Breast Cancer

Adjuvant radiotherapy reduces the risk for short-term recurrence in patients with early breast cancer, but it may have no impact on long-term recurrence or overall survival, based on a 30-year follow-up of the Scottish Breast Conservation Trial.

These findings suggest that patients with biology predicting late relapse may receive little benefit from adjuvant radiotherapy, lead author Linda J. Williams, PhD, of the University of Edinburgh in Scotland, and colleagues, reported.

“During the past 30 years, several randomized controlled trials have investigated the role of postoperative radiotherapy after breast-conserving surgery for early breast cancer,” the investigators wrote in The Lancet Oncology. “These trials showed that radiotherapy reduces the risk of local recurrence but were underpowered individually to detect a difference in overall survival.”
 

How Did the Present Study Increase Our Understanding of the Benefits of Adjuvant Radiotherapy in Early Breast Cancer?

The present analysis included data from a trial that began in 1985, when 589 patients with early breast cancer (tumors ≤ 4 cm [T1 or T2 and N0 or N1]) were randomized to receive either high-dose or no radiotherapy, with final cohorts including 291 patients and 294 patients, respectively. The radiotherapy was given 50 Gy in 20-25 fractions, either locally or locoregionally.

Estrogen receptor (ER)–positive patients (≥ 20 fmol/mg protein) received 5 years of daily oral tamoxifen. ER-poor patients (< 20 fmol/mg protein) received a chemotherapy combination of cyclophosphamide, methotrexate, and fluorouracil on a 21-day cycle for eight cycles.

Considering all data across a median follow-up of 17.5 years, adjuvant radiotherapy appeared to offer benefit, as it was associated with significantly lower ipsilateral breast tumor recurrence (16% vs 36%; hazard ratio [HR], 0.39; P < .0001).

But that tells only part of the story.

The positive impact of radiotherapy persisted for 1 decade (HR, 0.24; P < .0001), but risk beyond this point was no different between groups (HR, 0.98; P = .95).

“[The] benefit of radiotherapy was time dependent,” the investigators noted.

What’s more, median overall survival was no different between those who received radiotherapy and those who did not (18.7 vs 19.2 years; HR, 1.08; log-rank P = .43), and “reassuringly,” omitting radiotherapy did not increase the rate of distant metastasis.
 

How Might These Findings Influence Treatment Planning for Patients With Early Breast Cancer?

“The results can help clinicians to advise patients better about their choice to have radiotherapy or not if they better understand what benefits it does and does not bring,” the investigators wrote. “These results might provide clues perhaps to the biology of radiotherapy benefit, given that it does not prevent late recurrences, suggesting that patients whose biology predicts a late relapse only might not gain a benefit from radiotherapy.”

Gary M. Freedman, MD, chief of Women’s Health Service, Radiation Oncology, at Penn Medicine, Philadelphia, offered a different perspective.

“The study lumps together a local recurrence of breast cancer — that is relapse of the cancer years after treatment with lumpectomy and radiation — with the development of an entirely new breast cancer in the same breast,” Dr. Freedman said in a written comment. “When something comes back between years 0-5 and 0-8, we usually think of it as a true local recurrence arbitrarily, but beyond that they are new cancers.”

He went on to emphasize the clinical importance of reducing local recurrence within the first decade, noting that “this leads to much less morbidity and better quality of life for the patients.”

Dr. Freedman also shared his perspective on the survival data.

“Radiation did reduce breast cancer mortality very significantly — death from breast cancers went down from 46% to 37%,” he wrote (P = .054). “This is on the same level as chemo or hormone therapy. The study was not powered to detect significant differences in survival by radiation, but that has been shown with other meta-analyses.”
 

Are Findings From a Trial Started 30 Years Ago Still Relevant Today?

“Clearly the treatment of early breast cancer has advanced since the 1980s when the Scottish Conservation trial was launched,” study coauthor Ian Kunkler, MB, FRCR, of the University of Edinburgh, said in a written comment. “There is more breast screening, attention to clearing surgical margins of residual disease, more effective and longer periods of adjuvant hormonal therapy, reduced radiotherapy toxicity from more precise delivery. However, most anticancer treatments lose their effectiveness over time.”

He suggested that more trials are needed to confirm the present findings and reiterated that the lack of long-term recurrence benefit is most relevant for patients with disease features that predict late relapse, who “seem to gain little from adjuvant radiotherapy given as part of primary treatment.”

Dr. Kunkler noted that the observed benefit in the first decade supports the continued use of radiotherapy alongside anticancer drug treatment.

When asked the same question, Freedman emphasized the differences in treatment today vs the 1980s.

“The results of modern multidisciplinary cancer care are much, much better than these 30-year results,” Dr. Freedman said. “The risk for local recurrence in the breast after radiation is now about 2%-3% at 10 years in most studies.”

He also noted that modern radiotherapy techniques have “significantly lowered dose and risks to heart and lung,” compared with techniques used 30 years ago.

“A take-home point for the study is after breast conservation, whether or not you have radiation, you have to continue long-term screening mammograms for new breast cancers that may occur even decades later,” Dr. Freedman concluded.
 

How Might These Findings Impact Future Research Design and Funding?

“The findings should encourage trial funders to consider funding long-term follow-up beyond 10 years to assess benefits and risks of anticancer therapies,” Dr. Kunkler said. “The importance of long-term follow-up cannot be understated.”

This study was funded by Breast Cancer Institute (part of Edinburgh and Lothians Health Foundation), PFS Genomics (now part of Exact Sciences), the University of Edinburgh, and NHS Lothian. The investigators reported no conflicts of interest.

A version of this article first appeared on Medscape.com.

Adjuvant radiotherapy reduces the risk for short-term recurrence in patients with early breast cancer, but it may have no impact on long-term recurrence or overall survival, based on a 30-year follow-up of the Scottish Breast Conservation Trial.

These findings suggest that patients with biology predicting late relapse may receive little benefit from adjuvant radiotherapy, lead author Linda J. Williams, PhD, of the University of Edinburgh in Scotland, and colleagues, reported.

“During the past 30 years, several randomized controlled trials have investigated the role of postoperative radiotherapy after breast-conserving surgery for early breast cancer,” the investigators wrote in The Lancet Oncology. “These trials showed that radiotherapy reduces the risk of local recurrence but were underpowered individually to detect a difference in overall survival.”
 

How Did the Present Study Increase Our Understanding of the Benefits of Adjuvant Radiotherapy in Early Breast Cancer?

The present analysis included data from a trial that began in 1985, when 589 patients with early breast cancer (tumors ≤ 4 cm [T1 or T2 and N0 or N1]) were randomized to receive either high-dose or no radiotherapy, with final cohorts including 291 patients and 294 patients, respectively. The radiotherapy was given 50 Gy in 20-25 fractions, either locally or locoregionally.

Estrogen receptor (ER)–positive patients (≥ 20 fmol/mg protein) received 5 years of daily oral tamoxifen. ER-poor patients (< 20 fmol/mg protein) received a chemotherapy combination of cyclophosphamide, methotrexate, and fluorouracil on a 21-day cycle for eight cycles.

Considering all data across a median follow-up of 17.5 years, adjuvant radiotherapy appeared to offer benefit, as it was associated with significantly lower ipsilateral breast tumor recurrence (16% vs 36%; hazard ratio [HR], 0.39; P < .0001).

But that tells only part of the story.

The positive impact of radiotherapy persisted for 1 decade (HR, 0.24; P < .0001), but risk beyond this point was no different between groups (HR, 0.98; P = .95).

“[The] benefit of radiotherapy was time dependent,” the investigators noted.

What’s more, median overall survival was no different between those who received radiotherapy and those who did not (18.7 vs 19.2 years; HR, 1.08; log-rank P = .43), and “reassuringly,” omitting radiotherapy did not increase the rate of distant metastasis.
 

How Might These Findings Influence Treatment Planning for Patients With Early Breast Cancer?

“The results can help clinicians to advise patients better about their choice to have radiotherapy or not if they better understand what benefits it does and does not bring,” the investigators wrote. “These results might provide clues perhaps to the biology of radiotherapy benefit, given that it does not prevent late recurrences, suggesting that patients whose biology predicts a late relapse only might not gain a benefit from radiotherapy.”

Gary M. Freedman, MD, chief of Women’s Health Service, Radiation Oncology, at Penn Medicine, Philadelphia, offered a different perspective.

“The study lumps together a local recurrence of breast cancer — that is relapse of the cancer years after treatment with lumpectomy and radiation — with the development of an entirely new breast cancer in the same breast,” Dr. Freedman said in a written comment. “When something comes back between years 0-5 and 0-8, we usually think of it as a true local recurrence arbitrarily, but beyond that they are new cancers.”

