow-up of breast cancer patients should go beyond treatment and work-up for recurrence and metastatic disease to focus on health and lifestyle issues, such as stress reduction, mood, smoking cessation, diet and exercise, treatment of hot flashes, sexual dysfunction, and bone health. A recent study found both reduced recurrence and increased survival in women receiving psychological interventions to improve quality-of-life measures after an 11-year follow-up.³⁸

Refer women to targeted Web sites such as the National Breast Cancer Awareness Month organization (http://www.nbcam.org/), the National Breast Cancer Foundation (http://community.nationalbreastcancer.org/), and the Susan G. Komen Breast Cancer Foundation (http://ww5.komen.org/). Offer treatment for bothersome symptoms. Hot flashes and depression, for example, often related to endocrine therapy, can be treated with selective serotonin reuptake inhibitors (SSRIs). That said, some SSRIs decrease the active metabolite of tamoxifen by inhibiting CYP2D6 enzyme and must, therefore, be used with caution. However, venlafaxine and citalopram are less likely to alter tamoxifen metabolism than other SSRIs.³⁹

CASE When Carrie was 47, she had an abnormal MRI of the left breast. Core needle biopsy and pathology of the lesion revealed an estrogen and progesterone receptor-positive tumor that was negative for HER2 overexpression. She underwent lumpectomy, which revealed a 1.5 cm tumor, followed by a negative sentinel node biopsy, and was diagnosed with stage I (T1N0M0) breast cancer. Carrie had radiation after surgery; she did not require chemotherapy, but was told to take tamoxifen for 5 years. This adjuvant endocrine therapy led to hot flashes and depression, both of which were successfully treated with venlafaxine. Carrie is currently cancer-free and participates in a breast cancer survivor program that includes regular visits with her primary physician and her oncologist.

CORRESPONDENCE Denise Sur, MD, 1920 Colorado Avenue, Santa Monica, CA 90404; dsur@mednet.ucla.edu 

Late last year, the US Preventive Services Task Force (USPSTF) sparked a nationwide controversy when it announced that it was recommending against routine screening mammography for women younger than age 50.¹ Indeed, that’s a recommendation that many other organizations, including the American Cancer Society (ACS),² the American College of Obstetricians and Gynecologists (ACOG),³ and the National Comprehensive Cancer Network (NCCN),⁴ disagree with. But the age at which women should begin routine mammography isn’t the only controversial question. Experts disagree on the benefits of breast self-examination, the optimal frequency of clinical breast exams, and the use of digital mammography—among other issues. This evidence-based review can help you cut through the confusion.

CASE Carrie, a 39-year-old woman who has never been pregnant, comes in for an annual Pap smear and gynecologic exam. She has a negative past medical history, but a positive family history for breast cancer—both her mother and 1 of her sisters had the disease. How would you assess Carrie’s risk of breast cancer, and what preventive measures would you recommend?

Use this predictive model to pinpoint your patient’s risk

When making decisions regarding primary prevention of and screening for breast cancer, an accurate assessment of risk is critical. Many predictive models have been developed with that in mind. The most widely studied, the Gail model, incorporates a number of important risk factors (TABLE 1), including age; race; family history; reproductive factors such as age of menarche, menopause, and first childbirth; and previous history of breast biopsy and atypical findings, to calculate a woman’s 5-year risk.⁵

A risk calculator (the Breast Cancer Risk Assessment Tool) based on the Gail model is available on the National Cancer Institute’s Web site, at http://www.cancer.gov/bcrisktool. Generally, a score ≥1.66%,⁵ which indicates that a patient has at least a 1.66% chance of developing breast cancer over the next 5 years, is considered high risk.^6,7

CASE Carrie’s 2 first-degree relatives affected by breast cancer and her nulliparous status place her at increased risk. Further questioning reveals a particularly strong family history, as both relatives were diagnosed before the age of 50 (her mom at 45 years of age and her sister, at 39). Carrie’s 5-year risk is 1.8%.

TABLE 1
Risk factors for breast cancer^5,29

All women can benefit from these preventive measures

As primary care physicians, we have a responsibility to stress lifestyle modification as the mainstay of breast cancer prevention. Whether or not a woman is at high risk, advise her that maintaining a normal weight, exercising vigorously, limiting alcohol consumption, and breastfeeding are evidence-based methods of primary prevention. Diets low in fat and high in fiber may be associated with a lower risk of invasive breast cancer, but there is no conclusive evidence to support specific dietary interventions to reduce the risk.^8-11 Nor has a link between active or passive smoking, antioxidants, or fruit and vegetable intake been firmly established.¹²

There is a clear association between prolonged estrogen exposure and breast cancer, however. Many reproductive factors, such as early menarche, late menopause, later age at time of first full-term pregnancy, and nulliparity, increase a woman’s exposure to endogenous estrogen—and her risk of developing breast cancer.^12,13

Exposure to exogenous estrogen is also linked to the development of breast cancer. In 2002, the Women’s Health Initiative (WHI) was stopped early after a report was released stating that the risks of hormone replacement therapy (HRT)—a higher incidence of cardiovascular events, stroke, and venous thromboembolism, as well as breast cancer—outweighed the benefits.¹⁴ Subsequent analyses have found a relationship between the declining incidence of breast cancer and the marked decrease in HRT use prompted by the WHI report. While causality has not been firmly established, multiple studies strongly suggest it.^15,16

The association between oral contraceptives (OCs) and breast cancer is more controversial. Some studies have found an increased breast cancer risk among OC users, but both the relative risk and absolute risk were found to be very small and to dissipate 10 years after stopping OC use. More recent studies with newer formulations containing lower doses of estrogen have failed to show an increased risk.⁸

Breast cancer screening: The parameters have changed

Various organizations have published guidelines for breast cancer screening (TABLE 2), and all are somewhat different. Here’s what you need to know.

Breast self-examination (BSE), which women were previously advised to perform monthly, has not been shown to improve mortality in any age group, and is no longer routinely recommended.¹⁷ While both the USPSTF and the Canadian Task Force on Preventive Health Care recommend against teaching women BSE, the ACS, ACOG, and NCCN encourage self-examination—particularly among women older than 40 years.^1-4,17,18

Clinical breast examination has an average sensitivity of 50% and detects approximately 5% of mammographically occult cancers.¹⁹ It is still not clear whether clinical breast exams save lives, however—a finding that is reflected in the USPSTF’s “I” (insufficient evidence to assess the benefits and harms) recommendation.¹ Other consensus guidelines still recommend clinical breast examination, albeit at varying frequencies.

Screening mammography decreases mortality rates by anywhere from 28% to 65%, depending on the statistical model used.²⁰ The benefit is greatest in women between the ages of 50 and 69 years, however, and most groups agree that mammography every 1 to 2 years is advisable for this age group. (There is limited data on the value of mammography for women 70 years of age and older, and no consensus on the age at which to stop screening.^1,21) But because the mortality benefit from screening mammography is lower for women aged 40 to 49, guidelines for this age group are more controversial.

Mammography’s sensitivity is affected by a variety of factors, including age and menopausal status, prior breast surgery or radiation, breast density, and the experience of the radiologist. Women in their 40s have denser breast tissue than older women, making mammography less sensitive for this age group. Because of that, and because the overall incidence of breast cancer is lower for women younger than 50, some argue that screening mammography for women between the ages of 40 and 49 years leads to unacceptably high false-positive rates (9.8% annually²²) and that the harm associated with mammography may outweigh the benefit. Others counter that tumors in younger women tend to be more aggressive and faster growing, making early detection even more critical than for older women.

What should you advise women in this age group? You might point out that the USPSTF recommends against routine screening, but indicates that the decision to begin (or defer) routine mammography before age 50 should be individualized, based on the needs and values of each patient.¹

Digital mammography. A recent study of more than 43,000 women demonstrated that digital mammography is more accurate than film—but only for certain groups: These include women <50 years of age, women with dense breasts, and pre- and perimenopausal women. ²³ Because it is still not clear whether the increased accuracy will translate into a mortality benefit, more research is needed before digital mammography is widely adopted. The USPSTF maintains that there is insufficient evidence to assess the benefits and harms of using either digital mammography or magnetic resonance imaging (MRI) rather than film mammography to screen for breast cancer.¹

MRI. In 2007, the ACS published guidelines on the use of MRI as an adjunct to mammography for breast cancer screening in high-risk women.²⁴ According to ACS guidelines, screening MRI should be offered to patients with a known BRCA 1 or 2 mutation (5%-10% of all breast cancers are associated with a mutation in the BRCA 1 or BRCA 2 gene, which is transmitted in an autosomal dominant pattern⁶). It also should be offered to those with a strong family history, or a lifetime risk of developing breast cancer that is >20% to 25%. And finally, MRI should be offered to women who had chest wall radiation when they were between the ages of 10 and 30 years—another significant risk factor for breast cancer—and those with other genetic syndromes that increase their lifetime risk of breast cancer.²⁴

Evidence is insufficient for or against MRI screening for women with a personal history of breast cancer, atypical hyperplasia, or lobular carcinoma in situ, however, and neither breast ultrasound (which is generally used diagnostically, not for screening purposes) nor MRI has been shown to be helpful as a screening tool in women with <15% lifetime risk of developing breast cancer.^24,25

TABLE 2
Guidelines for breast cancer screening for women with average risk

When to consider chemoprevention

For women like Carrie, who are at high risk of developing breast cancer, selective estrogen receptor modulator (SERM) therapy and surgical interventions may be options to consider. The Breast Cancer Prevention Trial demonstrated the efficacy of tamoxifen as a preventive agent. This landmark trial showed that for high-risk women older than 35, 5 years of tamoxifen therapy can reduce the incidence of invasive breast cancer by nearly 50%.²⁶

Women with the BRCA 1 or 2 mutation—all of whom should be offered genetic counseling—were included in the study. Tamoxifen reduced the incidence of breast cancer in BRCA 2 carriers by 62%, the researchers found, but did not reduce risk in carriers of the BRCA 1 gene. This is likely due to the high prevalence of estrogen receptor-negative breast cancers among BRCA 1 carriers.²⁶

More recently, the Study of Tamoxifen and Raloxifene (STAR) trial compared the efficacy of tamoxifen and raloxifene, a second-generation SERM, in high-risk postmenopausal women ages 35 and older. The drugs were found to be equally effective in reducing the risk of invasive breast cancer, but raloxifene had a better side effect profile, with a lower incidence of thromboembolism and cataracts. ²⁷

What the guidelines call for. In 2003, the USPSTF recommended that clinicians discuss chemoprevention with women at high risk for breast cancer and low risk for adverse effects of SERMs.²⁸

The most recent update to the NCCN breast cancer risk reduction guidelines recommends that clinicians offer tamoxifen to premenopausal women with a 5-year projected breast cancer risk ≥1.7% and offer tamoxifen or raloxifene to high-risk postmenopausal women.²⁹ It is worth noting, however, that SERMs can have significant adverse effects, including venous thromboembolism, stroke, cataracts, uterine malignancy, and hot flashes, while lifestyle modifications and the avoidance of HRT have few, if any, negative effects.

CASE After consultation with a genetic counselor, Carrie underwent testing for both the BRCA 1 and BRCA 2 mutations. She tested negative for both. She declined chemoprevention and prophylactic surgery, opting for enhanced screening with yearly mammography and MRI and lifestyle modification instead.

When a mass is found

For women ages 30 or older with palpable masses or solid masses ≥2 cm found on imaging, core needle biopsy is recommended.^30,31 Biopsy is indicated for women younger than 30 as well, if the mass is >2 cm or imaging is suspicious. In general, a needle biopsy read as benign is considered adequate for diagnostic purposes only if the lesion appeared benign on imaging.

For lesions shown to be cystic on imaging, recommendations for follow-up or additional testing are based on the characteristics of the cyst. For simple cysts, 2- to 4-month follow up for stability, followed by routine screening, is adequate.²¹ Additional evaluation of complex cysts is indicated, including aspiration for complicated cysts and biopsy for complex cysts. After aspiration, surgical excision of bloody aspirates or persistent masses is recommended.^30,31

Staging using the TNM system
The TNM (tumor, node, metastases) classification system is used for the staging of breast cancer:

• T refers to the tumor type, size, and extent of local involvement
• N describes regional lymph node involvement
• M refers to distant metastases.

The TNM classifications are also grouped by stage (I through IV).,

Lumpectomy and sentinel node mapping with excision is the preferred method for staging of early-stage breast cancer without palpable lymphadenopathy—provided that the surgical team has documented experience with sentinel node biopsy.³² Sentinel node biopsy is preferred because of its safety, low (<10%) false negative rate, and decreased morbidity compared with full axillary dissection, although dissection is recommended for patients with more advanced cancer or a positive sentinel node.³² The comparative effects of sentinel node biopsy vs axillary node dissection on tumor recurrence and patient survival are not known.³³

Testing for tumor markers such as estrogen and progesterone receptors and human epidermal growth factor receptor 2 (HER2) expression status in biopsy-proven breast cancer is now the standard of care. Seventy percent of breast cancers are estrogen receptor-positive, with increasing frequency associated with older age.³⁴ Estrogen/progesterone receptor positivity is associated with a more favorable outcome, and multiple hormonal therapies can be aimed at these receptors.³⁴ While HER2 overexpression—which occurs in 15% to 30% of newly diagnosed breast cancers³⁵—is associated with more aggressive tumors, women with this type of tumor cell can benefit from trastuzumab, an anti-HER2 drug.³⁶

Key factors that affect prognosis

Important factors affecting prognosis and treatment of localized breast cancer are tumor size, age and menopausal status, tumor expression of hormone receptors and/ or the HER2 protein, as well as the status of the draining axillary nodes. Factors that predict a greater chance of recurrence include the spread of disease to axillary nodes, larger tumor size, invasive histology, inflammatory pathology, lack of estrogen/progesterone receptors, and age <50 years or premenopausal status.

Treatment options include surgical resection, radiation, and systemic adjuvant therapy in the form of chemotherapy, endocrine therapy, or anti-HER2 monoclonal antibodies.³⁷ (For more on treatment, see “Surgery, radiation, and systemic therapy: Making the most of what’s in our arsenal” at jfponline.com.)

Don’t overlook quality-of-life issues
Follow-up of breast cancer patients should go beyond treatment and work-up for recurrence and metastatic disease to focus on health and lifestyle issues, such as stress reduction, mood, smoking cessation, diet and exercise, treatment of hot flashes, sexual dysfunction, and bone health. A recent study found both reduced recurrence and increased survival in women receiving psychological interventions to improve quality-of-life measures after an 11-year follow-up.³⁸

Refer women to targeted Web sites such as the National Breast Cancer Awareness Month organization (http://www.nbcam.org/), the National Breast Cancer Foundation (http://community.nationalbreastcancer.org/), and the Susan G. Komen Breast Cancer Foundation (http://ww5.komen.org/). Offer treatment for bothersome symptoms. Hot flashes and depression, for example, often related to endocrine therapy, can be treated with selective serotonin reuptake inhibitors (SSRIs). That said, some SSRIs decrease the active metabolite of tamoxifen by inhibiting CYP2D6 enzyme and must, therefore, be used with caution. However, venlafaxine and citalopram are less likely to alter tamoxifen metabolism than other SSRIs.³⁹

CASE When Carrie was 47, she had an abnormal MRI of the left breast. Core needle biopsy and pathology of the lesion revealed an estrogen and progesterone receptor-positive tumor that was negative for HER2 overexpression. She underwent lumpectomy, which revealed a 1.5 cm tumor, followed by a negative sentinel node biopsy, and was diagnosed with stage I (T1N0M0) breast cancer. Carrie had radiation after surgery; she did not require chemotherapy, but was told to take tamoxifen for 5 years. This adjuvant endocrine therapy led to hot flashes and depression, both of which were successfully treated with venlafaxine. Carrie is currently cancer-free and participates in a breast cancer survivor program that includes regular visits with her primary physician and her oncologist.

CORRESPONDENCE Denise Sur, MD, 1920 Colorado Avenue, Santa Monica, CA 90404; dsur@mednet.ucla.edu 

Late last year, the US Preventive Services Task Force (USPSTF) sparked a nationwide controversy when it announced that it was recommending against routine screening mammography for women younger than age 50.¹ Indeed, that’s a recommendation that many other organizations, including the American Cancer Society (ACS),² the American College of Obstetricians and Gynecologists (ACOG),³ and the National Comprehensive Cancer Network (NCCN),⁴ disagree with. But the age at which women should begin routine mammography isn’t the only controversial question. Experts disagree on the benefits of breast self-examination, the optimal frequency of clinical breast exams, and the use of digital mammography—among other issues. This evidence-based review can help you cut through the confusion.

