CNS/Brain Cancer

According to the Centers for Disease Control and Prevention (CDC), over 684,000 Americans are diagnosed with an “obesity-associated” cancer each year.

The incidence of many of these cancers has been rising in recent years, particularly among younger people — a trend that sits in contrast with the overall decline in cancers with no established relationship to excess weight, such as lung and skin cancers. 

Is obesity the new smoking? Not exactly.

Tracing a direct line between excess fat and cancer is much less clear-cut than it is with tobacco. While about 42% of cancers — including common ones such as colorectal and postmenopausal breast cancers — are considered obesity-related, only about 8% of incident cancers are attributed to excess body weight. People often develop those diseases regardless of weight.

Although plenty of evidence points to excess body fat as a cancer risk factor, it’s unclear at what point excess weight has an effect. Is gaining weight later in life, for instance, better or worse for cancer risk than being overweight or obese from a young age?

There’s another glaring knowledge gap: Does losing weight at some point in adulthood change the picture? In other words, how many of those 684,000 diagnoses might have been prevented if people shed excess pounds?

When it comes to weight and cancer risk, “there’s a lot we don’t know,” said Jennifer W. Bea, PhD, associate professor, health promotion sciences, University of Arizona, Tucson.

A Consistent but Complicated Relationship

Given the growing incidence of obesity — which currently affects about 42% of US adults and 20% of children and teenagers — it’s no surprise that many studies have delved into the potential effects of excess weight on cancer rates.

Although virtually all the evidence comes from large cohort studies, leaving the cause-effect question open, certain associations keep showing up.

“What we know is that, consistently, a higher body mass index [BMI] — particularly in the obese category — leads to a higher risk of multiple cancers,” said Jeffrey A. Meyerhardt, MD, MPH, codirector, Colon and Rectal Cancer Center, Dana-Farber Cancer Institute, Boston.

In a widely cited report published in The New England Journal of Medicine in 2016, the International Agency for Research on Cancer (IARC) analyzed over 1000 epidemiologic studies on body fat and cancer. The agency pointed to over a dozen cancers, including some of the most common and deadly, linked to excess body weight.

That list includes esophageal adenocarcinoma and endometrial cancer — associated with the highest risk — along with kidney, liver, stomach (gastric cardia), pancreatic, colorectal, postmenopausal breast, gallbladder, ovarian, and thyroid cancers, plus multiple myeloma and meningioma. There’s also “limited” evidence linking excess weight to additional cancer types, including aggressive prostate cancer and certain head and neck cancers.

At the same time, Dr. Meyerhardt said, many of those same cancers are also associated with issues that lead to, or coexist with, overweight and obesity, including poor diet, lack of exercise, and metabolic conditions such as diabetes. 

It’s a complicated web, and it’s likely, Dr. Meyerhardt said, that high BMI both directly affects cancer risk and is part of a “causal pathway” of other factors that do.

Regarding direct effects, preclinical research has pointed to multiple ways in which excess body fat could contribute to cancer, said Karen M. Basen-Engquist, PhD, MPH, professor, Division of Cancer Prevention and Population Services, The University of Texas MD Anderson Cancer Center, Houston.

One broad mechanism to help explain the obesity-cancer link is chronic systemic inflammation because excess fat tissue can raise levels of substances in the body, such as tumor necrosis factor alpha and interleukin 6, which fuel inflammation. Excess fat also contributes to hyperinsulinemia — too much insulin in the blood — which can help promote the growth and spread of tumor cells. 

But the underlying reasons also appear to vary by cancer type, Dr. Basen-Engquist said. With hormonally driven cancer types, such as breast and endometrial, excess body fat may alter hormone levels in ways that spur tumor growth. Extra fat tissue may, for example, convert androgens into estrogens, which could help feed estrogen-dependent tumors.

That, Dr. Basen-Engquist noted, could be why excess weight is associated with postmenopausal, not premenopausal, breast cancer: Before menopause, body fat is a relatively minor contributor to estrogen levels but becomes more important after menopause.

How Big Is the Effect?

While more than a dozen cancers have been consistently linked to excess weight, the strength of those associations varies considerably. 

Endometrial and esophageal cancers are two that stand out. In the 2016 IARC analysis, people with severe obesity had a seven-times greater risk for endometrial cancer and 4.8-times greater risk for esophageal adenocarcinoma vs people with a normal BMI.