He went on to emphasize the clinical importance of reducing local recurrence within the first decade, noting that “this leads to much less morbidity and better quality of life for the patients.”

Dr. Freedman also shared his perspective on the survival data.

“Radiation did reduce breast cancer mortality very significantly — death from breast cancers went down from 46% to 37%,” he wrote (P = .054). “This is on the same level as chemo or hormone therapy. The study was not powered to detect significant differences in survival by radiation, but that has been shown with other meta-analyses.”
 

Are Findings From a Trial Started 30 Years Ago Still Relevant Today?

“Clearly the treatment of early breast cancer has advanced since the 1980s when the Scottish Conservation trial was launched,” study coauthor Ian Kunkler, MB, FRCR, of the University of Edinburgh, said in a written comment. “There is more breast screening, attention to clearing surgical margins of residual disease, more effective and longer periods of adjuvant hormonal therapy, reduced radiotherapy toxicity from more precise delivery. However, most anticancer treatments lose their effectiveness over time.”

He suggested that more trials are needed to confirm the present findings and reiterated that the lack of long-term recurrence benefit is most relevant for patients with disease features that predict late relapse, who “seem to gain little from adjuvant radiotherapy given as part of primary treatment.”

Dr. Kunkler noted that the observed benefit in the first decade supports the continued use of radiotherapy alongside anticancer drug treatment.

When asked the same question, Freedman emphasized the differences in treatment today vs the 1980s.

“The results of modern multidisciplinary cancer care are much, much better than these 30-year results,” Dr. Freedman said. “The risk for local recurrence in the breast after radiation is now about 2%-3% at 10 years in most studies.”

He also noted that modern radiotherapy techniques have “significantly lowered dose and risks to heart and lung,” compared with techniques used 30 years ago.

“A take-home point for the study is after breast conservation, whether or not you have radiation, you have to continue long-term screening mammograms for new breast cancers that may occur even decades later,” Dr. Freedman concluded.
 

How Might These Findings Impact Future Research Design and Funding?

“The findings should encourage trial funders to consider funding long-term follow-up beyond 10 years to assess benefits and risks of anticancer therapies,” Dr. Kunkler said. “The importance of long-term follow-up cannot be understated.”

This study was funded by Breast Cancer Institute (part of Edinburgh and Lothians Health Foundation), PFS Genomics (now part of Exact Sciences), the University of Edinburgh, and NHS Lothian. The investigators reported no conflicts of interest.

A version of this article first appeared on Medscape.com.

Adjuvant radiotherapy reduces the risk for short-term recurrence in patients with early breast cancer, but it may have no impact on long-term recurrence or overall survival, based on a 30-year follow-up of the Scottish Breast Conservation Trial.

These findings suggest that patients with biology predicting late relapse may receive little benefit from adjuvant radiotherapy, lead author Linda J. Williams, PhD, of the University of Edinburgh in Scotland, and colleagues, reported.

“During the past 30 years, several randomized controlled trials have investigated the role of postoperative radiotherapy after breast-conserving surgery for early breast cancer,” the investigators wrote in The Lancet Oncology. “These trials showed that radiotherapy reduces the risk of local recurrence but were underpowered individually to detect a difference in overall survival.”
 

How Did the Present Study Increase Our Understanding of the Benefits of Adjuvant Radiotherapy in Early Breast Cancer?

The present analysis included data from a trial that began in 1985, when 589 patients with early breast cancer (tumors ≤ 4 cm [T1 or T2 and N0 or N1]) were randomized to receive either high-dose or no radiotherapy, with final cohorts including 291 patients and 294 patients, respectively. The radiotherapy was given 50 Gy in 20-25 fractions, either locally or locoregionally.

Estrogen receptor (ER)–positive patients (≥ 20 fmol/mg protein) received 5 years of daily oral tamoxifen. ER-poor patients (< 20 fmol/mg protein) received a chemotherapy combination of cyclophosphamide, methotrexate, and fluorouracil on a 21-day cycle for eight cycles.

Considering all data across a median follow-up of 17.5 years, adjuvant radiotherapy appeared to offer benefit, as it was associated with significantly lower ipsilateral breast tumor recurrence (16% vs 36%; hazard ratio [HR], 0.39; P < .0001).

But that tells only part of the story.

The positive impact of radiotherapy persisted for 1 decade (HR, 0.24; P < .0001), but risk beyond this point was no different between groups (HR, 0.98; P = .95).

“[The] benefit of radiotherapy was time dependent,” the investigators noted.

What’s more, median overall survival was no different between those who received radiotherapy and those who did not (18.7 vs 19.2 years; HR, 1.08; log-rank P = .43), and “reassuringly,” omitting radiotherapy did not increase the rate of distant metastasis.
 

How Might These Findings Influence Treatment Planning for Patients With Early Breast Cancer?

“The results can help clinicians to advise patients better about their choice to have radiotherapy or not if they better understand what benefits it does and does not bring,” the investigators wrote. “These results might provide clues perhaps to the biology of radiotherapy benefit, given that it does not prevent late recurrences, suggesting that patients whose biology predicts a late relapse only might not gain a benefit from radiotherapy.”

Gary M. Freedman, MD, chief of Women’s Health Service, Radiation Oncology, at Penn Medicine, Philadelphia, offered a different perspective.

“The study lumps together a local recurrence of breast cancer — that is relapse of the cancer years after treatment with lumpectomy and radiation — with the development of an entirely new breast cancer in the same breast,” Dr. Freedman said in a written comment. “When something comes back between years 0-5 and 0-8, we usually think of it as a true local recurrence arbitrarily, but beyond that they are new cancers.”

He went on to emphasize the clinical importance of reducing local recurrence within the first decade, noting that “this leads to much less morbidity and better quality of life for the patients.”

Dr. Freedman also shared his perspective on the survival data.

“Radiation did reduce breast cancer mortality very significantly — death from breast cancers went down from 46% to 37%,” he wrote (P = .054). “This is on the same level as chemo or hormone therapy. The study was not powered to detect significant differences in survival by radiation, but that has been shown with other meta-analyses.”
 

Are Findings From a Trial Started 30 Years Ago Still Relevant Today?

“Clearly the treatment of early breast cancer has advanced since the 1980s when the Scottish Conservation trial was launched,” study coauthor Ian Kunkler, MB, FRCR, of the University of Edinburgh, said in a written comment. “There is more breast screening, attention to clearing surgical margins of residual disease, more effective and longer periods of adjuvant hormonal therapy, reduced radiotherapy toxicity from more precise delivery. However, most anticancer treatments lose their effectiveness over time.”

He suggested that more trials are needed to confirm the present findings and reiterated that the lack of long-term recurrence benefit is most relevant for patients with disease features that predict late relapse, who “seem to gain little from adjuvant radiotherapy given as part of primary treatment.”

Dr. Kunkler noted that the observed benefit in the first decade supports the continued use of radiotherapy alongside anticancer drug treatment.

When asked the same question, Freedman emphasized the differences in treatment today vs the 1980s.

“The results of modern multidisciplinary cancer care are much, much better than these 30-year results,” Dr. Freedman said. “The risk for local recurrence in the breast after radiation is now about 2%-3% at 10 years in most studies.”

He also noted that modern radiotherapy techniques have “significantly lowered dose and risks to heart and lung,” compared with techniques used 30 years ago.

“A take-home point for the study is after breast conservation, whether or not you have radiation, you have to continue long-term screening mammograms for new breast cancers that may occur even decades later,” Dr. Freedman concluded.
 

How Might These Findings Impact Future Research Design and Funding?

“The findings should encourage trial funders to consider funding long-term follow-up beyond 10 years to assess benefits and risks of anticancer therapies,” Dr. Kunkler said. “The importance of long-term follow-up cannot be understated.”

This study was funded by Breast Cancer Institute (part of Edinburgh and Lothians Health Foundation), PFS Genomics (now part of Exact Sciences), the University of Edinburgh, and NHS Lothian. The investigators reported no conflicts of interest.

A version of this article first appeared on Medscape.com.

TOPLINE:

The use of menopausal hormone therapy (MHT) increases breast cancer risk in women with a strong family history of breast cancer. These women have a striking cumulative risk of developing breast cancer (age, 50-80 years) of 22.4%, according to a new modelling study of UK women.

METHODOLOGY:

This was a modeling study integrating two data-sets of UK women: the BOADICEA dataset of age-specific breast cancer risk with family history and the Collaborative Group on Hormonal Factors in Breast Cancer, which covers relative risk for breast cancer with different types and durations of MHT.