CASE Carrie, a 39-year-old woman who has never been pregnant, comes in for an annual Pap smear and gynecologic exam. She has a negative past medical history, but a positive family history for breast cancer—both her mother and 1 of her sisters had the disease. How would you assess Carrie’s risk of breast cancer, and what preventive measures would you recommend?

Use this predictive model to pinpoint your patient’s risk

When making decisions regarding primary prevention of and screening for breast cancer, an accurate assessment of risk is critical. Many predictive models have been developed with that in mind. The most widely studied, the Gail model, incorporates a number of important risk factors (TABLE 1), including age; race; family history; reproductive factors such as age of menarche, menopause, and first childbirth; and previous history of breast biopsy and atypical findings, to calculate a woman’s 5-year risk.⁵

A risk calculator (the Breast Cancer Risk Assessment Tool) based on the Gail model is available on the National Cancer Institute’s Web site, at http://www.cancer.gov/bcrisktool. Generally, a score ≥1.66%,⁵ which indicates that a patient has at least a 1.66% chance of developing breast cancer over the next 5 years, is considered high risk.^6,7

CASE Carrie’s 2 first-degree relatives affected by breast cancer and her nulliparous status place her at increased risk. Further questioning reveals a particularly strong family history, as both relatives were diagnosed before the age of 50 (her mom at 45 years of age and her sister, at 39). Carrie’s 5-year risk is 1.8%.

TABLE 1
Risk factors for breast cancer^5,29

All women can benefit from these preventive measures

As primary care physicians, we have a responsibility to stress lifestyle modification as the mainstay of breast cancer prevention. Whether or not a woman is at high risk, advise her that maintaining a normal weight, exercising vigorously, limiting alcohol consumption, and breastfeeding are evidence-based methods of primary prevention. Diets low in fat and high in fiber may be associated with a lower risk of invasive breast cancer, but there is no conclusive evidence to support specific dietary interventions to reduce the risk.^8-11 Nor has a link between active or passive smoking, antioxidants, or fruit and vegetable intake been firmly established.¹²

There is a clear association between prolonged estrogen exposure and breast cancer, however. Many reproductive factors, such as early menarche, late menopause, later age at time of first full-term pregnancy, and nulliparity, increase a woman’s exposure to endogenous estrogen—and her risk of developing breast cancer.^12,13

Exposure to exogenous estrogen is also linked to the development of breast cancer. In 2002, the Women’s Health Initiative (WHI) was stopped early after a report was released stating that the risks of hormone replacement therapy (HRT)—a higher incidence of cardiovascular events, stroke, and venous thromboembolism, as well as breast cancer—outweighed the benefits.¹⁴ Subsequent analyses have found a relationship between the declining incidence of breast cancer and the marked decrease in HRT use prompted by the WHI report. While causality has not been firmly established, multiple studies strongly suggest it.^15,16

The association between oral contraceptives (OCs) and breast cancer is more controversial. Some studies have found an increased breast cancer risk among OC users, but both the relative risk and absolute risk were found to be very small and to dissipate 10 years after stopping OC use. More recent studies with newer formulations containing lower doses of estrogen have failed to show an increased risk.⁸

Breast cancer screening: The parameters have changed

Various organizations have published guidelines for breast cancer screening (TABLE 2), and all are somewhat different. Here’s what you need to know.

Breast self-examination (BSE), which women were previously advised to perform monthly, has not been shown to improve mortality in any age group, and is no longer routinely recommended.¹⁷ While both the USPSTF and the Canadian Task Force on Preventive Health Care recommend against teaching women BSE, the ACS, ACOG, and NCCN encourage self-examination—particularly among women older than 40 years.^1-4,17,18

Clinical breast examination has an average sensitivity of 50% and detects approximately 5% of mammographically occult cancers.¹⁹ It is still not clear whether clinical breast exams save lives, however—a finding that is reflected in the USPSTF’s “I” (insufficient evidence to assess the benefits and harms) recommendation.¹ Other consensus guidelines still recommend clinical breast examination, albeit at varying frequencies.

Screening mammography decreases mortality rates by anywhere from 28% to 65%, depending on the statistical model used.²⁰ The benefit is greatest in women between the ages of 50 and 69 years, however, and most groups agree that mammography every 1 to 2 years is advisable for this age group. (There is limited data on the value of mammography for women 70 years of age and older, and no consensus on the age at which to stop screening.^1,21) But because the mortality benefit from screening mammography is lower for women aged 40 to 49, guidelines for this age group are more controversial.

Mammography’s sensitivity is affected by a variety of factors, including age and menopausal status, prior breast surgery or radiation, breast density, and the experience of the radiologist. Women in their 40s have denser breast tissue than older women, making mammography less sensitive for this age group. Because of that, and because the overall incidence of breast cancer is lower for women younger than 50, some argue that screening mammography for women between the ages of 40 and 49 years leads to unacceptably high false-positive rates (9.8% annually²²) and that the harm associated with mammography may outweigh the benefit. Others counter that tumors in younger women tend to be more aggressive and faster growing, making early detection even more critical than for older women.

What should you advise women in this age group? You might point out that the USPSTF recommends against routine screening, but indicates that the decision to begin (or defer) routine mammography before age 50 should be individualized, based on the needs and values of each patient.¹

Digital mammography. A recent study of more than 43,000 women demonstrated that digital mammography is more accurate than film—but only for certain groups: These include women <50 years of age, women with dense breasts, and pre- and perimenopausal women. ²³ Because it is still not clear whether the increased accuracy will translate into a mortality benefit, more research is needed before digital mammography is widely adopted. The USPSTF maintains that there is insufficient evidence to assess the benefits and harms of using either digital mammography or magnetic resonance imaging (MRI) rather than film mammography to screen for breast cancer.¹

MRI. In 2007, the ACS published guidelines on the use of MRI as an adjunct to mammography for breast cancer screening in high-risk women.²⁴ According to ACS guidelines, screening MRI should be offered to patients with a known BRCA 1 or 2 mutation (5%-10% of all breast cancers are associated with a mutation in the BRCA 1 or BRCA 2 gene, which is transmitted in an autosomal dominant pattern⁶). It also should be offered to those with a strong family history, or a lifetime risk of developing breast cancer that is >20% to 25%. And finally, MRI should be offered to women who had chest wall radiation when they were between the ages of 10 and 30 years—another significant risk factor for breast cancer—and those with other genetic syndromes that increase their lifetime risk of breast cancer.²⁴

Evidence is insufficient for or against MRI screening for women with a personal history of breast cancer, atypical hyperplasia, or lobular carcinoma in situ, however, and neither breast ultrasound (which is generally used diagnostically, not for screening purposes) nor MRI has been shown to be helpful as a screening tool in women with <15% lifetime risk of developing breast cancer.^24,25

TABLE 2
Guidelines for breast cancer screening for women with average risk

When to consider chemoprevention

For women like Carrie, who are at high risk of developing breast cancer, selective estrogen receptor modulator (SERM) therapy and surgical interventions may be options to consider. The Breast Cancer Prevention Trial demonstrated the efficacy of tamoxifen as a preventive agent. This landmark trial showed that for high-risk women older than 35, 5 years of tamoxifen therapy can reduce the incidence of invasive breast cancer by nearly 50%.²⁶

Women with the BRCA 1 or 2 mutation—all of whom should be offered genetic counseling—were included in the study. Tamoxifen reduced the incidence of breast cancer in BRCA 2 carriers by 62%, the researchers found, but did not reduce risk in carriers of the BRCA 1 gene. This is likely due to the high prevalence of estrogen receptor-negative breast cancers among BRCA 1 carriers.²⁶

More recently, the Study of Tamoxifen and Raloxifene (STAR) trial compared the efficacy of tamoxifen and raloxifene, a second-generation SERM, in high-risk postmenopausal women ages 35 and older. The drugs were found to be equally effective in reducing the risk of invasive breast cancer, but raloxifene had a better side effect profile, with a lower incidence of thromboembolism and cataracts. ²⁷

What the guidelines call for. In 2003, the USPSTF recommended that clinicians discuss chemoprevention with women at high risk for breast cancer and low risk for adverse effects of SERMs.²⁸

The most recent update to the NCCN breast cancer risk reduction guidelines recommends that clinicians offer tamoxifen to premenopausal women with a 5-year projected breast cancer risk ≥1.7% and offer tamoxifen or raloxifene to high-risk postmenopausal women.²⁹ It is worth noting, however, that SERMs can have significant adverse effects, including venous thromboembolism, stroke, cataracts, uterine malignancy, and hot flashes, while lifestyle modifications and the avoidance of HRT have few, if any, negative effects.

CASE After consultation with a genetic counselor, Carrie underwent testing for both the BRCA 1 and BRCA 2 mutations. She tested negative for both. She declined chemoprevention and prophylactic surgery, opting for enhanced screening with yearly mammography and MRI and lifestyle modification instead.

When a mass is found

For women ages 30 or older with palpable masses or solid masses ≥2 cm found on imaging, core needle biopsy is recommended.^30,31 Biopsy is indicated for women younger than 30 as well, if the mass is >2 cm or imaging is suspicious. In general, a needle biopsy read as benign is considered adequate for diagnostic purposes only if the lesion appeared benign on imaging.

For lesions shown to be cystic on imaging, recommendations for follow-up or additional testing are based on the characteristics of the cyst. For simple cysts, 2- to 4-month follow up for stability, followed by routine screening, is adequate.²¹ Additional evaluation of complex cysts is indicated, including aspiration for complicated cysts and biopsy for complex cysts. After aspiration, surgical excision of bloody aspirates or persistent masses is recommended.^30,31

Staging using the TNM system
The TNM (tumor, node, metastases) classification system is used for the staging of breast cancer:

• T refers to the tumor type, size, and extent of local involvement
• N describes regional lymph node involvement
• M refers to distant metastases.

The TNM classifications are also grouped by stage (I through IV).,

Lumpectomy and sentinel node mapping with excision is the preferred method for staging of early-stage breast cancer without palpable lymphadenopathy—provided that the surgical team has documented experience with sentinel node biopsy.³² Sentinel node biopsy is preferred because of its safety, low (<10%) false negative rate, and decreased morbidity compared with full axillary dissection, although dissection is recommended for patients with more advanced cancer or a positive sentinel node.³² The comparative effects of sentinel node biopsy vs axillary node dissection on tumor recurrence and patient survival are not known.³³

Testing for tumor markers such as estrogen and progesterone receptors and human epidermal growth factor receptor 2 (HER2) expression status in biopsy-proven breast cancer is now the standard of care. Seventy percent of breast cancers are estrogen receptor-positive, with increasing frequency associated with older age.³⁴ Estrogen/progesterone receptor positivity is associated with a more favorable outcome, and multiple hormonal therapies can be aimed at these receptors.³⁴ While HER2 overexpression—which occurs in 15% to 30% of newly diagnosed breast cancers³⁵—is associated with more aggressive tumors, women with this type of tumor cell can benefit from trastuzumab, an anti-HER2 drug.³⁶

Key factors that affect prognosis

Important factors affecting prognosis and treatment of localized breast cancer are tumor size, age and menopausal status, tumor expression of hormone receptors and/ or the HER2 protein, as well as the status of the draining axillary nodes. Factors that predict a greater chance of recurrence include the spread of disease to axillary nodes, larger tumor size, invasive histology, inflammatory pathology, lack of estrogen/progesterone receptors, and age <50 years or premenopausal status.

Treatment options include surgical resection, radiation, and systemic adjuvant therapy in the form of chemotherapy, endocrine therapy, or anti-HER2 monoclonal antibodies.³⁷ (For more on treatment, see “Surgery, radiation, and systemic therapy: Making the most of what’s in our arsenal” at jfponline.com.)

Don’t overlook quality-of-life issues
Follow-up of breast cancer patients should go beyond treatment and work-up for recurrence and metastatic disease to focus on health and lifestyle issues, such as stress reduction, mood, smoking cessation, diet and exercise, treatment of hot flashes, sexual dysfunction, and bone health. A recent study found both reduced recurrence and increased survival in women receiving psychological interventions to improve quality-of-life measures after an 11-year follow-up.³⁸

Refer women to targeted Web sites such as the National Breast Cancer Awareness Month organization (http://www.nbcam.org/), the National Breast Cancer Foundation (http://community.nationalbreastcancer.org/), and the Susan G. Komen Breast Cancer Foundation (http://ww5.komen.org/). Offer treatment for bothersome symptoms. Hot flashes and depression, for example, often related to endocrine therapy, can be treated with selective serotonin reuptake inhibitors (SSRIs). That said, some SSRIs decrease the active metabolite of tamoxifen by inhibiting CYP2D6 enzyme and must, therefore, be used with caution. However, venlafaxine and citalopram are less likely to alter tamoxifen metabolism than other SSRIs.³⁹

CASE When Carrie was 47, she had an abnormal MRI of the left breast. Core needle biopsy and pathology of the lesion revealed an estrogen and progesterone receptor-positive tumor that was negative for HER2 overexpression. She underwent lumpectomy, which revealed a 1.5 cm tumor, followed by a negative sentinel node biopsy, and was diagnosed with stage I (T1N0M0) breast cancer. Carrie had radiation after surgery; she did not require chemotherapy, but was told to take tamoxifen for 5 years. This adjuvant endocrine therapy led to hot flashes and depression, both of which were successfully treated with venlafaxine. Carrie is currently cancer-free and participates in a breast cancer survivor program that includes regular visits with her primary physician and her oncologist.

CORRESPONDENCE Denise Sur, MD, 1920 Colorado Avenue, Santa Monica, CA 90404; dsur@mednet.ucla.edu 

Breast tenderness is a common side effect of postmenopausal hormone therapy (HT); generally, it is dose-dependent. In this study by Crandall and colleagues, investigators assessed self-reported breast tenderness at the beginning of the WHI and after 12 months of HT, exploring any association between that tenderness and the risk of breast cancer. Here is what they found:

• Among women who reported no breast tenderness at study entry, the incidence of breast tenderness after 12 months was three times higher in those assigned to HT than in those assigned to placebo (36.1% vs 11.8%; P <.001).
• Women who reported the onset of breast tenderness after starting HT were older and more likely to be black or Hispanic than were women who did not.
• More than 75% of women who reported new breast tenderness (most often rated as mild) had been assigned to HT.
• Women taking HT who reported new breast tenderness had a risk of breast cancer 48% higher than those who did not report this complaint (P=.02).
• New-onset breast tenderness in women assigned to the placebo group was not associated with an elevated risk of breast cancer.

Does breast tenderness reflect an increase in cell proliferation?

Earlier studies have linked breast tenderness in women taking CEE plus MPA to high mammographic density, an independent risk factor for breast cancer. They have also established a link between estrogen-progestin therapy and breast cell proliferation. Therefore, as Crandall and colleagues observe, “breast discomfort may be a clinical manifestation of increased proliferation that is manifest radiographically as increased breast density.”

Keep in mind that the original WHI estrogen-progestin trial demonstrated that CEE plus MPA is associated with eight additional cases of breast cancer per 10,000 woman-years—a modest increase in risk. Although the study by Crandall and colleagues suggests that new-onset breast tenderness further increases the risk of breast cancer among users of estrogen-progestin therapy, the absolute magnitude of this increased risk is modest.

New-onset breast tenderness has a sensitivity and specificity similar to those of the Gail model for predicting the risk of invasive breast cancer. In this study, based on a mean follow-up of 5.6 years, the sensitivity and specificity of new-onset breast tenderness were 41% and 64%, respectively, and the positive predictive value was 2.7%. In comparison, using a threshold risk of breast cancer of 1.67% over 5 years, the Gail model has sensitivity, specificity, and a positive predictive value of 44%, 66%, and 6.6%, respectively.

Breast tenderness is a common side effect of postmenopausal hormone therapy (HT); generally, it is dose-dependent. In this study by Crandall and colleagues, investigators assessed self-reported breast tenderness at the beginning of the WHI and after 12 months of HT, exploring any association between that tenderness and the risk of breast cancer. Here is what they found:

• Among women who reported no breast tenderness at study entry, the incidence of breast tenderness after 12 months was three times higher in those assigned to HT than in those assigned to placebo (36.1% vs 11.8%; P <.001).
• Women who reported the onset of breast tenderness after starting HT were older and more likely to be black or Hispanic than were women who did not.
• More than 75% of women who reported new breast tenderness (most often rated as mild) had been assigned to HT.
• Women taking HT who reported new breast tenderness had a risk of breast cancer 48% higher than those who did not report this complaint (P=.02).
• New-onset breast tenderness in women assigned to the placebo group was not associated with an elevated risk of breast cancer.

Does breast tenderness reflect an increase in cell proliferation?