Four different breast cancer family history profiles were:

• “Average” family history of breast cancer has unknown affected family members;
• “Modest” family history comprises a single first-degree relative with breast cancer at the age of 60 years.
• “Intermediate” family history comprises a single first-degree relative who developed breast cancer at the age of 40 years.
• “Strong” family history comprises two first-degree relatives who developed breast cancer at the age of 50 years.

TAKEAWAY:

• The lowest risk category: “Average” family history with no MHT use has a cumulative breast cancer risk (age, 50-80 years) of 9.8% and a risk of dying from breast cancer of 1.7%. These risks rise with 5 years’ exposure to MHT (age, 50-55 years) to 11.0% and 1.8%, respectively.
• The highest risk category: “Strong” family history with no MHT use has a cumulative breast cancer risk (age, 50-80 years) of 19.6% and a risk of dying from breast cancer of 3.2%. These risks rise with 5 years’ exposure to MHT (age, 50-55 years) to 22.4% and 3.5%, respectively.

IN PRACTICE:

The authors concluded that, “These integrated data will enable more accurate estimates of absolute and attributable risk associated with MHT exposure for women with a family history of breast cancer, informing shared decision-making.”

SOURCE:

The lead author is Catherine Huntley of the Institute of Cancer Research, London, England. The study appeared in the British Journal of General Practice.

LIMITATIONS:

Limitations included modeling study that did not directly measure individuals with combined risks.

DISCLOSURES:

The study was funded by several sources including Cancer Research UK. The authors reported no conflicts of interest.

A version of this article first appeared on Medscape.com.

TOPLINE:

The use of menopausal hormone therapy (MHT) increases breast cancer risk in women with a strong family history of breast cancer. These women have a striking cumulative risk of developing breast cancer (age, 50-80 years) of 22.4%, according to a new modelling study of UK women.

METHODOLOGY:

This was a modeling study integrating two data-sets of UK women: the BOADICEA dataset of age-specific breast cancer risk with family history and the Collaborative Group on Hormonal Factors in Breast Cancer, which covers relative risk for breast cancer with different types and durations of MHT.

Four different breast cancer family history profiles were:

• “Average” family history of breast cancer has unknown affected family members;
• “Modest” family history comprises a single first-degree relative with breast cancer at the age of 60 years.
• “Intermediate” family history comprises a single first-degree relative who developed breast cancer at the age of 40 years.
• “Strong” family history comprises two first-degree relatives who developed breast cancer at the age of 50 years.

TAKEAWAY:

• The lowest risk category: “Average” family history with no MHT use has a cumulative breast cancer risk (age, 50-80 years) of 9.8% and a risk of dying from breast cancer of 1.7%. These risks rise with 5 years’ exposure to MHT (age, 50-55 years) to 11.0% and 1.8%, respectively.
• The highest risk category: “Strong” family history with no MHT use has a cumulative breast cancer risk (age, 50-80 years) of 19.6% and a risk of dying from breast cancer of 3.2%. These risks rise with 5 years’ exposure to MHT (age, 50-55 years) to 22.4% and 3.5%, respectively.

IN PRACTICE:

The authors concluded that, “These integrated data will enable more accurate estimates of absolute and attributable risk associated with MHT exposure for women with a family history of breast cancer, informing shared decision-making.”

SOURCE:

The lead author is Catherine Huntley of the Institute of Cancer Research, London, England. The study appeared in the British Journal of General Practice.

LIMITATIONS:

Limitations included modeling study that did not directly measure individuals with combined risks.

DISCLOSURES:

The study was funded by several sources including Cancer Research UK. The authors reported no conflicts of interest.

A version of this article first appeared on Medscape.com.

TOPLINE:

The use of menopausal hormone therapy (MHT) increases breast cancer risk in women with a strong family history of breast cancer. These women have a striking cumulative risk of developing breast cancer (age, 50-80 years) of 22.4%, according to a new modelling study of UK women.

METHODOLOGY:

This was a modeling study integrating two data-sets of UK women: the BOADICEA dataset of age-specific breast cancer risk with family history and the Collaborative Group on Hormonal Factors in Breast Cancer, which covers relative risk for breast cancer with different types and durations of MHT.

Four different breast cancer family history profiles were:

• “Average” family history of breast cancer has unknown affected family members;
• “Modest” family history comprises a single first-degree relative with breast cancer at the age of 60 years.
• “Intermediate” family history comprises a single first-degree relative who developed breast cancer at the age of 40 years.
• “Strong” family history comprises two first-degree relatives who developed breast cancer at the age of 50 years.

TAKEAWAY:

• The lowest risk category: “Average” family history with no MHT use has a cumulative breast cancer risk (age, 50-80 years) of 9.8% and a risk of dying from breast cancer of 1.7%. These risks rise with 5 years’ exposure to MHT (age, 50-55 years) to 11.0% and 1.8%, respectively.
• The highest risk category: “Strong” family history with no MHT use has a cumulative breast cancer risk (age, 50-80 years) of 19.6% and a risk of dying from breast cancer of 3.2%. These risks rise with 5 years’ exposure to MHT (age, 50-55 years) to 22.4% and 3.5%, respectively.

IN PRACTICE:

The authors concluded that, “These integrated data will enable more accurate estimates of absolute and attributable risk associated with MHT exposure for women with a family history of breast cancer, informing shared decision-making.”

SOURCE:

The lead author is Catherine Huntley of the Institute of Cancer Research, London, England. The study appeared in the British Journal of General Practice.

LIMITATIONS:

Limitations included modeling study that did not directly measure individuals with combined risks.

DISCLOSURES:

The study was funded by several sources including Cancer Research UK. The authors reported no conflicts of interest.

A version of this article first appeared on Medscape.com.

TOPLINE:

Hormone-modulating therapy for breast cancer may protect older women from Alzheimer’s disease and related dementias, although the protective effect varies by age and race, with the greatest benefit seen in younger Black women.

METHODOLOGY:

• Hormone-modulating therapy is widely used to treat hormone receptor–positive breast cancer, but the cognitive effects of the treatment, including a potential link to dementia, remain unclear.
• To investigate, researchers used the SEER-Medicare linked database to identify women aged 65 years or older with breast cancer who did and did not receive hormone-modulating therapy within 3 years following their diagnosis.
• The researchers excluded women with preexisting Alzheimer’s disease/dementia diagnoses or those who had received hormone-modulating therapy before their breast cancer diagnosis.
• Analyses were adjusted for demographic, sociocultural, and clinical variables, and subgroup analyses evaluated the impact of age, race, and type of hormone-modulating therapy on Alzheimer’s disease/dementia risk.

TAKEAWAY:

• Among the 18,808 women included in the analysis, 66% received hormone-modulating therapy and 34% did not. During the mean follow-up of 12 years, 24% of hormone-modulating therapy users and 28% of nonusers developed Alzheimer’s disease/dementia.
• Overall, hormone-modulating therapy use (vs nonuse) was associated with a significant 7% lower risk for Alzheimer’s disease/dementia (hazard ratio [HR], 0.93; P = .005), with notable age and racial differences.
• Hormone-modulating therapy use was associated with a 24% lower risk for Alzheimer’s disease/dementia in Black women aged 65-74 years (HR, 0.76), but that protective effect decreased to 19% in Black women aged 75 years or older (HR, 0.81). White women aged 65-74 years who received hormone-modulating therapy (vs those who did not) had an 11% lower risk for Alzheimer’s disease/dementia (HR, 0.89), but the association disappeared among those aged 75 years or older (HR, 0.96; 95% CI, 0.90-1.02). Other races demonstrated no significant association between hormone-modulating therapy use and Alzheimer’s disease/dementia.
• Overall, the use of an aromatase inhibitor or a selective estrogen receptor modulator was associated with a significantly lower risk for Alzheimer’s disease/dementia (HR, 0.93 and HR, 0.89, respectively).

IN PRACTICE:

Overall, the retrospective study found that “hormone therapy was associated with protection against [Alzheimer’s/dementia] in women aged 65 years or older with newly diagnosed breast cancer,” with the decrease in risk relatively greater for Black women and women younger than 75 years, the authors concluded.

“The results highlight the critical need for personalized breast cancer treatment plans that are tailored to the individual characteristics of each patient, particularly given the significantly higher likelihood (two to three times more) of Black women developing [Alzheimer’s/dementia], compared with their White counterparts,” the researchers added.
 

SOURCE:

The study, with first author Chao Cai, PhD, Department of Clinical Pharmacy and Outcomes Sciences, University of South Carolina, Columbia, was published online on July 16 in JAMA Network Open.