Earlier studies have linked breast tenderness in women taking CEE plus MPA to high mammographic density, an independent risk factor for breast cancer. They have also established a link between estrogen-progestin therapy and breast cell proliferation. Therefore, as Crandall and colleagues observe, “breast discomfort may be a clinical manifestation of increased proliferation that is manifest radiographically as increased breast density.”

Keep in mind that the original WHI estrogen-progestin trial demonstrated that CEE plus MPA is associated with eight additional cases of breast cancer per 10,000 woman-years—a modest increase in risk. Although the study by Crandall and colleagues suggests that new-onset breast tenderness further increases the risk of breast cancer among users of estrogen-progestin therapy, the absolute magnitude of this increased risk is modest.

New-onset breast tenderness has a sensitivity and specificity similar to those of the Gail model for predicting the risk of invasive breast cancer. In this study, based on a mean follow-up of 5.6 years, the sensitivity and specificity of new-onset breast tenderness were 41% and 64%, respectively, and the positive predictive value was 2.7%. In comparison, using a threshold risk of breast cancer of 1.67% over 5 years, the Gail model has sensitivity, specificity, and a positive predictive value of 44%, 66%, and 6.6%, respectively.

Breast tenderness is a common side effect of postmenopausal hormone therapy (HT); generally, it is dose-dependent. In this study by Crandall and colleagues, investigators assessed self-reported breast tenderness at the beginning of the WHI and after 12 months of HT, exploring any association between that tenderness and the risk of breast cancer. Here is what they found:

• Among women who reported no breast tenderness at study entry, the incidence of breast tenderness after 12 months was three times higher in those assigned to HT than in those assigned to placebo (36.1% vs 11.8%; P <.001).
• Women who reported the onset of breast tenderness after starting HT were older and more likely to be black or Hispanic than were women who did not.
• More than 75% of women who reported new breast tenderness (most often rated as mild) had been assigned to HT.
• Women taking HT who reported new breast tenderness had a risk of breast cancer 48% higher than those who did not report this complaint (P=.02).
• New-onset breast tenderness in women assigned to the placebo group was not associated with an elevated risk of breast cancer.

Does breast tenderness reflect an increase in cell proliferation?

Earlier studies have linked breast tenderness in women taking CEE plus MPA to high mammographic density, an independent risk factor for breast cancer. They have also established a link between estrogen-progestin therapy and breast cell proliferation. Therefore, as Crandall and colleagues observe, “breast discomfort may be a clinical manifestation of increased proliferation that is manifest radiographically as increased breast density.”

Keep in mind that the original WHI estrogen-progestin trial demonstrated that CEE plus MPA is associated with eight additional cases of breast cancer per 10,000 woman-years—a modest increase in risk. Although the study by Crandall and colleagues suggests that new-onset breast tenderness further increases the risk of breast cancer among users of estrogen-progestin therapy, the absolute magnitude of this increased risk is modest.

New-onset breast tenderness has a sensitivity and specificity similar to those of the Gail model for predicting the risk of invasive breast cancer. In this study, based on a mean follow-up of 5.6 years, the sensitivity and specificity of new-onset breast tenderness were 41% and 64%, respectively, and the positive predictive value was 2.7%. In comparison, using a threshold risk of breast cancer of 1.67% over 5 years, the Gail model has sensitivity, specificity, and a positive predictive value of 44%, 66%, and 6.6%, respectively.

Some clinicians were reconsidering the need for an annual mammogram even before the US Preventive Services Task Force (USPSTF) issued new guidelines late last year.¹

Andrew M. Kaunitz, MD, is one of those clinicians. In an editorial in the December issue of OBG Management, he was bold enough to declare: “My plan is to be more acquiescent when a woman says ‘No’ to an annual mammogram.”²

Among the evidence he cited to justify that acquiescence was a recent article in the Journal of the American Medical Association that expressed concern about the high number of early cancers—including ductal carcinoma in situ—that are detected by mammography and treated even though many are unlikely to progress or ever become clinically significant.³ This phenomenon—termed “over-diagnosis”—is one of the risks of breast cancer screening.

Dr. Kaunitz is professor and associate chairman of obstetrics and gynecology at the University of Florida College of Medicine–Jacksonville. He also serves on the OBG Management Board of Editors.

Although the USPSTF is the only official body to revise its recommendations on breast cancer screening so far, more changes seem likely. This article aims to sift through the static on the airwaves of late and offer concrete recommendations for practice. In the process, it addresses seven questions:

• How did USPSTF guidelines change?
• Why did they change?
• Why did the changes attract so much attention?
• What is ACOG’s position?
• What do thought leaders make of the new guidelines?
• Are the USPSTF recommendations likely to affect insurance coverage for mammography?
• What should you tell your patients about breast cancer screening?

1. How did USPSTF guidelines change?

In an article published November 16, the USPSTF made a number of revisions to earlier breast cancer screening guidelines for women at average risk of the disease:

Approximately 39 million women undergo mammography each year in the United States, costing the health-care system more than $5 billion.

• Routine screening mammography is no longer recommended in women 40 to 49 years old. Rather, the decision about when to begin regular screening should be individualized and should “take into account patient context, including the patient’s values regarding specific benefits and harms” (Grade C recommendation).
• Screening mammography in women 50 to 74 years old should be biennial rather than annual (Grade B recommendation).
• Breast self-examination (BSE) is not recommended for any age group (Grade D recommendation).¹

2. Why did the USPSTF guidelines change?

The changes were based on new data and analysis in the following areas:

• Mortality among women 40 to 49 years old. Although mammography screening reduces breast cancer mortality by 15% in this age group, the USPSTF concluded that “there is moderate certainty that the net benefit is small” in this population.^1,4
• The effectiveness of BSE in decreasing breast cancer mortality among women of any age. Studies of BSE published since 2002 found no significant differences in breast cancer mortality between women who perform BSE and those who don’t.⁴
• The magnitude of harms of screening with mammography. Mammography screening in women 40 to 49 years old involves a significant risk of harms.⁴ Although the USPSTF observed that the benefits of mammography in women 40 to 49 years old appear to be equivalent to the benefits of mammography among women 50 to 59 years old, it concluded that the harms outweigh benefits in the younger women.

Harms cited by the USPSTF include:

• radiation exposure
• pain during the procedure
• anxiety and distress
• an increased rate of false-positive results
• greater need for additional imaging and biopsies.⁴

The USPSTF conceded that the radiation exposure from a mammogram is minimal, but questioned whether cumulative exposure in young women might be problematic. It also noted that “many women experience pain during the procedure (range, 1% to 77%), but few would consider this a deterrent from future screening.”⁴

As for false-positive results, the group observed: “Data from the [Breast Cancer Screening Consortium (BCSC)] for regularly screened women…indicate that false-positive mammography results are common in all age groups but are most common among women aged 40 to 49 years (97.8 per 1,000 women per screening round).”⁴

“The BCSC results indicate that for every case of invasive breast cancer detected by mammography screening in women aged 40 to 49 years, 556 women have mammography, 47 have additional imaging, and five have biopsies.”⁴

It is the significant rate of false positives that creates the need for additional screening, diagnostic imaging, and biopsy. These additional imaging and invasive procedures increase anxiety and distress among many women. The USPSTF concluded that these harms outweighed the benefits of mammography screening in women 40 to 49 years old.

3. Why have the guidelines captured so much media attention?

Most of the controversy that has arisen since publication of the new guidelines has centered on the recommendation against screening mammography in women 40 to 49 years old. A number of media outlets have highlighted women whose breast cancer was detected by screening mammography when they were in their 40s, and many survivors with a similar history have spoken out against the new recommendations.

In addition, the American Cancer Society (ACS), the American College of Radiology, Susan G. Komen for the Cure, and other groups have publicly opposed the new guidelines. (See “Among professional organizations, a resounding chorus of disagreement”)

4. What is ACOG’s position on the new recommendations?

The American College of Obstetricians and Gynecologists (ACOG) was quick to weigh in on the new USPSTF guidelines, emphasizing that the College’s recommendations have not changed. They include:

• screening mammography every 1 to 2 years for women 40 to 49 years old
• screening mammography every year for women 50 years and older
• BSE for all women.

ACOG did note, however, that “the College is continuing to evaluate in detail the new USPSTF recommendations and the new evidence considered by the USPSTF.”⁵

5. What do thought leaders make of the USPSTF changes?

Although the USPSTF guidelines sparked a firestorm of media coverage, the change did not come as a shock to leaders in the ObGyn specialty.

Legitimate concerns about screening mammography have increasingly been raised by experts in the field.

ANDREW M. KAUNITZ, MD “I was not surprised,” said Dr. Kaunitz. “As I pointed out in my editorial in OBG Management, legitimate concerns about screening mammography have increasingly been raised by experts in the field.² Proposals to stop routinely screening women in their 40s were made earlier in this decade, but were met with major pushback from the ACS, breast cancer advocacy organizations, and medical specialty groups. These same groups are now pushing back against the new USPSTF guidelines,” he added.

Robert L. Barbieri, MD, was not taken aback by the guidelines themselves, but he was surprised by the manner and timing of their release. Dr. Barbieri is Kate Macy Ladd professor of obstetrics, gynecology, and reproductive biology at Harvard Medical School and chief of obstetrics and gynecology at Brigham and Women’s Hospital in Boston. He serves as editor-in-chief of OBG Management.

“I was surprised that the USPSTF did not weigh the potential impact of its analysis on the key stakeholders: patients, disease-based coalitions such as the American Cancer Society and Susan G. Komen for the Cure, and professional societies such as the American College of Radiology and ACOG,” he said. “If I were supervising the process, I would have asked for a comment period before releasing the report. I would have included the comments from key stakeholders in an appendix to the report.”

Are other organizations—besides the USPSTF—likely to change their recommendations for mammography screening in the near future? In the case of ACOG, Dr. Barbieri doesn’t think so.

“I don’t think ACOG will change the age at which to initiate screening,” he said. “I believe it will stick to its recommendation to start screening at 40 and continue every 1 to 2 years from 40 to 50 years of age. However, I could see ACOG becoming a bit more flexible on the question of whether screening should take place at 1- or 2-year intervals after age 50.”

Dr. Kaunitz sees things differently.

“It seems possible that, going forward, the College will give Fellows and their patients permission to implement the new guidelines without mandating their implementation. For example, if women in their 40s wish to defer screening, that would be OK, as would biennial screening for women in their 50s and 60s.”

6. Are the USPSTF recommendations likely to affect insurance coverage?

In a press release issued soon after the new guidelines were published, US Health and Human Services Secretary Kathleen Sebelius addressed Americans directly to reaffirm her support for mammography in women 40 to 49 years old: “There is no question that the US Preventive Services Task Force recommendations have caused a great deal of confusion and worry among women and their families,” her statement read.⁶ She made it clear that the new recommendations are unlikely to affect federal coverage of mammography.

“The US Preventive Services Task Force is an outside independent panel of doctors and scientists who make recommendations. They do not set federal policy and they don’t determine what services are covered by the federal government,” she said.⁶

But Dr. Barbieri thinks some changes in insurance coverage are inevitable.

“Any claims that the new guidelines do not represent a major change would be disingenuous,” he said. Because the USPSTF rated its recommendation against mammography for women 40 to 49 years old as grade ‘C,’ that change in guidelines is likely to trigger at least some change in coverage.

“In reality, the ‘C’ rating will require many insurance companies—by their own rule—to stop reimbursing for this screening test,” he said. “The ‘C’ rating means that the test has little benefit.”

ACOG also deems it likely that insurance coverage may be affected for some women.

“Fellows should be aware that the new USPSTF recommendations against routine screening mammography for women aged 40–49 (a grade C recommendation) has implications for insurance coverage, as some insurers will cover only preventive services rated as an ‘A’ or a ‘B’ by the USPSTF. Fellows should counsel their patients that insurance coverage for ‘routine screening’ mammography may become variable and that patients should address this question with their insurers. These recommendations do not apply to high-risk women or patients with clinical findings, and they should be managed accordingly.”⁵

7. What should you tell your patients?

With all the media attention devoted to the change in guidelines, it’s little surprise that patients are asking questions.

“Patients are aware of the USPSTF report,” said Dr. Barbieri. “They are largely ignoring the recommendations and sticking with annual mammograms.”

“I think, as always, women are looking to their ObGyn for guidance,” added Dr. Kaunitz.

So what are these clinicians telling patients about mammography screening?

As he was to begin with, Dr. Kaunitz is acquiescent if patients prefer to defer mammography screening to their 50s.

“Because it seems that insurance coverage, over the short term, is unlikely to restrict current access to mammograms,” said Dr. Kaunitz, “my evolving philosophy is that the new USPSTF guidelines, along with ACOG and other existing guidelines, give ObGyns and their patients permission to:

• proceed or not proceed with mammograms for women in their 40s, with the decision based on issues such as patient preference, family history of breast cancer, and body mass index (BMI)
• be flexible regarding 1- to 2-year screening intervals among women in their 50s, 60s, and 70s, with the decision based on issues such as patient preference, use or non-use of estrogen-progestin hormone therapy, family history of breast cancer, and BMI.”

Dr. Barbieri believes some effort to integrate the ACOG and USPSTF recommendations is called for. “Accordingly,” he said, “I suggest the following:

I suggest actively recommending biennial mammography for women 40 to 75 years old. Offer annual mammography to women 40 to 75 years old if they prefer that option.

ROBERT L. BARBIERI, MD

• Actively recommend biennial mammography for women 40 to 75 years old. Offer annual mammography to women 40 to 75 years old if they prefer that option.
• Aggressively search for high-risk women, with high risk defined as a lifetime risk of breast cancer exceeding 15%. Among the variables contributing to high-risk status are a history of thoracic radiotherapy, a strong family history of breast cancer, and BRCA mutation. For these women, I would recommend annual mammography and biennial MRI of the breasts.
• Perform annual or biennial clinical breast exam.
• Obtain imaging for any woman who has a palpable breast lump, and resect or biopsy the lump even if that imaging is negative.”

Some clinicians were reconsidering the need for an annual mammogram even before the US Preventive Services Task Force (USPSTF) issued new guidelines late last year.¹

Andrew M. Kaunitz, MD, is one of those clinicians. In an editorial in the December issue of OBG Management, he was bold enough to declare: “My plan is to be more acquiescent when a woman says ‘No’ to an annual mammogram.”²

Among the evidence he cited to justify that acquiescence was a recent article in the Journal of the American Medical Association that expressed concern about the high number of early cancers—including ductal carcinoma in situ—that are detected by mammography and treated even though many are unlikely to progress or ever become clinically significant.³ This phenomenon—termed “over-diagnosis”—is one of the risks of breast cancer screening.

Dr. Kaunitz is professor and associate chairman of obstetrics and gynecology at the University of Florida College of Medicine–Jacksonville. He also serves on the OBG Management Board of Editors.

Although the USPSTF is the only official body to revise its recommendations on breast cancer screening so far, more changes seem likely. This article aims to sift through the static on the airwaves of late and offer concrete recommendations for practice. In the process, it addresses seven questions:

• How did USPSTF guidelines change?
• Why did they change?
• Why did the changes attract so much attention?
• What is ACOG’s position?
• What do thought leaders make of the new guidelines?
• Are the USPSTF recommendations likely to affect insurance coverage for mammography?
• What should you tell your patients about breast cancer screening?

1. How did USPSTF guidelines change?

In an article published November 16, the USPSTF made a number of revisions to earlier breast cancer screening guidelines for women at average risk of the disease:

Approximately 39 million women undergo mammography each year in the United States, costing the health-care system more than $5 billion.

• Routine screening mammography is no longer recommended in women 40 to 49 years old. Rather, the decision about when to begin regular screening should be individualized and should “take into account patient context, including the patient’s values regarding specific benefits and harms” (Grade C recommendation).
• Screening mammography in women 50 to 74 years old should be biennial rather than annual (Grade B recommendation).
• Breast self-examination (BSE) is not recommended for any age group (Grade D recommendation).¹

2. Why did the USPSTF guidelines change?

The changes were based on new data and analysis in the following areas:

• Mortality among women 40 to 49 years old. Although mammography screening reduces breast cancer mortality by 15% in this age group, the USPSTF concluded that “there is moderate certainty that the net benefit is small” in this population.^1,4
• The effectiveness of BSE in decreasing breast cancer mortality among women of any age. Studies of BSE published since 2002 found no significant differences in breast cancer mortality between women who perform BSE and those who don’t.⁴
• The magnitude of harms of screening with mammography. Mammography screening in women 40 to 49 years old involves a significant risk of harms.⁴ Although the USPSTF observed that the benefits of mammography in women 40 to 49 years old appear to be equivalent to the benefits of mammography among women 50 to 59 years old, it concluded that the harms outweigh benefits in the younger women.