LIMITATIONS:

The study included only women aged 65 years or older, limiting generalizability to younger women. The dataset lacked genetic information and laboratory data related to dementia. The duration of hormone-modulating therapy use beyond 3 years and specific formulations were not assessed. Potential confounders such as variations in chemotherapy, radiation, and surgery were not fully addressed.

DISCLOSURES:

Support for the study was provided by the National Institutes of Health; Carolina Center on Alzheimer’s Disease and Minority Research pilot project; and the Dean’s Faculty Advancement Fund, University of Pittsburgh, Pennsylvania. The authors reported no relevant disclosures.

A version of this article first appeared on Medscape.com.

TOPLINE:

Hormone-modulating therapy for breast cancer may protect older women from Alzheimer’s disease and related dementias, although the protective effect varies by age and race, with the greatest benefit seen in younger Black women.

METHODOLOGY:

• Hormone-modulating therapy is widely used to treat hormone receptor–positive breast cancer, but the cognitive effects of the treatment, including a potential link to dementia, remain unclear.
• To investigate, researchers used the SEER-Medicare linked database to identify women aged 65 years or older with breast cancer who did and did not receive hormone-modulating therapy within 3 years following their diagnosis.
• The researchers excluded women with preexisting Alzheimer’s disease/dementia diagnoses or those who had received hormone-modulating therapy before their breast cancer diagnosis.
• Analyses were adjusted for demographic, sociocultural, and clinical variables, and subgroup analyses evaluated the impact of age, race, and type of hormone-modulating therapy on Alzheimer’s disease/dementia risk.

TAKEAWAY:

• Among the 18,808 women included in the analysis, 66% received hormone-modulating therapy and 34% did not. During the mean follow-up of 12 years, 24% of hormone-modulating therapy users and 28% of nonusers developed Alzheimer’s disease/dementia.
• Overall, hormone-modulating therapy use (vs nonuse) was associated with a significant 7% lower risk for Alzheimer’s disease/dementia (hazard ratio [HR], 0.93; P = .005), with notable age and racial differences.
• Hormone-modulating therapy use was associated with a 24% lower risk for Alzheimer’s disease/dementia in Black women aged 65-74 years (HR, 0.76), but that protective effect decreased to 19% in Black women aged 75 years or older (HR, 0.81). White women aged 65-74 years who received hormone-modulating therapy (vs those who did not) had an 11% lower risk for Alzheimer’s disease/dementia (HR, 0.89), but the association disappeared among those aged 75 years or older (HR, 0.96; 95% CI, 0.90-1.02). Other races demonstrated no significant association between hormone-modulating therapy use and Alzheimer’s disease/dementia.
• Overall, the use of an aromatase inhibitor or a selective estrogen receptor modulator was associated with a significantly lower risk for Alzheimer’s disease/dementia (HR, 0.93 and HR, 0.89, respectively).

IN PRACTICE:

Overall, the retrospective study found that “hormone therapy was associated with protection against [Alzheimer’s/dementia] in women aged 65 years or older with newly diagnosed breast cancer,” with the decrease in risk relatively greater for Black women and women younger than 75 years, the authors concluded.

“The results highlight the critical need for personalized breast cancer treatment plans that are tailored to the individual characteristics of each patient, particularly given the significantly higher likelihood (two to three times more) of Black women developing [Alzheimer’s/dementia], compared with their White counterparts,” the researchers added.
 

SOURCE:

The study, with first author Chao Cai, PhD, Department of Clinical Pharmacy and Outcomes Sciences, University of South Carolina, Columbia, was published online on July 16 in JAMA Network Open.

LIMITATIONS:

The study included only women aged 65 years or older, limiting generalizability to younger women. The dataset lacked genetic information and laboratory data related to dementia. The duration of hormone-modulating therapy use beyond 3 years and specific formulations were not assessed. Potential confounders such as variations in chemotherapy, radiation, and surgery were not fully addressed.

DISCLOSURES:

Support for the study was provided by the National Institutes of Health; Carolina Center on Alzheimer’s Disease and Minority Research pilot project; and the Dean’s Faculty Advancement Fund, University of Pittsburgh, Pennsylvania. The authors reported no relevant disclosures.

A version of this article first appeared on Medscape.com.

TOPLINE:

Hormone-modulating therapy for breast cancer may protect older women from Alzheimer’s disease and related dementias, although the protective effect varies by age and race, with the greatest benefit seen in younger Black women.

METHODOLOGY:

• Hormone-modulating therapy is widely used to treat hormone receptor–positive breast cancer, but the cognitive effects of the treatment, including a potential link to dementia, remain unclear.
• To investigate, researchers used the SEER-Medicare linked database to identify women aged 65 years or older with breast cancer who did and did not receive hormone-modulating therapy within 3 years following their diagnosis.
• The researchers excluded women with preexisting Alzheimer’s disease/dementia diagnoses or those who had received hormone-modulating therapy before their breast cancer diagnosis.
• Analyses were adjusted for demographic, sociocultural, and clinical variables, and subgroup analyses evaluated the impact of age, race, and type of hormone-modulating therapy on Alzheimer’s disease/dementia risk.

TAKEAWAY:

• Among the 18,808 women included in the analysis, 66% received hormone-modulating therapy and 34% did not. During the mean follow-up of 12 years, 24% of hormone-modulating therapy users and 28% of nonusers developed Alzheimer’s disease/dementia.
• Overall, hormone-modulating therapy use (vs nonuse) was associated with a significant 7% lower risk for Alzheimer’s disease/dementia (hazard ratio [HR], 0.93; P = .005), with notable age and racial differences.
• Hormone-modulating therapy use was associated with a 24% lower risk for Alzheimer’s disease/dementia in Black women aged 65-74 years (HR, 0.76), but that protective effect decreased to 19% in Black women aged 75 years or older (HR, 0.81). White women aged 65-74 years who received hormone-modulating therapy (vs those who did not) had an 11% lower risk for Alzheimer’s disease/dementia (HR, 0.89), but the association disappeared among those aged 75 years or older (HR, 0.96; 95% CI, 0.90-1.02). Other races demonstrated no significant association between hormone-modulating therapy use and Alzheimer’s disease/dementia.
• Overall, the use of an aromatase inhibitor or a selective estrogen receptor modulator was associated with a significantly lower risk for Alzheimer’s disease/dementia (HR, 0.93 and HR, 0.89, respectively).

IN PRACTICE:

Overall, the retrospective study found that “hormone therapy was associated with protection against [Alzheimer’s/dementia] in women aged 65 years or older with newly diagnosed breast cancer,” with the decrease in risk relatively greater for Black women and women younger than 75 years, the authors concluded.

“The results highlight the critical need for personalized breast cancer treatment plans that are tailored to the individual characteristics of each patient, particularly given the significantly higher likelihood (two to three times more) of Black women developing [Alzheimer’s/dementia], compared with their White counterparts,” the researchers added.
 

SOURCE:

The study, with first author Chao Cai, PhD, Department of Clinical Pharmacy and Outcomes Sciences, University of South Carolina, Columbia, was published online on July 16 in JAMA Network Open.

LIMITATIONS:

The study included only women aged 65 years or older, limiting generalizability to younger women. The dataset lacked genetic information and laboratory data related to dementia. The duration of hormone-modulating therapy use beyond 3 years and specific formulations were not assessed. Potential confounders such as variations in chemotherapy, radiation, and surgery were not fully addressed.

DISCLOSURES:

Support for the study was provided by the National Institutes of Health; Carolina Center on Alzheimer’s Disease and Minority Research pilot project; and the Dean’s Faculty Advancement Fund, University of Pittsburgh, Pennsylvania. The authors reported no relevant disclosures.

A version of this article first appeared on Medscape.com.

TOPLINE:

Women who received false-positive mammography results were less likely to return for future screenings.

METHODOLOGY:

• Researchers analyzed more than three million screening mammograms from more than one million women aged between 40 and 73 years at nearly 200 facilities in the Breast Cancer Surveillance Consortium between 2005 and 2017.
• Mammography results were classified as true negative or false positive; women who received false-positive results were either asked to come back for additional imaging, a short interval follow-up or biopsy recommendations.
• The primary outcome was the probability of returning for routine screening within 9-30 months after a false-positive or true-negative result, adjusted for race, ethnicity, age, and time since the last mammogram.
• Women with two screening mammograms within 5 years were also analyzed to evaluate the probability of returning for a third screening based on combinations of true-negative and false-positive results.

TAKEAWAY:

• Nearly 10.0% (95% CI, 9.1%-10.5%) of women who received screening mammograms got a false-positive result, 5.8% (95% CI, 5.5%-6.2%) of whom needed immediate additional imaging, 2.7% (95% CI, 2.3%-3.2%) needed short-interval follow-up, and 1.3% (95% CI, 1.1%-1.4%) were recommended for a biopsy.
• Women were more likely to return for screening after a true-negative result (76.9%) than after a false positive to obtain more data through additional imaging (72.4%), short-interval follow-ups (54.7%), or biopsy (61.0%).
• Asian and Hispanic/Latinx women who received a false-positive result were much less likely to return for a screening than women of the same groups who received a true-negative result, with recommendations for short interval follow-up (decrease of 20-25 percentage points) or biopsy (decrease of 13-14 percentage points).
• For women who had two screening mammograms within 5 years, receiving a false-positive result on the second was linked to a lower likelihood of returning for a third screening, regardless of results for the first.

IN PRACTICE:

“Physicians should educate their patients about the importance of continued screening after false-positive results, especially given the associated increased future risk for breast cancer,” study authors wrote.

SOURCE:

The study was led by Diana L. Miglioretti, PhD, of the Department of Public Health Sciences at the University of California, Davis, and published online on September 3 in Annals of Internal Medicine.

LIMITATIONS:

Women could receive care at facilities outside of the trial, which may have affected the accuracy of return rates. The study did not track a complete history of false-positive results. The study did not have information about how often physicians recommend screenings and did not account for other health conditions.

DISCLOSURES:

One coauthor reported receiving grants from the National Institutes of Health and the American Cancer Society, as well as consulting fees from the University of Florida, Gainesville.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.

A version of this article first appeared on Medscape.com.

TOPLINE:

Women who received false-positive mammography results were less likely to return for future screenings.

METHODOLOGY:

• Researchers analyzed more than three million screening mammograms from more than one million women aged between 40 and 73 years at nearly 200 facilities in the Breast Cancer Surveillance Consortium between 2005 and 2017.
• Mammography results were classified as true negative or false positive; women who received false-positive results were either asked to come back for additional imaging, a short interval follow-up or biopsy recommendations.
• The primary outcome was the probability of returning for routine screening within 9-30 months after a false-positive or true-negative result, adjusted for race, ethnicity, age, and time since the last mammogram.
• Women with two screening mammograms within 5 years were also analyzed to evaluate the probability of returning for a third screening based on combinations of true-negative and false-positive results.

TAKEAWAY:

• Nearly 10.0% (95% CI, 9.1%-10.5%) of women who received screening mammograms got a false-positive result, 5.8% (95% CI, 5.5%-6.2%) of whom needed immediate additional imaging, 2.7% (95% CI, 2.3%-3.2%) needed short-interval follow-up, and 1.3% (95% CI, 1.1%-1.4%) were recommended for a biopsy.
• Women were more likely to return for screening after a true-negative result (76.9%) than after a false positive to obtain more data through additional imaging (72.4%), short-interval follow-ups (54.7%), or biopsy (61.0%).
• Asian and Hispanic/Latinx women who received a false-positive result were much less likely to return for a screening than women of the same groups who received a true-negative result, with recommendations for short interval follow-up (decrease of 20-25 percentage points) or biopsy (decrease of 13-14 percentage points).
• For women who had two screening mammograms within 5 years, receiving a false-positive result on the second was linked to a lower likelihood of returning for a third screening, regardless of results for the first.

IN PRACTICE:

“Physicians should educate their patients about the importance of continued screening after false-positive results, especially given the associated increased future risk for breast cancer,” study authors wrote.

SOURCE:

The study was led by Diana L. Miglioretti, PhD, of the Department of Public Health Sciences at the University of California, Davis, and published online on September 3 in Annals of Internal Medicine.

LIMITATIONS:

Women could receive care at facilities outside of the trial, which may have affected the accuracy of return rates. The study did not track a complete history of false-positive results. The study did not have information about how often physicians recommend screenings and did not account for other health conditions.

DISCLOSURES:

One coauthor reported receiving grants from the National Institutes of Health and the American Cancer Society, as well as consulting fees from the University of Florida, Gainesville.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.

A version of this article first appeared on Medscape.com.

TOPLINE:

Women who received false-positive mammography results were less likely to return for future screenings.

METHODOLOGY:

• Researchers analyzed more than three million screening mammograms from more than one million women aged between 40 and 73 years at nearly 200 facilities in the Breast Cancer Surveillance Consortium between 2005 and 2017.
• Mammography results were classified as true negative or false positive; women who received false-positive results were either asked to come back for additional imaging, a short interval follow-up or biopsy recommendations.
• The primary outcome was the probability of returning for routine screening within 9-30 months after a false-positive or true-negative result, adjusted for race, ethnicity, age, and time since the last mammogram.
• Women with two screening mammograms within 5 years were also analyzed to evaluate the probability of returning for a third screening based on combinations of true-negative and false-positive results.

TAKEAWAY:

• Nearly 10.0% (95% CI, 9.1%-10.5%) of women who received screening mammograms got a false-positive result, 5.8% (95% CI, 5.5%-6.2%) of whom needed immediate additional imaging, 2.7% (95% CI, 2.3%-3.2%) needed short-interval follow-up, and 1.3% (95% CI, 1.1%-1.4%) were recommended for a biopsy.
• Women were more likely to return for screening after a true-negative result (76.9%) than after a false positive to obtain more data through additional imaging (72.4%), short-interval follow-ups (54.7%), or biopsy (61.0%).
• Asian and Hispanic/Latinx women who received a false-positive result were much less likely to return for a screening than women of the same groups who received a true-negative result, with recommendations for short interval follow-up (decrease of 20-25 percentage points) or biopsy (decrease of 13-14 percentage points).
• For women who had two screening mammograms within 5 years, receiving a false-positive result on the second was linked to a lower likelihood of returning for a third screening, regardless of results for the first.

IN PRACTICE:

“Physicians should educate their patients about the importance of continued screening after false-positive results, especially given the associated increased future risk for breast cancer,” study authors wrote.

SOURCE:

The study was led by Diana L. Miglioretti, PhD, of the Department of Public Health Sciences at the University of California, Davis, and published online on September 3 in Annals of Internal Medicine.

LIMITATIONS:

Women could receive care at facilities outside of the trial, which may have affected the accuracy of return rates. The study did not track a complete history of false-positive results. The study did not have information about how often physicians recommend screenings and did not account for other health conditions.

DISCLOSURES:

One coauthor reported receiving grants from the National Institutes of Health and the American Cancer Society, as well as consulting fees from the University of Florida, Gainesville.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.

A version of this article first appeared on Medscape.com.

Clonal hematopoiesis of indeterminate potential (CHIP) and mosaic chromosomal alterations (mCAs) are associated with an increased risk for breast cancer, and CHIP is associated with increased mortality in patients with colon cancer, according to the authors of new research.

These findings, drawn from almost 11,000 patients in the Women’s Health Initiative (WHI) study, add further evidence that CHIP and mCA drive solid tumor risk, alongside known associations with hematologic malignancies, reported lead author Pinkal Desai, MD, associate professor of medicine and clinical director of molecular aging at Englander Institute for Precision Medicine, Weill Cornell Medical College, New York City, and colleagues.
 

How This Study Differs From Others of Breast Cancer Risk Factors

“The independent effect of CHIP and mCA on risk and mortality from solid tumors has not been elucidated due to lack of detailed data on mortality outcomes and risk factors,” the investigators wrote in Cancer, although some previous studies have suggested a link.

In particular, the investigators highlighted a 2022 UK Biobank study, which reported an association between CHIP and lung cancer and a borderline association with breast cancer that did not quite reach statistical significance.

But the UK Biobank study was confined to a UK population, Dr. Desai noted in an interview, and the data were less detailed than those in the present investigation.

“In terms of risk, the part that was lacking in previous studies was a comprehensive assessment of risk factors that increase risk for all these cancers,” Dr. Desai said. “For example, for breast cancer, we had very detailed data on [participants’] Gail risk score, which is known to impact breast cancer risk. We also had mammogram data and colonoscopy data.”

In an accompanying editorial, Koichi Takahashi, MD, PhD , and Nehali Shah, BS, of The University of Texas MD Anderson Cancer Center, Houston, Texas, pointed out the same UK Biobank findings, then noted that CHIP has also been linked with worse overall survival in unselected cancer patients. Still, they wrote, “the impact of CH on cancer risk and mortality remains controversial due to conflicting data and context‐dependent effects,” necessitating studies like this one by Dr. Desai and colleagues.
 

How Was the Relationship Between CHIP, MCA, and Solid Tumor Risk Assessed?