Harms cited by the USPSTF include:

• radiation exposure
• pain during the procedure
• anxiety and distress
• an increased rate of false-positive results
• greater need for additional imaging and biopsies.⁴

The USPSTF conceded that the radiation exposure from a mammogram is minimal, but questioned whether cumulative exposure in young women might be problematic. It also noted that “many women experience pain during the procedure (range, 1% to 77%), but few would consider this a deterrent from future screening.”⁴

As for false-positive results, the group observed: “Data from the [Breast Cancer Screening Consortium (BCSC)] for regularly screened women…indicate that false-positive mammography results are common in all age groups but are most common among women aged 40 to 49 years (97.8 per 1,000 women per screening round).”⁴

“The BCSC results indicate that for every case of invasive breast cancer detected by mammography screening in women aged 40 to 49 years, 556 women have mammography, 47 have additional imaging, and five have biopsies.”⁴

It is the significant rate of false positives that creates the need for additional screening, diagnostic imaging, and biopsy. These additional imaging and invasive procedures increase anxiety and distress among many women. The USPSTF concluded that these harms outweighed the benefits of mammography screening in women 40 to 49 years old.

3. Why have the guidelines captured so much media attention?

Most of the controversy that has arisen since publication of the new guidelines has centered on the recommendation against screening mammography in women 40 to 49 years old. A number of media outlets have highlighted women whose breast cancer was detected by screening mammography when they were in their 40s, and many survivors with a similar history have spoken out against the new recommendations.

In addition, the American Cancer Society (ACS), the American College of Radiology, Susan G. Komen for the Cure, and other groups have publicly opposed the new guidelines. (See “Among professional organizations, a resounding chorus of disagreement”)

4. What is ACOG’s position on the new recommendations?

The American College of Obstetricians and Gynecologists (ACOG) was quick to weigh in on the new USPSTF guidelines, emphasizing that the College’s recommendations have not changed. They include:

• screening mammography every 1 to 2 years for women 40 to 49 years old
• screening mammography every year for women 50 years and older
• BSE for all women.

ACOG did note, however, that “the College is continuing to evaluate in detail the new USPSTF recommendations and the new evidence considered by the USPSTF.”⁵

5. What do thought leaders make of the USPSTF changes?

Although the USPSTF guidelines sparked a firestorm of media coverage, the change did not come as a shock to leaders in the ObGyn specialty.

Legitimate concerns about screening mammography have increasingly been raised by experts in the field.

ANDREW M. KAUNITZ, MD “I was not surprised,” said Dr. Kaunitz. “As I pointed out in my editorial in OBG Management, legitimate concerns about screening mammography have increasingly been raised by experts in the field.² Proposals to stop routinely screening women in their 40s were made earlier in this decade, but were met with major pushback from the ACS, breast cancer advocacy organizations, and medical specialty groups. These same groups are now pushing back against the new USPSTF guidelines,” he added.

Robert L. Barbieri, MD, was not taken aback by the guidelines themselves, but he was surprised by the manner and timing of their release. Dr. Barbieri is Kate Macy Ladd professor of obstetrics, gynecology, and reproductive biology at Harvard Medical School and chief of obstetrics and gynecology at Brigham and Women’s Hospital in Boston. He serves as editor-in-chief of OBG Management.

“I was surprised that the USPSTF did not weigh the potential impact of its analysis on the key stakeholders: patients, disease-based coalitions such as the American Cancer Society and Susan G. Komen for the Cure, and professional societies such as the American College of Radiology and ACOG,” he said. “If I were supervising the process, I would have asked for a comment period before releasing the report. I would have included the comments from key stakeholders in an appendix to the report.”

Are other organizations—besides the USPSTF—likely to change their recommendations for mammography screening in the near future? In the case of ACOG, Dr. Barbieri doesn’t think so.

“I don’t think ACOG will change the age at which to initiate screening,” he said. “I believe it will stick to its recommendation to start screening at 40 and continue every 1 to 2 years from 40 to 50 years of age. However, I could see ACOG becoming a bit more flexible on the question of whether screening should take place at 1- or 2-year intervals after age 50.”

Dr. Kaunitz sees things differently.

“It seems possible that, going forward, the College will give Fellows and their patients permission to implement the new guidelines without mandating their implementation. For example, if women in their 40s wish to defer screening, that would be OK, as would biennial screening for women in their 50s and 60s.”

6. Are the USPSTF recommendations likely to affect insurance coverage?

In a press release issued soon after the new guidelines were published, US Health and Human Services Secretary Kathleen Sebelius addressed Americans directly to reaffirm her support for mammography in women 40 to 49 years old: “There is no question that the US Preventive Services Task Force recommendations have caused a great deal of confusion and worry among women and their families,” her statement read.⁶ She made it clear that the new recommendations are unlikely to affect federal coverage of mammography.

“The US Preventive Services Task Force is an outside independent panel of doctors and scientists who make recommendations. They do not set federal policy and they don’t determine what services are covered by the federal government,” she said.⁶

But Dr. Barbieri thinks some changes in insurance coverage are inevitable.

“Any claims that the new guidelines do not represent a major change would be disingenuous,” he said. Because the USPSTF rated its recommendation against mammography for women 40 to 49 years old as grade ‘C,’ that change in guidelines is likely to trigger at least some change in coverage.

“In reality, the ‘C’ rating will require many insurance companies—by their own rule—to stop reimbursing for this screening test,” he said. “The ‘C’ rating means that the test has little benefit.”

ACOG also deems it likely that insurance coverage may be affected for some women.

“Fellows should be aware that the new USPSTF recommendations against routine screening mammography for women aged 40–49 (a grade C recommendation) has implications for insurance coverage, as some insurers will cover only preventive services rated as an ‘A’ or a ‘B’ by the USPSTF. Fellows should counsel their patients that insurance coverage for ‘routine screening’ mammography may become variable and that patients should address this question with their insurers. These recommendations do not apply to high-risk women or patients with clinical findings, and they should be managed accordingly.”⁵

7. What should you tell your patients?

With all the media attention devoted to the change in guidelines, it’s little surprise that patients are asking questions.

“Patients are aware of the USPSTF report,” said Dr. Barbieri. “They are largely ignoring the recommendations and sticking with annual mammograms.”

“I think, as always, women are looking to their ObGyn for guidance,” added Dr. Kaunitz.

So what are these clinicians telling patients about mammography screening?

As he was to begin with, Dr. Kaunitz is acquiescent if patients prefer to defer mammography screening to their 50s.

“Because it seems that insurance coverage, over the short term, is unlikely to restrict current access to mammograms,” said Dr. Kaunitz, “my evolving philosophy is that the new USPSTF guidelines, along with ACOG and other existing guidelines, give ObGyns and their patients permission to:

• proceed or not proceed with mammograms for women in their 40s, with the decision based on issues such as patient preference, family history of breast cancer, and body mass index (BMI)
• be flexible regarding 1- to 2-year screening intervals among women in their 50s, 60s, and 70s, with the decision based on issues such as patient preference, use or non-use of estrogen-progestin hormone therapy, family history of breast cancer, and BMI.”

Dr. Barbieri believes some effort to integrate the ACOG and USPSTF recommendations is called for. “Accordingly,” he said, “I suggest the following:

I suggest actively recommending biennial mammography for women 40 to 75 years old. Offer annual mammography to women 40 to 75 years old if they prefer that option.

ROBERT L. BARBIERI, MD

• Actively recommend biennial mammography for women 40 to 75 years old. Offer annual mammography to women 40 to 75 years old if they prefer that option.
• Aggressively search for high-risk women, with high risk defined as a lifetime risk of breast cancer exceeding 15%. Among the variables contributing to high-risk status are a history of thoracic radiotherapy, a strong family history of breast cancer, and BRCA mutation. For these women, I would recommend annual mammography and biennial MRI of the breasts.
• Perform annual or biennial clinical breast exam.
• Obtain imaging for any woman who has a palpable breast lump, and resect or biopsy the lump even if that imaging is negative.”

Some clinicians were reconsidering the need for an annual mammogram even before the US Preventive Services Task Force (USPSTF) issued new guidelines late last year.¹

Andrew M. Kaunitz, MD, is one of those clinicians. In an editorial in the December issue of OBG Management, he was bold enough to declare: “My plan is to be more acquiescent when a woman says ‘No’ to an annual mammogram.”²

Among the evidence he cited to justify that acquiescence was a recent article in the Journal of the American Medical Association that expressed concern about the high number of early cancers—including ductal carcinoma in situ—that are detected by mammography and treated even though many are unlikely to progress or ever become clinically significant.³ This phenomenon—termed “over-diagnosis”—is one of the risks of breast cancer screening.

Dr. Kaunitz is professor and associate chairman of obstetrics and gynecology at the University of Florida College of Medicine–Jacksonville. He also serves on the OBG Management Board of Editors.

Although the USPSTF is the only official body to revise its recommendations on breast cancer screening so far, more changes seem likely. This article aims to sift through the static on the airwaves of late and offer concrete recommendations for practice. In the process, it addresses seven questions:

• How did USPSTF guidelines change?
• Why did they change?
• Why did the changes attract so much attention?
• What is ACOG’s position?
• What do thought leaders make of the new guidelines?
• Are the USPSTF recommendations likely to affect insurance coverage for mammography?
• What should you tell your patients about breast cancer screening?

1. How did USPSTF guidelines change?

In an article published November 16, the USPSTF made a number of revisions to earlier breast cancer screening guidelines for women at average risk of the disease:

Approximately 39 million women undergo mammography each year in the United States, costing the health-care system more than $5 billion.

• Routine screening mammography is no longer recommended in women 40 to 49 years old. Rather, the decision about when to begin regular screening should be individualized and should “take into account patient context, including the patient’s values regarding specific benefits and harms” (Grade C recommendation).
• Screening mammography in women 50 to 74 years old should be biennial rather than annual (Grade B recommendation).
• Breast self-examination (BSE) is not recommended for any age group (Grade D recommendation).¹

2. Why did the USPSTF guidelines change?

The changes were based on new data and analysis in the following areas:

• Mortality among women 40 to 49 years old. Although mammography screening reduces breast cancer mortality by 15% in this age group, the USPSTF concluded that “there is moderate certainty that the net benefit is small” in this population.^1,4
• The effectiveness of BSE in decreasing breast cancer mortality among women of any age. Studies of BSE published since 2002 found no significant differences in breast cancer mortality between women who perform BSE and those who don’t.⁴
• The magnitude of harms of screening with mammography. Mammography screening in women 40 to 49 years old involves a significant risk of harms.⁴ Although the USPSTF observed that the benefits of mammography in women 40 to 49 years old appear to be equivalent to the benefits of mammography among women 50 to 59 years old, it concluded that the harms outweigh benefits in the younger women.

Harms cited by the USPSTF include:

• radiation exposure
• pain during the procedure
• anxiety and distress
• an increased rate of false-positive results
• greater need for additional imaging and biopsies.⁴

The USPSTF conceded that the radiation exposure from a mammogram is minimal, but questioned whether cumulative exposure in young women might be problematic. It also noted that “many women experience pain during the procedure (range, 1% to 77%), but few would consider this a deterrent from future screening.”⁴

As for false-positive results, the group observed: “Data from the [Breast Cancer Screening Consortium (BCSC)] for regularly screened women…indicate that false-positive mammography results are common in all age groups but are most common among women aged 40 to 49 years (97.8 per 1,000 women per screening round).”⁴

“The BCSC results indicate that for every case of invasive breast cancer detected by mammography screening in women aged 40 to 49 years, 556 women have mammography, 47 have additional imaging, and five have biopsies.”⁴

It is the significant rate of false positives that creates the need for additional screening, diagnostic imaging, and biopsy. These additional imaging and invasive procedures increase anxiety and distress among many women. The USPSTF concluded that these harms outweighed the benefits of mammography screening in women 40 to 49 years old.

3. Why have the guidelines captured so much media attention?

Most of the controversy that has arisen since publication of the new guidelines has centered on the recommendation against screening mammography in women 40 to 49 years old. A number of media outlets have highlighted women whose breast cancer was detected by screening mammography when they were in their 40s, and many survivors with a similar history have spoken out against the new recommendations.

In addition, the American Cancer Society (ACS), the American College of Radiology, Susan G. Komen for the Cure, and other groups have publicly opposed the new guidelines. (See “Among professional organizations, a resounding chorus of disagreement”)

4. What is ACOG’s position on the new recommendations?

The American College of Obstetricians and Gynecologists (ACOG) was quick to weigh in on the new USPSTF guidelines, emphasizing that the College’s recommendations have not changed. They include:

• screening mammography every 1 to 2 years for women 40 to 49 years old
• screening mammography every year for women 50 years and older
• BSE for all women.

ACOG did note, however, that “the College is continuing to evaluate in detail the new USPSTF recommendations and the new evidence considered by the USPSTF.”⁵

5. What do thought leaders make of the USPSTF changes?

Although the USPSTF guidelines sparked a firestorm of media coverage, the change did not come as a shock to leaders in the ObGyn specialty.

Legitimate concerns about screening mammography have increasingly been raised by experts in the field.

ANDREW M. KAUNITZ, MD “I was not surprised,” said Dr. Kaunitz. “As I pointed out in my editorial in OBG Management, legitimate concerns about screening mammography have increasingly been raised by experts in the field.² Proposals to stop routinely screening women in their 40s were made earlier in this decade, but were met with major pushback from the ACS, breast cancer advocacy organizations, and medical specialty groups. These same groups are now pushing back against the new USPSTF guidelines,” he added.

Robert L. Barbieri, MD, was not taken aback by the guidelines themselves, but he was surprised by the manner and timing of their release. Dr. Barbieri is Kate Macy Ladd professor of obstetrics, gynecology, and reproductive biology at Harvard Medical School and chief of obstetrics and gynecology at Brigham and Women’s Hospital in Boston. He serves as editor-in-chief of OBG Management.

“I was surprised that the USPSTF did not weigh the potential impact of its analysis on the key stakeholders: patients, disease-based coalitions such as the American Cancer Society and Susan G. Komen for the Cure, and professional societies such as the American College of Radiology and ACOG,” he said. “If I were supervising the process, I would have asked for a comment period before releasing the report. I would have included the comments from key stakeholders in an appendix to the report.”

Are other organizations—besides the USPSTF—likely to change their recommendations for mammography screening in the near future? In the case of ACOG, Dr. Barbieri doesn’t think so.

“I don’t think ACOG will change the age at which to initiate screening,” he said. “I believe it will stick to its recommendation to start screening at 40 and continue every 1 to 2 years from 40 to 50 years of age. However, I could see ACOG becoming a bit more flexible on the question of whether screening should take place at 1- or 2-year intervals after age 50.”

Dr. Kaunitz sees things differently.

“It seems possible that, going forward, the College will give Fellows and their patients permission to implement the new guidelines without mandating their implementation. For example, if women in their 40s wish to defer screening, that would be OK, as would biennial screening for women in their 50s and 60s.”

6. Are the USPSTF recommendations likely to affect insurance coverage?

In a press release issued soon after the new guidelines were published, US Health and Human Services Secretary Kathleen Sebelius addressed Americans directly to reaffirm her support for mammography in women 40 to 49 years old: “There is no question that the US Preventive Services Task Force recommendations have caused a great deal of confusion and worry among women and their families,” her statement read.⁶ She made it clear that the new recommendations are unlikely to affect federal coverage of mammography.

“The US Preventive Services Task Force is an outside independent panel of doctors and scientists who make recommendations. They do not set federal policy and they don’t determine what services are covered by the federal government,” she said.⁶

But Dr. Barbieri thinks some changes in insurance coverage are inevitable.

“Any claims that the new guidelines do not represent a major change would be disingenuous,” he said. Because the USPSTF rated its recommendation against mammography for women 40 to 49 years old as grade ‘C,’ that change in guidelines is likely to trigger at least some change in coverage.

“In reality, the ‘C’ rating will require many insurance companies—by their own rule—to stop reimbursing for this screening test,” he said. “The ‘C’ rating means that the test has little benefit.”

ACOG also deems it likely that insurance coverage may be affected for some women.

“Fellows should be aware that the new USPSTF recommendations against routine screening mammography for women aged 40–49 (a grade C recommendation) has implications for insurance coverage, as some insurers will cover only preventive services rated as an ‘A’ or a ‘B’ by the USPSTF. Fellows should counsel their patients that insurance coverage for ‘routine screening’ mammography may become variable and that patients should address this question with their insurers. These recommendations do not apply to high-risk women or patients with clinical findings, and they should be managed accordingly.”⁵

7. What should you tell your patients?

With all the media attention devoted to the change in guidelines, it’s little surprise that patients are asking questions.

“Patients are aware of the USPSTF report,” said Dr. Barbieri. “They are largely ignoring the recommendations and sticking with annual mammograms.”

“I think, as always, women are looking to their ObGyn for guidance,” added Dr. Kaunitz.

So what are these clinicians telling patients about mammography screening?

As he was to begin with, Dr. Kaunitz is acquiescent if patients prefer to defer mammography screening to their 50s.

“Because it seems that insurance coverage, over the short term, is unlikely to restrict current access to mammograms,” said Dr. Kaunitz, “my evolving philosophy is that the new USPSTF guidelines, along with ACOG and other existing guidelines, give ObGyns and their patients permission to:

• proceed or not proceed with mammograms for women in their 40s, with the decision based on issues such as patient preference, family history of breast cancer, and body mass index (BMI)
• be flexible regarding 1- to 2-year screening intervals among women in their 50s, 60s, and 70s, with the decision based on issues such as patient preference, use or non-use of estrogen-progestin hormone therapy, family history of breast cancer, and BMI.”

Dr. Barbieri believes some effort to integrate the ACOG and USPSTF recommendations is called for. “Accordingly,” he said, “I suggest the following:

I suggest actively recommending biennial mammography for women 40 to 75 years old. Offer annual mammography to women 40 to 75 years old if they prefer that option.

ROBERT L. BARBIERI, MD

• Actively recommend biennial mammography for women 40 to 75 years old. Offer annual mammography to women 40 to 75 years old if they prefer that option.
• Aggressively search for high-risk women, with high risk defined as a lifetime risk of breast cancer exceeding 15%. Among the variables contributing to high-risk status are a history of thoracic radiotherapy, a strong family history of breast cancer, and BRCA mutation. For these women, I would recommend annual mammography and biennial MRI of the breasts.
• Perform annual or biennial clinical breast exam.
• Obtain imaging for any woman who has a palpable breast lump, and resect or biopsy the lump even if that imaging is negative.”

Dr. Rowan Chlebowski of Harbor-UCLA's medical center discusses two studies that suggest bisphophonates can lower risk to breast cancer.

Dr. Rowan Chlebowski of Harbor-UCLA's medical center discusses two studies that suggest bisphophonates can lower risk to breast cancer.

Dr. Rowan Chlebowski of Harbor-UCLA's medical center discusses two studies that suggest bisphophonates can lower risk to breast cancer.

The author reports that he is a consultant to Eli Lilly, Pfizer, and Wyeth, and a speaker for Eli Lilly and Wyeth.

CASE 1: Premenopausal woman
at high risk of breast cancer

R. J. is a 43-year-old, nulliparous woman who reached menarche at age 11. She has undergone two breast biopsies, the most recent of which revealed ductal hyperplasia with marked atypia.

R. J.’s sister had breast cancer at 49 years of age; her mother had breast cancer at 66 years. Because of R. J.’s family history, she underwent testing for a BRCA mutation. The result was negative.

R. J. has come to your office today to find out if she can do anything to reduce her risk of breast cancer. What options can you offer?

The most common method of “prevention” of breast cancer involves early detection and assessment of abnormalities through frequent surveillance with mammography. Some women who have dense breasts, a history of breast biopsy, or other risk factors for breast cancer may benefit from intensive surveillance with both mammography and ultrasonography—and, in some cases, magnetic resonance imaging.

More aggressive options include:

• the use of a chemopreventive agent such as tamoxifen or raloxifene
• in rare cases—usually when a BRCA mutation is present—prophylactic mastectomy.

Before it is possible to determine the optimal approach for a particular woman, it is necessary to conduct an individualized assessment of her risk—that is, to estimate the probability that she will develop breast cancer over a defined period of time. Such an estimate is also useful for designing prevention trials in high-risk subsets of the population. (Prevention trials differ from therapeutic clinical trials in that asymptomatic healthy women are exposed to potentially toxic interventions for prolonged periods to reduce their risk of breast cancer.)

This article describes chemopreventive options for women at high risk, based on individualized risk assessment using the Gail model.

(Editor’s note: For additional discussion of the important role ObGyns play in the fight against breast cancer, see Editor in Chief Dr. Robert L. Barbieri’s Editorial.)

What constitutes high risk?

You can estimate the likelihood that a woman like your patient may develop breast cancer using various individual risk factors ( TABLE 1 ), but estimates for combinations of risk factors are preferable. The Gail model takes into account some nongenetic factors, such as parity and age at menarche, but also genetic factors, such as family history. The model calculates a woman’s individualized breast cancer probability and yields a numerical risk (a percentage) that she will develop invasive breast cancer over the next 5 years; it also yields an estimate of her risk of developing the malignancy over the remainder of her life.^1,2

A Gail-model 5-year estimate of 1.66% or higher denotes a high risk of developing breast cancer. That benchmark was the one employed in the Breast Cancer Prevention Trial (BCPT), conducted as part of the National Surgical Adjuvant Breast and Bowel Project (NSABP).³

TABLE 1

What are the risk factors for breast cancer?
And what degree of relative risk do they confer?

Weaknesses of the Gail model

The Gail model’s approach to estimating risk has some limitations. The model uses the number of prior breast biopsies in its assessment—but the relative risk associated with prior biopsy is smaller for women older than 50 years than it is for younger women.

Furthermore, data on which Gail bases its estimates were collected in the late 1970s and early 1980s. Since then, the increasing ease of breast histopathologic assessment—through fine-needle aspiration and outpatient core-needle biopsy—has confused the issue of just what constitutes a breast “biopsy.” (Most patients surveyed consider it to be any histologic sampling of the breast.)

As a result, the 1.66% cutoff becomes somewhat difficult to interpret in light of current practice.

Consider the following example. A 50-year-old nulliparous Caucasian woman reached menarche when she was 11 years old, has never had a biopsy, and has no first-degree relatives with breast cancer. According to the Gail model, her risk of developing breast cancer is 1.2% over the next 5 years and 10.8% in her lifetime. Therefore, she is not considered at high risk. If she were to give a history of three previous breast biopsies, however, none of them showing hyperplasia, her 5-year risk would rise to 1.8% and push her over the line into the high-risk category.

Compare her situation to that of R. J., the nulliparous woman described in Case 1. R. J. also reached menarche at 11 years, but she has had two breast biopsies (one of which showed atypical hyperplasia) and has two first-degree relatives who have had breast cancer. Her Gail score shows a 5-year risk of breast cancer of 13.5% (the norm for a 43-year-old woman is 0.8%), and a lifetime risk of 69.2%. Clearly, she has a high risk of breast cancer.

How do we improve an imperfect science?

We need to identify objective findings that are patient-specific but highly correlative with the development of breast cancer. Patient-specific biomarkers have been proposed, such as ultrasensitive measurement of the serum estradiol level in postmenopausal women. In the Multiple Outcomes of Raloxifene Evaluation, also known as the MORE trial, women who experienced the greatest reduction in the rate of breast cancer during treatment with raloxifene were a subgroup who had the highest baseline level of serum estradiol—although, overall, all patients had an estradiol level well within the postmenopausal range (≤20 pmol/L).^4,5

How tamoxifen became a chemopreventive agent

Tamoxifen inhibits mammary tumors in mice and rats and suppresses hormone-dependent breast cancer cell lines in vitro.⁶ Clinical data from the Early Breast Cancer Trialists’ Collaborative Group yielded additional motivation for prevention trials with tamoxifen: Besides reducing the rate of recurrent breast cancer, tamoxifen reduced the risk of contralateral new-onset breast cancer by 47% after 5 years of adjuvant treatment.⁷ Preclinical findings in vitro and in animal models, coupled with clinical data and evidence of tamoxifen’s favorable effects on skeleton remodeling and lipid levels, led to a series of chemoprevention trials in the United States and Europe using tamoxifen.

In the aforementioned BCPT, launched in 1992, 13,388 women 35 years and older who were deemed to be at high risk of developing breast cancer were enrolled at numerous sites throughout the United States and Canada.³ The Gail model was used to select women for the trial—only those who had a 5-year risk of 1.66% or higher were included. Participants were randomly assigned to receive tamoxifen 20 mg or placebo daily for 5 years. The trial was terminated early because of the dramatic reduction in new-onset breast cancer with tamoxifen, compared with placebo.

The overall incidence of breast cancer in the tamoxifen group was 3.4 cases for every 1,000 women, compared with 6.8 cases for every 1,000 women receiving placebo.³ Overall, the reduction in invasive breast cancer with tamoxifen was 49% (P<.00001). When broken down by age group, the reduction was:

• 44% in women 35 to 49 years old
• 51% in women 50 to 59 years old
• 55% in women 60 years and older.

Even noninvasive breast cancer was reduced with tamoxifen

Tamoxifen decreased the incidence of noninvasive breast cancer (ductal carcinoma in situ [DCIS]) by 50%. Expanded use of mammography has increased the detection of DCIS. Most DCIS lesions appear to be estrogen-receptor positive.⁸

In addition, tamoxifen reduced breast cancer risk in women who had a history of lobular carcinoma in situ (LCIS), a precancer, by 56%, and it reduced the risk of breast cancer in women who had a history of atypical hyperplasia by 86%. Overall, tamoxifen reduced the occurrence of estrogen-positive tumors by 69%, but had no impact on the incidence of estrogen-receptor–negative tumors.

The BCPT was stopped 14 months before planned because the Data and Safety Monitoring Board felt it was unethical to continue to allow one half of such high-risk participants to take placebo in light of the dramatic reduction in both invasive and noninvasive breast cancer among women who took tamoxifen.

In postmenopausal women, tamoxifen increases some risks

Two secondary endpoints of the BCPT are worthy of consideration:

• The overall relative risk (RR) of endometrial cancer associated with tamoxifen therapy in healthy women was 2.53 (95% confidence interval [CI], 1.35, 4.97). However, further analysis by age yielded a RR of 4.01 in women who were older than 50 years (95% CI, 1.70, 10.90), compared with a RR of 1.21 in women 49 years and younger (95% CI, 0.41, 3.60).
• The same age distinction held true for deep venous thrombosis (DVT) and pulmonary embolus, with no statistically significant increases in either in women 49 years and younger, but a RR of 1.71 and 3.19, respectively, in women 50 years and older. It is unclear whether the trial was sufficiently powered for this particular secondary endpoint.

These findings suggest that serious adverse events do not occur at the same magnitude in women younger than 50 years that they do in women 50 and older. The difference in the risk–benefit profile between younger and older women has significant clinical implications for the care of perimenopausal patients.

Risk of other malignancies was not affected by tamoxifen

Overall, invasive cancers other than those of the breast and uterus occurred at the same rate in the tamoxifen and placebo groups of the BCPT. The RR of death from any cause was 0.81 (95% CI, 0.56–1.16). There was a slight increase in the risk of myocardial infarction (RR, 1.11; 95% CI, 0.65–1.92) and a slight decrease in the risk of severe angina (RR, 0.93; 95% CI, 0.40–2.14) in tamoxifen users, although neither of these risks was statistically significant.

The overall RR of fracture of the hip, spine, or radius was 0.81 (95% CI, 0.63–1.05). There was a statistically significant increase in the number of women who had cataracts who then underwent cataract surgery in the tamoxifen group (RR, 1.57; 95% CI, 1.16–2.14).

Tamoxifen is approved as a preventive for high-risk women only

Based on the results of the BCPT, the US Food and Drug Administration (FDA) approved tamoxifen in October 1998 for the primary prevention of breast cancer in women who are at high risk of the disease. The FDA recommends that use of tamoxifen be limited to women at high risk because of the potentially serious side effects seen in clinical trials, including the BCPT.

The FDA did not define “high risk,” but it did recommend that the decision to use tamoxifen as chemopreventive therapy be based on thorough evaluation of the patient’s personal, family, and medical histories; her age; and her understanding of the risks and benefits of treatment.

The FDA also required the following language in the package insert:

• You should not take tamoxifen to reduce the risk of breast cancer unless you are at high risk of breast cancer. Certain conditions put women at high risk, and it is possible to calculate this risk for any woman. Breast cancer risk-assessment tools to help calculate your risk of breast cancer have been developed and are available to your health-care professional. You should discuss your risk with your healthcare professional.

CASE 1 RESOLVED

You determine that R. J. is an excellent candidate for tamoxifen by virtue of her significant risk of breast cancer. You are able to reassure her that, as the BCPT demonstrated, tamoxifen should not increase the risk of uterine cancer, DVT, or pulmonary embolism in a woman her age.

Raloxifene

CASE 2: Patient worries about breasts and bones

S. T. is a 58-year-old Caucasian mother of two whose own mother had breast cancer when she was 74 years old, and whose older sister was given a diagnosis of the malignancy 4 years ago.

S. T. had her first period when she was 11 years old, delivered her first child when she was 31, and entered menopause when she was 52. She is 5 ft 5 in tall and weighs 144 lb.

Her main reason for visiting you today is a breast Mammotome biopsy that showed ductal hyperplasia with atypia. She has been tested for a BRCA mutation, but the result was negative. Her Gail-model score is a 9.7% risk of developing breast cancer over the next 5 years, and a lifetime risk of 44.2%.

She also asks about osteoporosis prevention, given that a dual-energy x-ray absorptiometry (DXA) scan 1 year ago yielded a T-score of –1.3 for her hip and –1.1 for her spine. Her World Health Organization FRAX 10-year risk of hip fracture is 0.7%, and her risk of major osteoporotic fracture is 8.6%.

How do you respond to her concerns?

This patient has a high risk of invasive breast cancer but does not meet criteria for pharmacotherapy for osteoporosis prevention. A good option for her would be raloxifene, a selective estrogen-receptor modulator (SERM) that has been shown to reduce the risk of breast cancer as well as osteoporosis. S. T. would benefit from it on the basis of its breast benefit alone.

The genesis of a drug with multiple benefits

Raloxifene is a benzothiophene derivative, unlike the triphenylethylene family from which tamoxifen is derived. Like tamoxifen, raloxifene was originally investigated as a treatment for advanced breast cancer.

Preclinical studies indicated that raloxifene had an antiproliferative effect on both estrogen-receptor–positive mammary tumors and estrogen-receptor–positive human breast cancer cell lines.⁹ In the 1980s, however, a small, phase-II trial revealed that raloxifene had no further antitumor effects in postmenopausal women with advanced breast cancer in whom tamoxifen had failed.¹⁰ After information surfaced about the neoplastic effect of tamoxifen on the uteri of postmenopausal women, interest in raloxifene revived.¹¹

Raloxifene has estrogen-agonistic activity on bone remodeling and lipid metabolism and was approved by the FDA for prevention of osteoporosis in postmenopausal women in December 1997. Its indication was extended to treatment of osteoporosis 2 years later.

Raloxifene appears to have no effect on the endometrium of postmenopausal women, compared with placebo. In a 12-month comparative trial, there was no difference in endometrial thickness, endoluminal masses, proliferation, or hyperplasia between the raloxifene and placebo groups.¹² This finding corroborates earlier evidence that raloxifene does not cause endometrial hyperplasia or cancer and is not associated with vaginal bleeding or increased endometrial thickness, as measured by transvaginal ultrasonography.

A big difference between raloxifene and tamoxifen, therefore, is their varying effect on the uterus of postmenopausal women.

Additional clinical trials confirm anticancer action of raloxifene

Preclinical data in animal models suggested that, like tamoxifen, raloxifene has potent antiestrogenic effects on breast tissue.⁹ The MORE trial involved 7,705 postmenopausal women up to 80 years old who had established osteoporosis.¹³ In that trial, participants were randomized to raloxifene or placebo. Bone mineral density (BMD) and fracture incidence were the primary endpoints; breast cancer was a secondary endpoint.

Over the 4 years of the trial, raloxifene significantly reduced the incidence of all invasive breast cancers by 72%, compared with placebo (RR, 0.28; 95% CI, 0.17–0.46). Raloxifene also significantly reduced the incidence of invasive estrogen-receptor–positive tumors by 84%, compared with placebo (RR, 0.16; 95% CI, 0.09–0.30), but had no effect on estrogen-receptor–negative tumors. The incidence of vaginal bleeding, breast pain, and endometrial cancer in the raloxifene group did not differ significantly from that of the placebo group.

Like tamoxifen, raloxifene appeared to be associated with an increased risk of thromboembolic disease, including DVT and pulmonary embolism, which developed in 1.1% of women taking raloxifene, compared with 0.5% of women in the placebo group (P=.003).

In a 4-year continuation of the MORE trial, known as the Continuing Outcomes Relevant to Evista, or CORE, trial, 5,231 women were randomized to continue raloxifene or placebo.¹⁴ Over the 8 years of the combined trials, the incidence of invasive breast cancer was reduced by 66% in the raloxifene group (RR, 0.34; 95% CI, 0.22–0.50). The 8-year data are extremely clinically relevant, in that raloxifene has no time limit, whereas tamoxifen is usually prescribed for no longer than 5 years.