To explore possible associations between CHIP, mCA, and solid tumors, the investigators analyzed whole genome sequencing data from 10,866 women in the WHI, a multi-study program that began in 1992 and involved 161,808 women in both observational and clinical trial cohorts.

In 2002, the first big data release from the WHI suggested that hormone replacement therapy (HRT) increased breast cancer risk, leading to widespread reduction in HRT use.

More recent reports continue to shape our understanding of these risks, suggesting differences across cancer types. For breast cancer, the WHI data suggested that HRT-associated risk was largely driven by formulations involving progesterone and estrogen, whereas estrogen-only formulations, now more common, are generally considered to present an acceptable risk profile for suitable patients.

The new study accounted for this potential HRT-associated risk, including by adjusting for patients who received HRT, type of HRT received, and duration of HRT received. According to Desai, this approach is commonly used when analyzing data from the WHI, nullifying concerns about the potentially deleterious effects of the hormones used in the study.

“Our question was not ‘does HRT cause cancer?’ ” Dr. Desai said in an interview. “But HRT can be linked to breast cancer risk and has a potential to be a confounder, and hence the above methodology.

“So I can say that the confounding/effect modification that HRT would have contributed to in the relationship between exposure (CH and mCA) and outcome (cancer) is well adjusted for as described above. This is standard in WHI analyses,” she continued.

“Every Women’s Health Initiative analysis that comes out — not just for our study — uses a standard method ... where you account for hormonal therapy,” Dr. Desai added, again noting that many other potential risk factors were considered, enabling a “detailed, robust” analysis.

Dr. Takahashi and Ms. Shah agreed. “A notable strength of this study is its adjustment for many confounding factors,” they wrote. “The cohort’s well‐annotated data on other known cancer risk factors allowed for a robust assessment of CH’s independent risk.”
 

How Do Findings Compare With Those of the UK Biobank Study?

CHIP was associated with a 30% increased risk for breast cancer (hazard ratio [HR], 1.30; 95% CI, 1.03-1.64; P = .02), strengthening the borderline association reported by the UK Biobank study.

In contrast with the UK Biobank study, CHIP was not associated with lung cancer risk, although this may have been caused by fewer cases of lung cancer and a lack of male patients, Dr. Desai suggested.

“The discrepancy between the studies lies in the risk of lung cancer, although the point estimate in the current study suggested a positive association,” wrote Dr. Takahashi and Ms. Shah.

As in the UK Biobank study, CHIP was not associated with increased risk of developing colorectal cancer.

Mortality analysis, however, which was not conducted in the UK Biobank study, offered a new insight: Patients with existing colorectal cancer and CHIP had a significantly higher mortality risk than those without CHIP. Before stage adjustment, risk for mortality among those with colorectal cancer and CHIP was fourfold higher than those without CHIP (HR, 3.99; 95% CI, 2.41-6.62; P < .001). After stage adjustment, CHIP was still associated with a twofold higher mortality risk (HR, 2.50; 95% CI, 1.32-4.72; P = .004).

The investigators’ first mCA analyses, which employed a cell fraction cutoff greater than 3%, were unfruitful. But raising the cell fraction threshold to 5% in an exploratory analysis showed that autosomal mCA was associated with a 39% increased risk for breast cancer (HR, 1.39; 95% CI, 1.06-1.83; P = .01). No such associations were found between mCA and colorectal or lung cancer, regardless of cell fraction threshold.

The original 3% cell fraction threshold was selected on the basis of previous studies reporting a link between mCA and hematologic malignancies at this cutoff, Dr. Desai said.

She and her colleagues said a higher 5% cutoff might be needed, as they suspected that the link between mCA and solid tumors may not be causal, requiring a higher mutation rate.
 

Why Do Results Differ Between These Types of Studies?

Dr. Takahashi and Ms. Shah suggested that one possible limitation of the new study, and an obstacle to comparing results with the UK Biobank study and others like it, goes beyond population heterogeneity; incongruent findings could also be explained by differences in whole genome sequencing (WGS) technique.

“Although WGS allows sensitive detection of mCA through broad genomic coverage, it is less effective at detecting CHIP with low variant allele frequency (VAF) due to its relatively shallow depth (30x),” they wrote. “Consequently, the prevalence of mCA (18.8%) was much higher than that of CHIP (8.3%) in this cohort, contrasting with other studies using deeper sequencing.” As a result, the present study may have underestimated CHIP prevalence because of shallow sequencing depth.

“This inconsistency is a common challenge in CH population studies due to the lack of standardized methodologies and the frequent reliance on preexisting data not originally intended for CH detection,” Dr. Takahashi and Ms. Shah said.

Even so, despite the “heavily context-dependent” nature of these reported risks, the body of evidence to date now offers a convincing biological rationale linking CH with cancer development and outcomes, they added.
 

How Do the CHIP- and mCA-associated Risks Differ Between Solid Tumors and Blood Cancers?

“[These solid tumor risks are] not causal in the way CHIP mutations are causal for blood cancers,” Dr. Desai said. “Here we are talking about solid tumor risk, and it’s kind of scattered. It’s not just breast cancer ... there’s also increased colon cancer mortality. So I feel these mutations are doing something different ... they are sort of an added factor.”

Specific mechanisms remain unclear, Dr. Desai said, although she speculated about possible impacts on the inflammatory state or alterations to the tumor microenvironment.

“These are blood cells, right?” Dr. Desai asked. “They’re everywhere, and they’re changing something inherently in these tumors.”
 

Future research and therapeutic development

Siddhartha Jaiswal, MD, PhD, assistant professor in the Department of Pathology at Stanford University in California, whose lab focuses on clonal hematopoiesis, said the causality question is central to future research.

“The key question is, are these mutations acting because they alter the function of blood cells in some way to promote cancer risk, or is it reflective of some sort of shared etiology that’s not causal?” Dr. Jaiswal said in an interview.

Available data support both possibilities.

On one side, “reasonable evidence” supports the noncausal view, Dr. Jaiswal noted, because telomere length is one of the most common genetic risk factors for clonal hematopoiesis and also for solid tumors, suggesting a shared genetic factor. On the other hand, CHIP and mCA could be directly protumorigenic via conferred disturbances of immune cell function.

When asked if both causal and noncausal factors could be at play, Dr. Jaiswal said, “yeah, absolutely.”

The presence of a causal association could be promising from a therapeutic standpoint.

“If it turns out that this association is driven by a direct causal effect of the mutations, perhaps related to immune cell function or dysfunction, then targeting that dysfunction could be a therapeutic path to improve outcomes in people, and there’s a lot of interest in this,” Dr. Jaiswal said. He went on to explain how a trial exploring this approach via interleukin-8 inhibition in lung cancer fell short.

Yet earlier intervention may still hold promise, according to experts.

“[This study] provokes the hypothesis that CH‐targeted interventions could potentially reduce cancer risk in the future,” Dr. Takahashi and Ms. Shah said in their editorial.

The WHI program is funded by the National Heart, Lung, and Blood Institute; National Institutes of Health; and the Department of Health & Human Services. The investigators disclosed relationships with Eli Lilly, AbbVie, Celgene, and others. Dr. Jaiswal reported stock equity in a company that has an interest in clonal hematopoiesis.

A version of this article first appeared on Medscape.com.

Clonal hematopoiesis of indeterminate potential (CHIP) and mosaic chromosomal alterations (mCAs) are associated with an increased risk for breast cancer, and CHIP is associated with increased mortality in patients with colon cancer, according to the authors of new research.

These findings, drawn from almost 11,000 patients in the Women’s Health Initiative (WHI) study, add further evidence that CHIP and mCA drive solid tumor risk, alongside known associations with hematologic malignancies, reported lead author Pinkal Desai, MD, associate professor of medicine and clinical director of molecular aging at Englander Institute for Precision Medicine, Weill Cornell Medical College, New York City, and colleagues.
 

How This Study Differs From Others of Breast Cancer Risk Factors

“The independent effect of CHIP and mCA on risk and mortality from solid tumors has not been elucidated due to lack of detailed data on mortality outcomes and risk factors,” the investigators wrote in Cancer, although some previous studies have suggested a link.

In particular, the investigators highlighted a 2022 UK Biobank study, which reported an association between CHIP and lung cancer and a borderline association with breast cancer that did not quite reach statistical significance.

But the UK Biobank study was confined to a UK population, Dr. Desai noted in an interview, and the data were less detailed than those in the present investigation.

“In terms of risk, the part that was lacking in previous studies was a comprehensive assessment of risk factors that increase risk for all these cancers,” Dr. Desai said. “For example, for breast cancer, we had very detailed data on [participants’] Gail risk score, which is known to impact breast cancer risk. We also had mammogram data and colonoscopy data.”