Raloxifene is not approved for use in premenopausal women. SERM compounds, which are structurally similar to clomiphene citrate, seem to have different effects in premenopausal and postmenopausal women, as evidenced by tamoxifen’s differing effects by age in the BCPT.

Other investigations of raloxifene confirm its value in high-risk women

To compare the clinical safety and efficacy of tamoxifen and raloxifene in reducing the risk of breast cancer among healthy women, the Study of Tamoxifen and Raloxifene (STAR) was initiated in 1999.¹⁵ In that trial, 19,747 postmenopausal women older than 35 years were blindly assigned to raloxifene 60 mg or tamoxifen 20 mg daily.

Baseline characteristics of subjects in STAR are summarized in TABLE 2 . Mean age was 58.5 years. All women had a 5-year risk of developing breast cancer that exceeded 1.66%, according to the Gail model. The average Gail score was 4.03% (standard deviation, ±2.17%). Because it would have been unethical to subject high-risk women to a placebo group in light of the findings of the BCPT, there was no placebo control.

TABLE 2

Baseline characteristics of women
in the Study of Tamoxifen and Raloxifene (STAR) trial

Here are noteworthy findings of the STAR trial:

• 163 cases of invasive breast cancer occurred in the tamoxifen group, compared with 168 among women taking raloxifene (RR, 1.02; 95% CI, 0.82–1.28).
• 36 cases of uterine cancer occurred in the tamoxifen group, compared with 23 among women taking raloxifene (RR, 0.62; 95% CI, 0.35–1.08). Earlier studies had shown a marked difference in the rate of uterine cancer between these agents. Although the difference here is not statistically significant, uterine cancer was not an endpoint of the study; nor was the study powered to explore this difference.
• The number of hysterectomies among women who were diagnosed with endometrial hyperplasia with or without atypia was, proportionally, significantly higher among women taking tamoxifen ( TABLE 3 ).
• No difference between groups was found for other invasive cancers, ischemic heart events, or stroke.
• Thromboembolic events occurred less frequently in the raloxifene group (RR, 0.70; 95% CI, 0.54–0.91). However, both raloxifene and tamoxifen have consistently been associated with a twofold to threefold increase in the risk of thromboembolic events, compared with placebo.
• Vasomotor symptoms and leg cramps increased in frequency and severity among women in both groups of the trial. These symptoms appear to be less common and less severe among women who are older and more remote from the onset of menopause.

TABLE 3

Relative risk of hysterectomy and uterine hyperplasia during STAR

What is raloxifene’s effect on the heart?

The Raloxifene Use for The Heart (RUTH) trial explored the primary endpoints of coronary artery disease (CAD) and breast cancer in more than 10,000 women who had CAD or multiple risk factors for it.¹⁶ This study began prior to the Women’s Health Initiative, at a time when hormone replacement therapy was widely believed to reduce CAD.

In the double-blinded, randomized, placebo-controlled RUTH trial, raloxifene had no significant effect on primary coronary events (533 vs 553; hazard ratio [HR], 0.95; 95% CI, 0.84–1.07). Even in this population, however, there was a 44% reduction in invasive breast cancer (40 vs 70 events; HR, 0.56; 95% CI, 0.38–0.83).

Based on these results, the FDA approved raloxifene for the “reduction in risk of invasive breast cancer in postmenopausal women at high risk for breast cancer,” as well as for the “reduction in risk of invasive breast cancer in postmenopausal women with osteoporosis” ( FIGURE ).

FIGURE How raloxifene reduced invasive breast cancer in three trials

Raloxifene significantly reduced the risk of cancer, compared with placebo, in the Raloxifene Use for The Heart (RUTH), Multiple Outcomes of Raloxifene Evaluation (MORE), and Continuing Outcomes Relevant to Evista (CORE) trials.

CASE 2 RESOLVED

S. T. begins taking raloxifene 60 mg daily to lower her risk of invasive breast cancer. Although she temporarily experienced hot flashes after initiating the drug, they are only mildly bothersome, and she continues raloxifene therapy. She says she is grateful that there is an agent that can help her reduce the likelihood that she will develop breast cancer, and protection of her BMD is an added benefit.

CASE 3: At risk for both breast cancer and bone fracture

A. N., 63, is a nulliparous Caucasian woman who weighs 134 lb and stands 5 ft 4 in tall. She reached menarche when she was 12 years old and entered menopause at 49.

Although A. N. has never had a breast abnormality, her 59-year-old sister was just given a diagnosis of breast cancer. Her Gail score reveals that she has a 3.1% risk of developing breast cancer over the next 5 years.

In addition to her concerns about breast cancer, A. N. is worried about hip fracture—because her mother suffered one after menopause and because her T-score is –1.9 at the hip and –2.1 at the spine. A. N. has used steroids off and on for much of her life for asthma. Her FRAX score indicates that she has a 2.8% risk of hip fracture and a 25% risk of major osteoporotic fracture over the next 10 years.

What do you offer her?

Because of new FRAX criteria, this osteopenic woman is now a candidate for medication to reduce her risk of major osteoporotic fracture, and raloxifene is a good option. Her Gail score of 3.1% also makes her a good candidate for breast cancer risk reduction with raloxifene.

CASE 3 RESOLVED

Because A. N. needs an agent that benefits both breast and bone, you prescribe raloxifene. The drug should significantly reduce her risk of both invasive breast cancer and bone fracture, without increasing her risk of endometrial hyperplasia and cancer, both of which are associated with tamoxifen in her age group.

Aromatase inhibitors

A fairly new class of drugs being explored for their ability to reduce the risk of breast cancer is aromatase inhibitors. Substantial evidence suggests that estrogens facilitate the development of breast cancer in animals and in women, although the precise mechanism remains unknown.¹⁷ The most commonly held theory is that estrogen stimulates proliferation of breast cells and thereby increases the risk of genetic mutation that could lead to cancer.

Aromatase inhibitors block peripheral conversion of androstenedione to estrogens. In premenopausal women, the primary site of this action is in the ovary. In postmenopausal women, this conversion occurs primarily in extraovarian sites, including the adrenal glands, adipose tissue, liver, muscle, and skin.

Aromatase inhibitors may be more effective than SERMs in preventing breast cancer because of their dual role: blocking both the initiation and promotion of breast cancer.¹⁸ These agents reduce levels of the genotoxic metabolites of estradiol by lowering estradiol concentration in tissue. At the same time, aromatase inhibitors also block tumor promotion by lowering tissue levels of estrogen and preventing cell proliferation.

The main drawback of these agents—besides the fact that they are not FDA-approved for reducing risk—is their antiestrogenic effect on bone and lipid metabolism. They also induce vasomotor symptoms.

Studies of third-generation aromatase inhibitors in the prevention of breast cancer are under way in high-risk women. These agents include anastrozole, exemestane, and letrozole.

The author reports that he is a consultant to Eli Lilly, Pfizer, and Wyeth, and a speaker for Eli Lilly and Wyeth.

CASE 1: Premenopausal woman
at high risk of breast cancer

R. J. is a 43-year-old, nulliparous woman who reached menarche at age 11. She has undergone two breast biopsies, the most recent of which revealed ductal hyperplasia with marked atypia.

R. J.’s sister had breast cancer at 49 years of age; her mother had breast cancer at 66 years. Because of R. J.’s family history, she underwent testing for a BRCA mutation. The result was negative.

R. J. has come to your office today to find out if she can do anything to reduce her risk of breast cancer. What options can you offer?

The most common method of “prevention” of breast cancer involves early detection and assessment of abnormalities through frequent surveillance with mammography. Some women who have dense breasts, a history of breast biopsy, or other risk factors for breast cancer may benefit from intensive surveillance with both mammography and ultrasonography—and, in some cases, magnetic resonance imaging.

More aggressive options include:

• the use of a chemopreventive agent such as tamoxifen or raloxifene
• in rare cases—usually when a BRCA mutation is present—prophylactic mastectomy.

Before it is possible to determine the optimal approach for a particular woman, it is necessary to conduct an individualized assessment of her risk—that is, to estimate the probability that she will develop breast cancer over a defined period of time. Such an estimate is also useful for designing prevention trials in high-risk subsets of the population. (Prevention trials differ from therapeutic clinical trials in that asymptomatic healthy women are exposed to potentially toxic interventions for prolonged periods to reduce their risk of breast cancer.)

This article describes chemopreventive options for women at high risk, based on individualized risk assessment using the Gail model.

(Editor’s note: For additional discussion of the important role ObGyns play in the fight against breast cancer, see Editor in Chief Dr. Robert L. Barbieri’s Editorial.)

What constitutes high risk?

You can estimate the likelihood that a woman like your patient may develop breast cancer using various individual risk factors ( TABLE 1 ), but estimates for combinations of risk factors are preferable. The Gail model takes into account some nongenetic factors, such as parity and age at menarche, but also genetic factors, such as family history. The model calculates a woman’s individualized breast cancer probability and yields a numerical risk (a percentage) that she will develop invasive breast cancer over the next 5 years; it also yields an estimate of her risk of developing the malignancy over the remainder of her life.^1,2

A Gail-model 5-year estimate of 1.66% or higher denotes a high risk of developing breast cancer. That benchmark was the one employed in the Breast Cancer Prevention Trial (BCPT), conducted as part of the National Surgical Adjuvant Breast and Bowel Project (NSABP).³

TABLE 1

What are the risk factors for breast cancer?
And what degree of relative risk do they confer?

Weaknesses of the Gail model

The Gail model’s approach to estimating risk has some limitations. The model uses the number of prior breast biopsies in its assessment—but the relative risk associated with prior biopsy is smaller for women older than 50 years than it is for younger women.

Furthermore, data on which Gail bases its estimates were collected in the late 1970s and early 1980s. Since then, the increasing ease of breast histopathologic assessment—through fine-needle aspiration and outpatient core-needle biopsy—has confused the issue of just what constitutes a breast “biopsy.” (Most patients surveyed consider it to be any histologic sampling of the breast.)

As a result, the 1.66% cutoff becomes somewhat difficult to interpret in light of current practice.

Consider the following example. A 50-year-old nulliparous Caucasian woman reached menarche when she was 11 years old, has never had a biopsy, and has no first-degree relatives with breast cancer. According to the Gail model, her risk of developing breast cancer is 1.2% over the next 5 years and 10.8% in her lifetime. Therefore, she is not considered at high risk. If she were to give a history of three previous breast biopsies, however, none of them showing hyperplasia, her 5-year risk would rise to 1.8% and push her over the line into the high-risk category.

Compare her situation to that of R. J., the nulliparous woman described in Case 1. R. J. also reached menarche at 11 years, but she has had two breast biopsies (one of which showed atypical hyperplasia) and has two first-degree relatives who have had breast cancer. Her Gail score shows a 5-year risk of breast cancer of 13.5% (the norm for a 43-year-old woman is 0.8%), and a lifetime risk of 69.2%. Clearly, she has a high risk of breast cancer.

How do we improve an imperfect science?

We need to identify objective findings that are patient-specific but highly correlative with the development of breast cancer. Patient-specific biomarkers have been proposed, such as ultrasensitive measurement of the serum estradiol level in postmenopausal women. In the Multiple Outcomes of Raloxifene Evaluation, also known as the MORE trial, women who experienced the greatest reduction in the rate of breast cancer during treatment with raloxifene were a subgroup who had the highest baseline level of serum estradiol—although, overall, all patients had an estradiol level well within the postmenopausal range (≤20 pmol/L).^4,5

How tamoxifen became a chemopreventive agent

Tamoxifen inhibits mammary tumors in mice and rats and suppresses hormone-dependent breast cancer cell lines in vitro.⁶ Clinical data from the Early Breast Cancer Trialists’ Collaborative Group yielded additional motivation for prevention trials with tamoxifen: Besides reducing the rate of recurrent breast cancer, tamoxifen reduced the risk of contralateral new-onset breast cancer by 47% after 5 years of adjuvant treatment.⁷ Preclinical findings in vitro and in animal models, coupled with clinical data and evidence of tamoxifen’s favorable effects on skeleton remodeling and lipid levels, led to a series of chemoprevention trials in the United States and Europe using tamoxifen.

In the aforementioned BCPT, launched in 1992, 13,388 women 35 years and older who were deemed to be at high risk of developing breast cancer were enrolled at numerous sites throughout the United States and Canada.³ The Gail model was used to select women for the trial—only those who had a 5-year risk of 1.66% or higher were included. Participants were randomly assigned to receive tamoxifen 20 mg or placebo daily for 5 years. The trial was terminated early because of the dramatic reduction in new-onset breast cancer with tamoxifen, compared with placebo.

The overall incidence of breast cancer in the tamoxifen group was 3.4 cases for every 1,000 women, compared with 6.8 cases for every 1,000 women receiving placebo.³ Overall, the reduction in invasive breast cancer with tamoxifen was 49% (P<.00001). When broken down by age group, the reduction was:

• 44% in women 35 to 49 years old
• 51% in women 50 to 59 years old
• 55% in women 60 years and older.

Even noninvasive breast cancer was reduced with tamoxifen

Tamoxifen decreased the incidence of noninvasive breast cancer (ductal carcinoma in situ [DCIS]) by 50%. Expanded use of mammography has increased the detection of DCIS. Most DCIS lesions appear to be estrogen-receptor positive.⁸

In addition, tamoxifen reduced breast cancer risk in women who had a history of lobular carcinoma in situ (LCIS), a precancer, by 56%, and it reduced the risk of breast cancer in women who had a history of atypical hyperplasia by 86%. Overall, tamoxifen reduced the occurrence of estrogen-positive tumors by 69%, but had no impact on the incidence of estrogen-receptor–negative tumors.

The BCPT was stopped 14 months before planned because the Data and Safety Monitoring Board felt it was unethical to continue to allow one half of such high-risk participants to take placebo in light of the dramatic reduction in both invasive and noninvasive breast cancer among women who took tamoxifen.

In postmenopausal women, tamoxifen increases some risks

Two secondary endpoints of the BCPT are worthy of consideration:

• The overall relative risk (RR) of endometrial cancer associated with tamoxifen therapy in healthy women was 2.53 (95% confidence interval [CI], 1.35, 4.97). However, further analysis by age yielded a RR of 4.01 in women who were older than 50 years (95% CI, 1.70, 10.90), compared with a RR of 1.21 in women 49 years and younger (95% CI, 0.41, 3.60).
• The same age distinction held true for deep venous thrombosis (DVT) and pulmonary embolus, with no statistically significant increases in either in women 49 years and younger, but a RR of 1.71 and 3.19, respectively, in women 50 years and older. It is unclear whether the trial was sufficiently powered for this particular secondary endpoint.

These findings suggest that serious adverse events do not occur at the same magnitude in women younger than 50 years that they do in women 50 and older. The difference in the risk–benefit profile between younger and older women has significant clinical implications for the care of perimenopausal patients.

Risk of other malignancies was not affected by tamoxifen

Overall, invasive cancers other than those of the breast and uterus occurred at the same rate in the tamoxifen and placebo groups of the BCPT. The RR of death from any cause was 0.81 (95% CI, 0.56–1.16). There was a slight increase in the risk of myocardial infarction (RR, 1.11; 95% CI, 0.65–1.92) and a slight decrease in the risk of severe angina (RR, 0.93; 95% CI, 0.40–2.14) in tamoxifen users, although neither of these risks was statistically significant.

The overall RR of fracture of the hip, spine, or radius was 0.81 (95% CI, 0.63–1.05). There was a statistically significant increase in the number of women who had cataracts who then underwent cataract surgery in the tamoxifen group (RR, 1.57; 95% CI, 1.16–2.14).

Tamoxifen is approved as a preventive for high-risk women only

Based on the results of the BCPT, the US Food and Drug Administration (FDA) approved tamoxifen in October 1998 for the primary prevention of breast cancer in women who are at high risk of the disease. The FDA recommends that use of tamoxifen be limited to women at high risk because of the potentially serious side effects seen in clinical trials, including the BCPT.

The FDA did not define “high risk,” but it did recommend that the decision to use tamoxifen as chemopreventive therapy be based on thorough evaluation of the patient’s personal, family, and medical histories; her age; and her understanding of the risks and benefits of treatment.

The FDA also required the following language in the package insert:

• You should not take tamoxifen to reduce the risk of breast cancer unless you are at high risk of breast cancer. Certain conditions put women at high risk, and it is possible to calculate this risk for any woman. Breast cancer risk-assessment tools to help calculate your risk of breast cancer have been developed and are available to your health-care professional. You should discuss your risk with your healthcare professional.

CASE 1 RESOLVED

You determine that R. J. is an excellent candidate for tamoxifen by virtue of her significant risk of breast cancer. You are able to reassure her that, as the BCPT demonstrated, tamoxifen should not increase the risk of uterine cancer, DVT, or pulmonary embolism in a woman her age.

Raloxifene

CASE 2: Patient worries about breasts and bones

S. T. is a 58-year-old Caucasian mother of two whose own mother had breast cancer when she was 74 years old, and whose older sister was given a diagnosis of the malignancy 4 years ago.

S. T. had her first period when she was 11 years old, delivered her first child when she was 31, and entered menopause when she was 52. She is 5 ft 5 in tall and weighs 144 lb.

Her main reason for visiting you today is a breast Mammotome biopsy that showed ductal hyperplasia with atypia. She has been tested for a BRCA mutation, but the result was negative. Her Gail-model score is a 9.7% risk of developing breast cancer over the next 5 years, and a lifetime risk of 44.2%.

She also asks about osteoporosis prevention, given that a dual-energy x-ray absorptiometry (DXA) scan 1 year ago yielded a T-score of –1.3 for her hip and –1.1 for her spine. Her World Health Organization FRAX 10-year risk of hip fracture is 0.7%, and her risk of major osteoporotic fracture is 8.6%.

How do you respond to her concerns?

This patient has a high risk of invasive breast cancer but does not meet criteria for pharmacotherapy for osteoporosis prevention. A good option for her would be raloxifene, a selective estrogen-receptor modulator (SERM) that has been shown to reduce the risk of breast cancer as well as osteoporosis. S. T. would benefit from it on the basis of its breast benefit alone.

The genesis of a drug with multiple benefits

Raloxifene is a benzothiophene derivative, unlike the triphenylethylene family from which tamoxifen is derived. Like tamoxifen, raloxifene was originally investigated as a treatment for advanced breast cancer.

Preclinical studies indicated that raloxifene had an antiproliferative effect on both estrogen-receptor–positive mammary tumors and estrogen-receptor–positive human breast cancer cell lines.⁹ In the 1980s, however, a small, phase-II trial revealed that raloxifene had no further antitumor effects in postmenopausal women with advanced breast cancer in whom tamoxifen had failed.¹⁰ After information surfaced about the neoplastic effect of tamoxifen on the uteri of postmenopausal women, interest in raloxifene revived.¹¹

Raloxifene has estrogen-agonistic activity on bone remodeling and lipid metabolism and was approved by the FDA for prevention of osteoporosis in postmenopausal women in December 1997. Its indication was extended to treatment of osteoporosis 2 years later.

Raloxifene appears to have no effect on the endometrium of postmenopausal women, compared with placebo. In a 12-month comparative trial, there was no difference in endometrial thickness, endoluminal masses, proliferation, or hyperplasia between the raloxifene and placebo groups.¹² This finding corroborates earlier evidence that raloxifene does not cause endometrial hyperplasia or cancer and is not associated with vaginal bleeding or increased endometrial thickness, as measured by transvaginal ultrasonography.

A big difference between raloxifene and tamoxifen, therefore, is their varying effect on the uterus of postmenopausal women.

Additional clinical trials confirm anticancer action of raloxifene

Preclinical data in animal models suggested that, like tamoxifen, raloxifene has potent antiestrogenic effects on breast tissue.⁹ The MORE trial involved 7,705 postmenopausal women up to 80 years old who had established osteoporosis.¹³ In that trial, participants were randomized to raloxifene or placebo. Bone mineral density (BMD) and fracture incidence were the primary endpoints; breast cancer was a secondary endpoint.

Over the 4 years of the trial, raloxifene significantly reduced the incidence of all invasive breast cancers by 72%, compared with placebo (RR, 0.28; 95% CI, 0.17–0.46). Raloxifene also significantly reduced the incidence of invasive estrogen-receptor–positive tumors by 84%, compared with placebo (RR, 0.16; 95% CI, 0.09–0.30), but had no effect on estrogen-receptor–negative tumors. The incidence of vaginal bleeding, breast pain, and endometrial cancer in the raloxifene group did not differ significantly from that of the placebo group.

Like tamoxifen, raloxifene appeared to be associated with an increased risk of thromboembolic disease, including DVT and pulmonary embolism, which developed in 1.1% of women taking raloxifene, compared with 0.5% of women in the placebo group (P=.003).

In a 4-year continuation of the MORE trial, known as the Continuing Outcomes Relevant to Evista, or CORE, trial, 5,231 women were randomized to continue raloxifene or placebo.¹⁴ Over the 8 years of the combined trials, the incidence of invasive breast cancer was reduced by 66% in the raloxifene group (RR, 0.34; 95% CI, 0.22–0.50). The 8-year data are extremely clinically relevant, in that raloxifene has no time limit, whereas tamoxifen is usually prescribed for no longer than 5 years.

Raloxifene is not approved for use in premenopausal women. SERM compounds, which are structurally similar to clomiphene citrate, seem to have different effects in premenopausal and postmenopausal women, as evidenced by tamoxifen’s differing effects by age in the BCPT.

Other investigations of raloxifene confirm its value in high-risk women

To compare the clinical safety and efficacy of tamoxifen and raloxifene in reducing the risk of breast cancer among healthy women, the Study of Tamoxifen and Raloxifene (STAR) was initiated in 1999.¹⁵ In that trial, 19,747 postmenopausal women older than 35 years were blindly assigned to raloxifene 60 mg or tamoxifen 20 mg daily.

Baseline characteristics of subjects in STAR are summarized in TABLE 2 . Mean age was 58.5 years. All women had a 5-year risk of developing breast cancer that exceeded 1.66%, according to the Gail model. The average Gail score was 4.03% (standard deviation, ±2.17%). Because it would have been unethical to subject high-risk women to a placebo group in light of the findings of the BCPT, there was no placebo control.

TABLE 2

Baseline characteristics of women
in the Study of Tamoxifen and Raloxifene (STAR) trial

Here are noteworthy findings of the STAR trial:

• 163 cases of invasive breast cancer occurred in the tamoxifen group, compared with 168 among women taking raloxifene (RR, 1.02; 95% CI, 0.82–1.28).
• 36 cases of uterine cancer occurred in the tamoxifen group, compared with 23 among women taking raloxifene (RR, 0.62; 95% CI, 0.35–1.08). Earlier studies had shown a marked difference in the rate of uterine cancer between these agents. Although the difference here is not statistically significant, uterine cancer was not an endpoint of the study; nor was the study powered to explore this difference.
• The number of hysterectomies among women who were diagnosed with endometrial hyperplasia with or without atypia was, proportionally, significantly higher among women taking tamoxifen ( TABLE 3 ).
• No difference between groups was found for other invasive cancers, ischemic heart events, or stroke.
• Thromboembolic events occurred less frequently in the raloxifene group (RR, 0.70; 95% CI, 0.54–0.91). However, both raloxifene and tamoxifen have consistently been associated with a twofold to threefold increase in the risk of thromboembolic events, compared with placebo.
• Vasomotor symptoms and leg cramps increased in frequency and severity among women in both groups of the trial. These symptoms appear to be less common and less severe among women who are older and more remote from the onset of menopause.

TABLE 3

Relative risk of hysterectomy and uterine hyperplasia during STAR

What is raloxifene’s effect on the heart?

The Raloxifene Use for The Heart (RUTH) trial explored the primary endpoints of coronary artery disease (CAD) and breast cancer in more than 10,000 women who had CAD or multiple risk factors for it.¹⁶ This study began prior to the Women’s Health Initiative, at a time when hormone replacement therapy was widely believed to reduce CAD.

In the double-blinded, randomized, placebo-controlled RUTH trial, raloxifene had no significant effect on primary coronary events (533 vs 553; hazard ratio [HR], 0.95; 95% CI, 0.84–1.07). Even in this population, however, there was a 44% reduction in invasive breast cancer (40 vs 70 events; HR, 0.56; 95% CI, 0.38–0.83).

Based on these results, the FDA approved raloxifene for the “reduction in risk of invasive breast cancer in postmenopausal women at high risk for breast cancer,” as well as for the “reduction in risk of invasive breast cancer in postmenopausal women with osteoporosis” ( FIGURE ).

FIGURE How raloxifene reduced invasive breast cancer in three trials

Raloxifene significantly reduced the risk of cancer, compared with placebo, in the Raloxifene Use for The Heart (RUTH), Multiple Outcomes of Raloxifene Evaluation (MORE), and Continuing Outcomes Relevant to Evista (CORE) trials.

CASE 2 RESOLVED

S. T. begins taking raloxifene 60 mg daily to lower her risk of invasive breast cancer. Although she temporarily experienced hot flashes after initiating the drug, they are only mildly bothersome, and she continues raloxifene therapy. She says she is grateful that there is an agent that can help her reduce the likelihood that she will develop breast cancer, and protection of her BMD is an added benefit.

CASE 3: At risk for both breast cancer and bone fracture

A. N., 63, is a nulliparous Caucasian woman who weighs 134 lb and stands 5 ft 4 in tall. She reached menarche when she was 12 years old and entered menopause at 49.

Although A. N. has never had a breast abnormality, her 59-year-old sister was just given a diagnosis of breast cancer. Her Gail score reveals that she has a 3.1% risk of developing breast cancer over the next 5 years.

In addition to her concerns about breast cancer, A. N. is worried about hip fracture—because her mother suffered one after menopause and because her T-score is –1.9 at the hip and –2.1 at the spine. A. N. has used steroids off and on for much of her life for asthma. Her FRAX score indicates that she has a 2.8% risk of hip fracture and a 25% risk of major osteoporotic fracture over the next 10 years.

What do you offer her?

Because of new FRAX criteria, this osteopenic woman is now a candidate for medication to reduce her risk of major osteoporotic fracture, and raloxifene is a good option. Her Gail score of 3.1% also makes her a good candidate for breast cancer risk reduction with raloxifene.

CASE 3 RESOLVED

Because A. N. needs an agent that benefits both breast and bone, you prescribe raloxifene. The drug should significantly reduce her risk of both invasive breast cancer and bone fracture, without increasing her risk of endometrial hyperplasia and cancer, both of which are associated with tamoxifen in her age group.

Aromatase inhibitors

A fairly new class of drugs being explored for their ability to reduce the risk of breast cancer is aromatase inhibitors. Substantial evidence suggests that estrogens facilitate the development of breast cancer in animals and in women, although the precise mechanism remains unknown.¹⁷ The most commonly held theory is that estrogen stimulates proliferation of breast cells and thereby increases the risk of genetic mutation that could lead to cancer.

Aromatase inhibitors block peripheral conversion of androstenedione to estrogens. In premenopausal women, the primary site of this action is in the ovary. In postmenopausal women, this conversion occurs primarily in extraovarian sites, including the adrenal glands, adipose tissue, liver, muscle, and skin.

Aromatase inhibitors may be more effective than SERMs in preventing breast cancer because of their dual role: blocking both the initiation and promotion of breast cancer.¹⁸ These agents reduce levels of the genotoxic metabolites of estradiol by lowering estradiol concentration in tissue. At the same time, aromatase inhibitors also block tumor promotion by lowering tissue levels of estrogen and preventing cell proliferation.

The main drawback of these agents—besides the fact that they are not FDA-approved for reducing risk—is their antiestrogenic effect on bone and lipid metabolism. They also induce vasomotor symptoms.

Studies of third-generation aromatase inhibitors in the prevention of breast cancer are under way in high-risk women. These agents include anastrozole, exemestane, and letrozole.

The author reports that he is a consultant to Eli Lilly, Pfizer, and Wyeth, and a speaker for Eli Lilly and Wyeth.

CASE 1: Premenopausal woman
at high risk of breast cancer

R. J. is a 43-year-old, nulliparous woman who reached menarche at age 11. She has undergone two breast biopsies, the most recent of which revealed ductal hyperplasia with marked atypia.

R. J.’s sister had breast cancer at 49 years of age; her mother had breast cancer at 66 years. Because of R. J.’s family history, she underwent testing for a BRCA mutation. The result was negative.

R. J. has come to your office today to find out if she can do anything to reduce her risk of breast cancer. What options can you offer?

The most common method of “prevention” of breast cancer involves early detection and assessment of abnormalities through frequent surveillance with mammography. Some women who have dense breasts, a history of breast biopsy, or other risk factors for breast cancer may benefit from intensive surveillance with both mammography and ultrasonography—and, in some cases, magnetic resonance imaging.

More aggressive options include:

• the use of a chemopreventive agent such as tamoxifen or raloxifene
• in rare cases—usually when a BRCA mutation is present—prophylactic mastectomy.

Before it is possible to determine the optimal approach for a particular woman, it is necessary to conduct an individualized assessment of her risk—that is, to estimate the probability that she will develop breast cancer over a defined period of time. Such an estimate is also useful for designing prevention trials in high-risk subsets of the population. (Prevention trials differ from therapeutic clinical trials in that asymptomatic healthy women are exposed to potentially toxic interventions for prolonged periods to reduce their risk of breast cancer.)

This article describes chemopreventive options for women at high risk, based on individualized risk assessment using the Gail model.

(Editor’s note: For additional discussion of the important role ObGyns play in the fight against breast cancer, see Editor in Chief Dr. Robert L. Barbieri’s Editorial.)

What constitutes high risk?

You can estimate the likelihood that a woman like your patient may develop breast cancer using various individual risk factors ( TABLE 1 ), but estimates for combinations of risk factors are preferable. The Gail model takes into account some nongenetic factors, such as parity and age at menarche, but also genetic factors, such as family history. The model calculates a woman’s individualized breast cancer probability and yields a numerical risk (a percentage) that she will develop invasive breast cancer over the next 5 years; it also yields an estimate of her risk of developing the malignancy over the remainder of her life.^1,2

A Gail-model 5-year estimate of 1.66% or higher denotes a high risk of developing breast cancer. That benchmark was the one employed in the Breast Cancer Prevention Trial (BCPT), conducted as part of the National Surgical Adjuvant Breast and Bowel Project (NSABP).³

TABLE 1

What are the risk factors for breast cancer?
And what degree of relative risk do they confer?

Weaknesses of the Gail model

The Gail model’s approach to estimating risk has some limitations. The model uses the number of prior breast biopsies in its assessment—but the relative risk associated with prior biopsy is smaller for women older than 50 years than it is for younger women.

Furthermore, data on which Gail bases its estimates were collected in the late 1970s and early 1980s. Since then, the increasing ease of breast histopathologic assessment—through fine-needle aspiration and outpatient core-needle biopsy—has confused the issue of just what constitutes a breast “biopsy.” (Most patients surveyed consider it to be any histologic sampling of the breast.)

As a result, the 1.66% cutoff becomes somewhat difficult to interpret in light of current practice.

Consider the following example. A 50-year-old nulliparous Caucasian woman reached menarche when she was 11 years old, has never had a biopsy, and has no first-degree relatives with breast cancer. According to the Gail model, her risk of developing breast cancer is 1.2% over the next 5 years and 10.8% in her lifetime. Therefore, she is not considered at high risk. If she were to give a history of three previous breast biopsies, however, none of them showing hyperplasia, her 5-year risk would rise to 1.8% and push her over the line into the high-risk category.

Compare her situation to that of R. J., the nulliparous woman described in Case 1. R. J. also reached menarche at 11 years, but she has had two breast biopsies (one of which showed atypical hyperplasia) and has two first-degree relatives who have had breast cancer. Her Gail score shows a 5-year risk of breast cancer of 13.5% (the norm for a 43-year-old woman is 0.8%), and a lifetime risk of 69.2%. Clearly, she has a high risk of breast cancer.

How do we improve an imperfect science?

We need to identify objective findings that are patient-specific but highly correlative with the development of breast cancer. Patient-specific biomarkers have been proposed, such as ultrasensitive measurement of the serum estradiol level in postmenopausal women. In the Multiple Outcomes of Raloxifene Evaluation, also known as the MORE trial, women who experienced the greatest reduction in the rate of breast cancer during treatment with raloxifene were a subgroup who had the highest baseline level of serum estradiol—although, overall, all patients had an estradiol level well within the postmenopausal range (≤20 pmol/L).^4,5

How tamoxifen became a chemopreventive agent

Tamoxifen inhibits mammary tumors in mice and rats and suppresses hormone-dependent breast cancer cell lines in vitro.⁶ Clinical data from the Early Breast Cancer Trialists’ Collaborative Group yielded additional motivation for prevention trials with tamoxifen: Besides reducing the rate of recurrent breast cancer, tamoxifen reduced the risk of contralateral new-onset breast cancer by 47% after 5 years of adjuvant treatment.⁷ Preclinical findings in vitro and in animal models, coupled with clinical data and evidence of tamoxifen’s favorable effects on skeleton remodeling and lipid levels, led to a series of chemoprevention trials in the United States and Europe using tamoxifen.