In an accompanying editorial, Koichi Takahashi, MD, PhD , and Nehali Shah, BS, of The University of Texas MD Anderson Cancer Center, Houston, Texas, pointed out the same UK Biobank findings, then noted that CHIP has also been linked with worse overall survival in unselected cancer patients. Still, they wrote, “the impact of CH on cancer risk and mortality remains controversial due to conflicting data and context‐dependent effects,” necessitating studies like this one by Dr. Desai and colleagues.
 

How Was the Relationship Between CHIP, MCA, and Solid Tumor Risk Assessed?

To explore possible associations between CHIP, mCA, and solid tumors, the investigators analyzed whole genome sequencing data from 10,866 women in the WHI, a multi-study program that began in 1992 and involved 161,808 women in both observational and clinical trial cohorts.

In 2002, the first big data release from the WHI suggested that hormone replacement therapy (HRT) increased breast cancer risk, leading to widespread reduction in HRT use.

More recent reports continue to shape our understanding of these risks, suggesting differences across cancer types. For breast cancer, the WHI data suggested that HRT-associated risk was largely driven by formulations involving progesterone and estrogen, whereas estrogen-only formulations, now more common, are generally considered to present an acceptable risk profile for suitable patients.

The new study accounted for this potential HRT-associated risk, including by adjusting for patients who received HRT, type of HRT received, and duration of HRT received. According to Desai, this approach is commonly used when analyzing data from the WHI, nullifying concerns about the potentially deleterious effects of the hormones used in the study.

“Our question was not ‘does HRT cause cancer?’ ” Dr. Desai said in an interview. “But HRT can be linked to breast cancer risk and has a potential to be a confounder, and hence the above methodology.

“So I can say that the confounding/effect modification that HRT would have contributed to in the relationship between exposure (CH and mCA) and outcome (cancer) is well adjusted for as described above. This is standard in WHI analyses,” she continued.

“Every Women’s Health Initiative analysis that comes out — not just for our study — uses a standard method ... where you account for hormonal therapy,” Dr. Desai added, again noting that many other potential risk factors were considered, enabling a “detailed, robust” analysis.

Dr. Takahashi and Ms. Shah agreed. “A notable strength of this study is its adjustment for many confounding factors,” they wrote. “The cohort’s well‐annotated data on other known cancer risk factors allowed for a robust assessment of CH’s independent risk.”
 

How Do Findings Compare With Those of the UK Biobank Study?

CHIP was associated with a 30% increased risk for breast cancer (hazard ratio [HR], 1.30; 95% CI, 1.03-1.64; P = .02), strengthening the borderline association reported by the UK Biobank study.

In contrast with the UK Biobank study, CHIP was not associated with lung cancer risk, although this may have been caused by fewer cases of lung cancer and a lack of male patients, Dr. Desai suggested.

“The discrepancy between the studies lies in the risk of lung cancer, although the point estimate in the current study suggested a positive association,” wrote Dr. Takahashi and Ms. Shah.

As in the UK Biobank study, CHIP was not associated with increased risk of developing colorectal cancer.

Mortality analysis, however, which was not conducted in the UK Biobank study, offered a new insight: Patients with existing colorectal cancer and CHIP had a significantly higher mortality risk than those without CHIP. Before stage adjustment, risk for mortality among those with colorectal cancer and CHIP was fourfold higher than those without CHIP (HR, 3.99; 95% CI, 2.41-6.62; P < .001). After stage adjustment, CHIP was still associated with a twofold higher mortality risk (HR, 2.50; 95% CI, 1.32-4.72; P = .004).

The investigators’ first mCA analyses, which employed a cell fraction cutoff greater than 3%, were unfruitful. But raising the cell fraction threshold to 5% in an exploratory analysis showed that autosomal mCA was associated with a 39% increased risk for breast cancer (HR, 1.39; 95% CI, 1.06-1.83; P = .01). No such associations were found between mCA and colorectal or lung cancer, regardless of cell fraction threshold.

The original 3% cell fraction threshold was selected on the basis of previous studies reporting a link between mCA and hematologic malignancies at this cutoff, Dr. Desai said.

She and her colleagues said a higher 5% cutoff might be needed, as they suspected that the link between mCA and solid tumors may not be causal, requiring a higher mutation rate.
 

Why Do Results Differ Between These Types of Studies?

Dr. Takahashi and Ms. Shah suggested that one possible limitation of the new study, and an obstacle to comparing results with the UK Biobank study and others like it, goes beyond population heterogeneity; incongruent findings could also be explained by differences in whole genome sequencing (WGS) technique.

“Although WGS allows sensitive detection of mCA through broad genomic coverage, it is less effective at detecting CHIP with low variant allele frequency (VAF) due to its relatively shallow depth (30x),” they wrote. “Consequently, the prevalence of mCA (18.8%) was much higher than that of CHIP (8.3%) in this cohort, contrasting with other studies using deeper sequencing.” As a result, the present study may have underestimated CHIP prevalence because of shallow sequencing depth.

“This inconsistency is a common challenge in CH population studies due to the lack of standardized methodologies and the frequent reliance on preexisting data not originally intended for CH detection,” Dr. Takahashi and Ms. Shah said.

Even so, despite the “heavily context-dependent” nature of these reported risks, the body of evidence to date now offers a convincing biological rationale linking CH with cancer development and outcomes, they added.
 

How Do the CHIP- and mCA-associated Risks Differ Between Solid Tumors and Blood Cancers?

“[These solid tumor risks are] not causal in the way CHIP mutations are causal for blood cancers,” Dr. Desai said. “Here we are talking about solid tumor risk, and it’s kind of scattered. It’s not just breast cancer ... there’s also increased colon cancer mortality. So I feel these mutations are doing something different ... they are sort of an added factor.”

Specific mechanisms remain unclear, Dr. Desai said, although she speculated about possible impacts on the inflammatory state or alterations to the tumor microenvironment.

“These are blood cells, right?” Dr. Desai asked. “They’re everywhere, and they’re changing something inherently in these tumors.”
 

Future research and therapeutic development

Siddhartha Jaiswal, MD, PhD, assistant professor in the Department of Pathology at Stanford University in California, whose lab focuses on clonal hematopoiesis, said the causality question is central to future research.

“The key question is, are these mutations acting because they alter the function of blood cells in some way to promote cancer risk, or is it reflective of some sort of shared etiology that’s not causal?” Dr. Jaiswal said in an interview.

Available data support both possibilities.

On one side, “reasonable evidence” supports the noncausal view, Dr. Jaiswal noted, because telomere length is one of the most common genetic risk factors for clonal hematopoiesis and also for solid tumors, suggesting a shared genetic factor. On the other hand, CHIP and mCA could be directly protumorigenic via conferred disturbances of immune cell function.

When asked if both causal and noncausal factors could be at play, Dr. Jaiswal said, “yeah, absolutely.”

The presence of a causal association could be promising from a therapeutic standpoint.

“If it turns out that this association is driven by a direct causal effect of the mutations, perhaps related to immune cell function or dysfunction, then targeting that dysfunction could be a therapeutic path to improve outcomes in people, and there’s a lot of interest in this,” Dr. Jaiswal said. He went on to explain how a trial exploring this approach via interleukin-8 inhibition in lung cancer fell short.

Yet earlier intervention may still hold promise, according to experts.

“[This study] provokes the hypothesis that CH‐targeted interventions could potentially reduce cancer risk in the future,” Dr. Takahashi and Ms. Shah said in their editorial.

The WHI program is funded by the National Heart, Lung, and Blood Institute; National Institutes of Health; and the Department of Health & Human Services. The investigators disclosed relationships with Eli Lilly, AbbVie, Celgene, and others. Dr. Jaiswal reported stock equity in a company that has an interest in clonal hematopoiesis.

A version of this article first appeared on Medscape.com.

Clonal hematopoiesis of indeterminate potential (CHIP) and mosaic chromosomal alterations (mCAs) are associated with an increased risk for breast cancer, and CHIP is associated with increased mortality in patients with colon cancer, according to the authors of new research.

These findings, drawn from almost 11,000 patients in the Women’s Health Initiative (WHI) study, add further evidence that CHIP and mCA drive solid tumor risk, alongside known associations with hematologic malignancies, reported lead author Pinkal Desai, MD, associate professor of medicine and clinical director of molecular aging at Englander Institute for Precision Medicine, Weill Cornell Medical College, New York City, and colleagues.
 

How This Study Differs From Others of Breast Cancer Risk Factors

“The independent effect of CHIP and mCA on risk and mortality from solid tumors has not been elucidated due to lack of detailed data on mortality outcomes and risk factors,” the investigators wrote in Cancer, although some previous studies have suggested a link.

In particular, the investigators highlighted a 2022 UK Biobank study, which reported an association between CHIP and lung cancer and a borderline association with breast cancer that did not quite reach statistical significance.

But the UK Biobank study was confined to a UK population, Dr. Desai noted in an interview, and the data were less detailed than those in the present investigation.

“In terms of risk, the part that was lacking in previous studies was a comprehensive assessment of risk factors that increase risk for all these cancers,” Dr. Desai said. “For example, for breast cancer, we had very detailed data on [participants’] Gail risk score, which is known to impact breast cancer risk. We also had mammogram data and colonoscopy data.”

In an accompanying editorial, Koichi Takahashi, MD, PhD , and Nehali Shah, BS, of The University of Texas MD Anderson Cancer Center, Houston, Texas, pointed out the same UK Biobank findings, then noted that CHIP has also been linked with worse overall survival in unselected cancer patients. Still, they wrote, “the impact of CH on cancer risk and mortality remains controversial due to conflicting data and context‐dependent effects,” necessitating studies like this one by Dr. Desai and colleagues.
 

How Was the Relationship Between CHIP, MCA, and Solid Tumor Risk Assessed?

To explore possible associations between CHIP, mCA, and solid tumors, the investigators analyzed whole genome sequencing data from 10,866 women in the WHI, a multi-study program that began in 1992 and involved 161,808 women in both observational and clinical trial cohorts.

In 2002, the first big data release from the WHI suggested that hormone replacement therapy (HRT) increased breast cancer risk, leading to widespread reduction in HRT use.

More recent reports continue to shape our understanding of these risks, suggesting differences across cancer types. For breast cancer, the WHI data suggested that HRT-associated risk was largely driven by formulations involving progesterone and estrogen, whereas estrogen-only formulations, now more common, are generally considered to present an acceptable risk profile for suitable patients.

The new study accounted for this potential HRT-associated risk, including by adjusting for patients who received HRT, type of HRT received, and duration of HRT received. According to Desai, this approach is commonly used when analyzing data from the WHI, nullifying concerns about the potentially deleterious effects of the hormones used in the study.

“Our question was not ‘does HRT cause cancer?’ ” Dr. Desai said in an interview. “But HRT can be linked to breast cancer risk and has a potential to be a confounder, and hence the above methodology.

“So I can say that the confounding/effect modification that HRT would have contributed to in the relationship between exposure (CH and mCA) and outcome (cancer) is well adjusted for as described above. This is standard in WHI analyses,” she continued.

“Every Women’s Health Initiative analysis that comes out — not just for our study — uses a standard method ... where you account for hormonal therapy,” Dr. Desai added, again noting that many other potential risk factors were considered, enabling a “detailed, robust” analysis.

Dr. Takahashi and Ms. Shah agreed. “A notable strength of this study is its adjustment for many confounding factors,” they wrote. “The cohort’s well‐annotated data on other known cancer risk factors allowed for a robust assessment of CH’s independent risk.”
 

How Do Findings Compare With Those of the UK Biobank Study?

CHIP was associated with a 30% increased risk for breast cancer (hazard ratio [HR], 1.30; 95% CI, 1.03-1.64; P = .02), strengthening the borderline association reported by the UK Biobank study.

In contrast with the UK Biobank study, CHIP was not associated with lung cancer risk, although this may have been caused by fewer cases of lung cancer and a lack of male patients, Dr. Desai suggested.

“The discrepancy between the studies lies in the risk of lung cancer, although the point estimate in the current study suggested a positive association,” wrote Dr. Takahashi and Ms. Shah.

As in the UK Biobank study, CHIP was not associated with increased risk of developing colorectal cancer.

Mortality analysis, however, which was not conducted in the UK Biobank study, offered a new insight: Patients with existing colorectal cancer and CHIP had a significantly higher mortality risk than those without CHIP. Before stage adjustment, risk for mortality among those with colorectal cancer and CHIP was fourfold higher than those without CHIP (HR, 3.99; 95% CI, 2.41-6.62; P < .001). After stage adjustment, CHIP was still associated with a twofold higher mortality risk (HR, 2.50; 95% CI, 1.32-4.72; P = .004).

The investigators’ first mCA analyses, which employed a cell fraction cutoff greater than 3%, were unfruitful. But raising the cell fraction threshold to 5% in an exploratory analysis showed that autosomal mCA was associated with a 39% increased risk for breast cancer (HR, 1.39; 95% CI, 1.06-1.83; P = .01). No such associations were found between mCA and colorectal or lung cancer, regardless of cell fraction threshold.

The original 3% cell fraction threshold was selected on the basis of previous studies reporting a link between mCA and hematologic malignancies at this cutoff, Dr. Desai said.

She and her colleagues said a higher 5% cutoff might be needed, as they suspected that the link between mCA and solid tumors may not be causal, requiring a higher mutation rate.
 

Why Do Results Differ Between These Types of Studies?

Dr. Takahashi and Ms. Shah suggested that one possible limitation of the new study, and an obstacle to comparing results with the UK Biobank study and others like it, goes beyond population heterogeneity; incongruent findings could also be explained by differences in whole genome sequencing (WGS) technique.

“Although WGS allows sensitive detection of mCA through broad genomic coverage, it is less effective at detecting CHIP with low variant allele frequency (VAF) due to its relatively shallow depth (30x),” they wrote. “Consequently, the prevalence of mCA (18.8%) was much higher than that of CHIP (8.3%) in this cohort, contrasting with other studies using deeper sequencing.” As a result, the present study may have underestimated CHIP prevalence because of shallow sequencing depth.

“This inconsistency is a common challenge in CH population studies due to the lack of standardized methodologies and the frequent reliance on preexisting data not originally intended for CH detection,” Dr. Takahashi and Ms. Shah said.

Even so, despite the “heavily context-dependent” nature of these reported risks, the body of evidence to date now offers a convincing biological rationale linking CH with cancer development and outcomes, they added.
 

How Do the CHIP- and mCA-associated Risks Differ Between Solid Tumors and Blood Cancers?

“[These solid tumor risks are] not causal in the way CHIP mutations are causal for blood cancers,” Dr. Desai said. “Here we are talking about solid tumor risk, and it’s kind of scattered. It’s not just breast cancer ... there’s also increased colon cancer mortality. So I feel these mutations are doing something different ... they are sort of an added factor.”

Specific mechanisms remain unclear, Dr. Desai said, although she speculated about possible impacts on the inflammatory state or alterations to the tumor microenvironment.

“These are blood cells, right?” Dr. Desai asked. “They’re everywhere, and they’re changing something inherently in these tumors.”
 

Future research and therapeutic development

Siddhartha Jaiswal, MD, PhD, assistant professor in the Department of Pathology at Stanford University in California, whose lab focuses on clonal hematopoiesis, said the causality question is central to future research.

“The key question is, are these mutations acting because they alter the function of blood cells in some way to promote cancer risk, or is it reflective of some sort of shared etiology that’s not causal?” Dr. Jaiswal said in an interview.

Available data support both possibilities.

On one side, “reasonable evidence” supports the noncausal view, Dr. Jaiswal noted, because telomere length is one of the most common genetic risk factors for clonal hematopoiesis and also for solid tumors, suggesting a shared genetic factor. On the other hand, CHIP and mCA could be directly protumorigenic via conferred disturbances of immune cell function.

When asked if both causal and noncausal factors could be at play, Dr. Jaiswal said, “yeah, absolutely.”

The presence of a causal association could be promising from a therapeutic standpoint.

“If it turns out that this association is driven by a direct causal effect of the mutations, perhaps related to immune cell function or dysfunction, then targeting that dysfunction could be a therapeutic path to improve outcomes in people, and there’s a lot of interest in this,” Dr. Jaiswal said. He went on to explain how a trial exploring this approach via interleukin-8 inhibition in lung cancer fell short.

Yet earlier intervention may still hold promise, according to experts.

“[This study] provokes the hypothesis that CH‐targeted interventions could potentially reduce cancer risk in the future,” Dr. Takahashi and Ms. Shah said in their editorial.

The WHI program is funded by the National Heart, Lung, and Blood Institute; National Institutes of Health; and the Department of Health & Human Services. The investigators disclosed relationships with Eli Lilly, AbbVie, Celgene, and others. Dr. Jaiswal reported stock equity in a company that has an interest in clonal hematopoiesis.

A version of this article first appeared on Medscape.com.