In the aforementioned BCPT, launched in 1992, 13,388 women 35 years and older who were deemed to be at high risk of developing breast cancer were enrolled at numerous sites throughout the United States and Canada.³ The Gail model was used to select women for the trial—only those who had a 5-year risk of 1.66% or higher were included. Participants were randomly assigned to receive tamoxifen 20 mg or placebo daily for 5 years. The trial was terminated early because of the dramatic reduction in new-onset breast cancer with tamoxifen, compared with placebo.

The overall incidence of breast cancer in the tamoxifen group was 3.4 cases for every 1,000 women, compared with 6.8 cases for every 1,000 women receiving placebo.³ Overall, the reduction in invasive breast cancer with tamoxifen was 49% (P<.00001). When broken down by age group, the reduction was:

• 44% in women 35 to 49 years old
• 51% in women 50 to 59 years old
• 55% in women 60 years and older.

Even noninvasive breast cancer was reduced with tamoxifen

Tamoxifen decreased the incidence of noninvasive breast cancer (ductal carcinoma in situ [DCIS]) by 50%. Expanded use of mammography has increased the detection of DCIS. Most DCIS lesions appear to be estrogen-receptor positive.⁸

In addition, tamoxifen reduced breast cancer risk in women who had a history of lobular carcinoma in situ (LCIS), a precancer, by 56%, and it reduced the risk of breast cancer in women who had a history of atypical hyperplasia by 86%. Overall, tamoxifen reduced the occurrence of estrogen-positive tumors by 69%, but had no impact on the incidence of estrogen-receptor–negative tumors.

The BCPT was stopped 14 months before planned because the Data and Safety Monitoring Board felt it was unethical to continue to allow one half of such high-risk participants to take placebo in light of the dramatic reduction in both invasive and noninvasive breast cancer among women who took tamoxifen.

In postmenopausal women, tamoxifen increases some risks

Two secondary endpoints of the BCPT are worthy of consideration:

• The overall relative risk (RR) of endometrial cancer associated with tamoxifen therapy in healthy women was 2.53 (95% confidence interval [CI], 1.35, 4.97). However, further analysis by age yielded a RR of 4.01 in women who were older than 50 years (95% CI, 1.70, 10.90), compared with a RR of 1.21 in women 49 years and younger (95% CI, 0.41, 3.60).
• The same age distinction held true for deep venous thrombosis (DVT) and pulmonary embolus, with no statistically significant increases in either in women 49 years and younger, but a RR of 1.71 and 3.19, respectively, in women 50 years and older. It is unclear whether the trial was sufficiently powered for this particular secondary endpoint.

These findings suggest that serious adverse events do not occur at the same magnitude in women younger than 50 years that they do in women 50 and older. The difference in the risk–benefit profile between younger and older women has significant clinical implications for the care of perimenopausal patients.

Risk of other malignancies was not affected by tamoxifen

Overall, invasive cancers other than those of the breast and uterus occurred at the same rate in the tamoxifen and placebo groups of the BCPT. The RR of death from any cause was 0.81 (95% CI, 0.56–1.16). There was a slight increase in the risk of myocardial infarction (RR, 1.11; 95% CI, 0.65–1.92) and a slight decrease in the risk of severe angina (RR, 0.93; 95% CI, 0.40–2.14) in tamoxifen users, although neither of these risks was statistically significant.

The overall RR of fracture of the hip, spine, or radius was 0.81 (95% CI, 0.63–1.05). There was a statistically significant increase in the number of women who had cataracts who then underwent cataract surgery in the tamoxifen group (RR, 1.57; 95% CI, 1.16–2.14).

Tamoxifen is approved as a preventive for high-risk women only

Based on the results of the BCPT, the US Food and Drug Administration (FDA) approved tamoxifen in October 1998 for the primary prevention of breast cancer in women who are at high risk of the disease. The FDA recommends that use of tamoxifen be limited to women at high risk because of the potentially serious side effects seen in clinical trials, including the BCPT.

The FDA did not define “high risk,” but it did recommend that the decision to use tamoxifen as chemopreventive therapy be based on thorough evaluation of the patient’s personal, family, and medical histories; her age; and her understanding of the risks and benefits of treatment.

The FDA also required the following language in the package insert:

• You should not take tamoxifen to reduce the risk of breast cancer unless you are at high risk of breast cancer. Certain conditions put women at high risk, and it is possible to calculate this risk for any woman. Breast cancer risk-assessment tools to help calculate your risk of breast cancer have been developed and are available to your health-care professional. You should discuss your risk with your healthcare professional.

CASE 1 RESOLVED

You determine that R. J. is an excellent candidate for tamoxifen by virtue of her significant risk of breast cancer. You are able to reassure her that, as the BCPT demonstrated, tamoxifen should not increase the risk of uterine cancer, DVT, or pulmonary embolism in a woman her age.

Raloxifene

CASE 2: Patient worries about breasts and bones

S. T. is a 58-year-old Caucasian mother of two whose own mother had breast cancer when she was 74 years old, and whose older sister was given a diagnosis of the malignancy 4 years ago.

S. T. had her first period when she was 11 years old, delivered her first child when she was 31, and entered menopause when she was 52. She is 5 ft 5 in tall and weighs 144 lb.

Her main reason for visiting you today is a breast Mammotome biopsy that showed ductal hyperplasia with atypia. She has been tested for a BRCA mutation, but the result was negative. Her Gail-model score is a 9.7% risk of developing breast cancer over the next 5 years, and a lifetime risk of 44.2%.

She also asks about osteoporosis prevention, given that a dual-energy x-ray absorptiometry (DXA) scan 1 year ago yielded a T-score of –1.3 for her hip and –1.1 for her spine. Her World Health Organization FRAX 10-year risk of hip fracture is 0.7%, and her risk of major osteoporotic fracture is 8.6%.

How do you respond to her concerns?

This patient has a high risk of invasive breast cancer but does not meet criteria for pharmacotherapy for osteoporosis prevention. A good option for her would be raloxifene, a selective estrogen-receptor modulator (SERM) that has been shown to reduce the risk of breast cancer as well as osteoporosis. S. T. would benefit from it on the basis of its breast benefit alone.

The genesis of a drug with multiple benefits

Raloxifene is a benzothiophene derivative, unlike the triphenylethylene family from which tamoxifen is derived. Like tamoxifen, raloxifene was originally investigated as a treatment for advanced breast cancer.

Preclinical studies indicated that raloxifene had an antiproliferative effect on both estrogen-receptor–positive mammary tumors and estrogen-receptor–positive human breast cancer cell lines.⁹ In the 1980s, however, a small, phase-II trial revealed that raloxifene had no further antitumor effects in postmenopausal women with advanced breast cancer in whom tamoxifen had failed.¹⁰ After information surfaced about the neoplastic effect of tamoxifen on the uteri of postmenopausal women, interest in raloxifene revived.¹¹

Raloxifene has estrogen-agonistic activity on bone remodeling and lipid metabolism and was approved by the FDA for prevention of osteoporosis in postmenopausal women in December 1997. Its indication was extended to treatment of osteoporosis 2 years later.

Raloxifene appears to have no effect on the endometrium of postmenopausal women, compared with placebo. In a 12-month comparative trial, there was no difference in endometrial thickness, endoluminal masses, proliferation, or hyperplasia between the raloxifene and placebo groups.¹² This finding corroborates earlier evidence that raloxifene does not cause endometrial hyperplasia or cancer and is not associated with vaginal bleeding or increased endometrial thickness, as measured by transvaginal ultrasonography.

A big difference between raloxifene and tamoxifen, therefore, is their varying effect on the uterus of postmenopausal women.

Additional clinical trials confirm anticancer action of raloxifene

Preclinical data in animal models suggested that, like tamoxifen, raloxifene has potent antiestrogenic effects on breast tissue.⁹ The MORE trial involved 7,705 postmenopausal women up to 80 years old who had established osteoporosis.¹³ In that trial, participants were randomized to raloxifene or placebo. Bone mineral density (BMD) and fracture incidence were the primary endpoints; breast cancer was a secondary endpoint.

Over the 4 years of the trial, raloxifene significantly reduced the incidence of all invasive breast cancers by 72%, compared with placebo (RR, 0.28; 95% CI, 0.17–0.46). Raloxifene also significantly reduced the incidence of invasive estrogen-receptor–positive tumors by 84%, compared with placebo (RR, 0.16; 95% CI, 0.09–0.30), but had no effect on estrogen-receptor–negative tumors. The incidence of vaginal bleeding, breast pain, and endometrial cancer in the raloxifene group did not differ significantly from that of the placebo group.

Like tamoxifen, raloxifene appeared to be associated with an increased risk of thromboembolic disease, including DVT and pulmonary embolism, which developed in 1.1% of women taking raloxifene, compared with 0.5% of women in the placebo group (P=.003).

In a 4-year continuation of the MORE trial, known as the Continuing Outcomes Relevant to Evista, or CORE, trial, 5,231 women were randomized to continue raloxifene or placebo.¹⁴ Over the 8 years of the combined trials, the incidence of invasive breast cancer was reduced by 66% in the raloxifene group (RR, 0.34; 95% CI, 0.22–0.50). The 8-year data are extremely clinically relevant, in that raloxifene has no time limit, whereas tamoxifen is usually prescribed for no longer than 5 years.

Raloxifene is not approved for use in premenopausal women. SERM compounds, which are structurally similar to clomiphene citrate, seem to have different effects in premenopausal and postmenopausal women, as evidenced by tamoxifen’s differing effects by age in the BCPT.

Other investigations of raloxifene confirm its value in high-risk women

To compare the clinical safety and efficacy of tamoxifen and raloxifene in reducing the risk of breast cancer among healthy women, the Study of Tamoxifen and Raloxifene (STAR) was initiated in 1999.¹⁵ In that trial, 19,747 postmenopausal women older than 35 years were blindly assigned to raloxifene 60 mg or tamoxifen 20 mg daily.

Baseline characteristics of subjects in STAR are summarized in TABLE 2 . Mean age was 58.5 years. All women had a 5-year risk of developing breast cancer that exceeded 1.66%, according to the Gail model. The average Gail score was 4.03% (standard deviation, ±2.17%). Because it would have been unethical to subject high-risk women to a placebo group in light of the findings of the BCPT, there was no placebo control.

TABLE 2

Baseline characteristics of women
in the Study of Tamoxifen and Raloxifene (STAR) trial

Here are noteworthy findings of the STAR trial:

• 163 cases of invasive breast cancer occurred in the tamoxifen group, compared with 168 among women taking raloxifene (RR, 1.02; 95% CI, 0.82–1.28).
• 36 cases of uterine cancer occurred in the tamoxifen group, compared with 23 among women taking raloxifene (RR, 0.62; 95% CI, 0.35–1.08). Earlier studies had shown a marked difference in the rate of uterine cancer between these agents. Although the difference here is not statistically significant, uterine cancer was not an endpoint of the study; nor was the study powered to explore this difference.
• The number of hysterectomies among women who were diagnosed with endometrial hyperplasia with or without atypia was, proportionally, significantly higher among women taking tamoxifen ( TABLE 3 ).
• No difference between groups was found for other invasive cancers, ischemic heart events, or stroke.
• Thromboembolic events occurred less frequently in the raloxifene group (RR, 0.70; 95% CI, 0.54–0.91). However, both raloxifene and tamoxifen have consistently been associated with a twofold to threefold increase in the risk of thromboembolic events, compared with placebo.
• Vasomotor symptoms and leg cramps increased in frequency and severity among women in both groups of the trial. These symptoms appear to be less common and less severe among women who are older and more remote from the onset of menopause.

TABLE 3

Relative risk of hysterectomy and uterine hyperplasia during STAR

What is raloxifene’s effect on the heart?

The Raloxifene Use for The Heart (RUTH) trial explored the primary endpoints of coronary artery disease (CAD) and breast cancer in more than 10,000 women who had CAD or multiple risk factors for it.¹⁶ This study began prior to the Women’s Health Initiative, at a time when hormone replacement therapy was widely believed to reduce CAD.

In the double-blinded, randomized, placebo-controlled RUTH trial, raloxifene had no significant effect on primary coronary events (533 vs 553; hazard ratio [HR], 0.95; 95% CI, 0.84–1.07). Even in this population, however, there was a 44% reduction in invasive breast cancer (40 vs 70 events; HR, 0.56; 95% CI, 0.38–0.83).

Based on these results, the FDA approved raloxifene for the “reduction in risk of invasive breast cancer in postmenopausal women at high risk for breast cancer,” as well as for the “reduction in risk of invasive breast cancer in postmenopausal women with osteoporosis” ( FIGURE ).

FIGURE How raloxifene reduced invasive breast cancer in three trials

Raloxifene significantly reduced the risk of cancer, compared with placebo, in the Raloxifene Use for The Heart (RUTH), Multiple Outcomes of Raloxifene Evaluation (MORE), and Continuing Outcomes Relevant to Evista (CORE) trials.

CASE 2 RESOLVED

S. T. begins taking raloxifene 60 mg daily to lower her risk of invasive breast cancer. Although she temporarily experienced hot flashes after initiating the drug, they are only mildly bothersome, and she continues raloxifene therapy. She says she is grateful that there is an agent that can help her reduce the likelihood that she will develop breast cancer, and protection of her BMD is an added benefit.

CASE 3: At risk for both breast cancer and bone fracture

A. N., 63, is a nulliparous Caucasian woman who weighs 134 lb and stands 5 ft 4 in tall. She reached menarche when she was 12 years old and entered menopause at 49.

Although A. N. has never had a breast abnormality, her 59-year-old sister was just given a diagnosis of breast cancer. Her Gail score reveals that she has a 3.1% risk of developing breast cancer over the next 5 years.

In addition to her concerns about breast cancer, A. N. is worried about hip fracture—because her mother suffered one after menopause and because her T-score is –1.9 at the hip and –2.1 at the spine. A. N. has used steroids off and on for much of her life for asthma. Her FRAX score indicates that she has a 2.8% risk of hip fracture and a 25% risk of major osteoporotic fracture over the next 10 years.

What do you offer her?

Because of new FRAX criteria, this osteopenic woman is now a candidate for medication to reduce her risk of major osteoporotic fracture, and raloxifene is a good option. Her Gail score of 3.1% also makes her a good candidate for breast cancer risk reduction with raloxifene.

CASE 3 RESOLVED

Because A. N. needs an agent that benefits both breast and bone, you prescribe raloxifene. The drug should significantly reduce her risk of both invasive breast cancer and bone fracture, without increasing her risk of endometrial hyperplasia and cancer, both of which are associated with tamoxifen in her age group.

Aromatase inhibitors

A fairly new class of drugs being explored for their ability to reduce the risk of breast cancer is aromatase inhibitors. Substantial evidence suggests that estrogens facilitate the development of breast cancer in animals and in women, although the precise mechanism remains unknown.¹⁷ The most commonly held theory is that estrogen stimulates proliferation of breast cells and thereby increases the risk of genetic mutation that could lead to cancer.

Aromatase inhibitors block peripheral conversion of androstenedione to estrogens. In premenopausal women, the primary site of this action is in the ovary. In postmenopausal women, this conversion occurs primarily in extraovarian sites, including the adrenal glands, adipose tissue, liver, muscle, and skin.

Aromatase inhibitors may be more effective than SERMs in preventing breast cancer because of their dual role: blocking both the initiation and promotion of breast cancer.¹⁸ These agents reduce levels of the genotoxic metabolites of estradiol by lowering estradiol concentration in tissue. At the same time, aromatase inhibitors also block tumor promotion by lowering tissue levels of estrogen and preventing cell proliferation.

The main drawback of these agents—besides the fact that they are not FDA-approved for reducing risk—is their antiestrogenic effect on bone and lipid metabolism. They also induce vasomotor symptoms.

Studies of third-generation aromatase inhibitors in the prevention of breast cancer are under way in high-risk women. These agents include anastrozole, exemestane, and letrozole.

Dr. Kelly K. Hunt discusses findings that sentinel lymph node (SLN) biopsy when done after --rather than before--neoadjuvant chemotherapy cuts the need for axillary dissections in patients with stage T2-T3 breast tumors . Sherry Boschert of the Global Medical News Network (GMNN) reports from the annual meeting of the American Surgical Association in Indian Wells, Calif.

Dr. Kelly K. Hunt discusses findings that sentinel lymph node (SLN) biopsy when done after --rather than before--neoadjuvant chemotherapy cuts the need for axillary dissections in patients with stage T2-T3 breast tumors . Sherry Boschert of the Global Medical News Network (GMNN) reports from the annual meeting of the American Surgical Association in Indian Wells, Calif.

Dr. Kelly K. Hunt discusses findings that sentinel lymph node (SLN) biopsy when done after --rather than before--neoadjuvant chemotherapy cuts the need for axillary dissections in patients with stage T2-T3 breast tumors . Sherry Boschert of the Global Medical News Network (GMNN) reports from the annual meeting of the American Surgical Association in Indian Wells, Calif.