With other cancers, the risk increases for those with severe obesity compared with a normal BMI were far more modest: 10% for ovarian cancer, 30% for colorectal cancer, and 80% for kidney and stomach cancers, for example. For postmenopausal breast cancer, every five-unit increase in BMI was associated with a 10% relative risk increase.

A 2018 study from the American Cancer Society, which attempted to estimate the proportion of cancers in the United States attributable to modifiable risk factors — including alcohol consumption, ultraviolet rays exposure, and physical inactivity — found that smoking accounted for the highest proportion of cancer cases by a wide margin (19%), but excess weight came in second (7.8%).

Again, weight appeared to play a bigger role in certain cancers than others: An estimated 60% of endometrial cancers were linked to excess weight, as were roughly one third of esophageal, kidney, and liver cancers. At the other end of the spectrum, just over 11% of breast, 5% of colorectal, and 4% of ovarian cancers were attributable to excess weight.

Even at the lower end, those rates could make a big difference on the population level, especially for groups with higher rates of obesity.

CDC data show that obesity-related cancers are rising among women younger than 50 years, most rapidly among Hispanic women, and some less common obesity-related cancers, such as stomach, thyroid and pancreatic, are also rising among Black individuals and Hispanic Americans.

Obesity may be one reason for growing cancer disparities, said Leah Ferrucci, PhD, MPH, assistant professor, epidemiology, Yale School of Public Health, New Haven, Connecticut. But, she added, the evidence is limited because Black individuals and Hispanic Americans are understudied.

When Do Extra Pounds Matter?

When it comes to cancer risk, at what point in life does excess weight, or weight gain, matter? Is the standard weight gain in middle age, for instance, as hazardous as being overweight or obese from a young age?

Some evidence suggests there’s no “safe” time for putting on excess pounds.

A recent meta-analysis concluded that weight gain at any point after age 18 years is associated with incremental increases in the risk for postmenopausal breast cancer. A 2023 study in JAMA Network Open found a similar pattern with colorectal and other gastrointestinal cancers: People who had sustained overweight or obesity from age 20 years through middle age faced an increased risk of developing those cancers after age 55 years. 

The timing of weight gain didn’t seem to matter either. The same elevated risk held among people who were normal weight in their younger years but became overweight after age 55 years.

Those studies focused on later-onset disease. But, in recent years, experts have tracked a troubling rise in early-onset cancers — those diagnosed before age 50 years — particularly gastrointestinal cancers. 

An obvious question, Dr. Meyerhardt said, is whether the growing prevalence of obesity among young people is partly to blame.

There’s some data to support that, he said. An analysis from the Nurses’ Health Study II found that women with obesity had double the risk for early-onset colorectal cancer as those with a normal BMI. And every 5-kg increase in weight after age 18 years was associated with a 9% increase in colorectal cancer risk.

But while obesity trends probably partly explain the rise in early-onset cancers, there is likely more to the story, Dr. Meyerhardt said.

“I think all of us who see an increasing number of patients under 50 with colorectal cancer know there’s a fair number who do not fit that [high BMI] profile,” he said. “There’s a fair number over 50 who don’t either.”

Does Weight Loss Help?

With all the evidence pointing to high BMI as a cancer risk factor, a logical conclusion is that weight loss should reduce that excess risk. However, Dr. Bea said, there’s actually little data to support that, and what exists comes from observational studies.

Some research has focused on people who had substantial weight loss after bariatric surgery, with encouraging results. A study published in JAMA found that among 5053 people who underwent bariatric surgery, 2.9% developed an obesity-related cancer over 10 years compared with 4.9% in the nonsurgery group.

Most people, however, aim for less dramatic weight loss, with the help of diet and exercise or sometimes medication. Some evidence shows that a modest degree of weight loss may lower the risks for postmenopausal breast and endometrial cancers. 

A 2020 pooled analysis found, for instance, that among women aged ≥ 50 years, those who lost as little as 2.0-4.5 kg, or 4.4-10.0 pounds, and kept it off for 10 years had a lower risk for breast cancer than women whose weight remained stable. And losing more weight — 9 kg, or about 20 pounds, or more — was even better for lowering cancer risk.

But other research suggests the opposite. A recent analysis found that people who lost weight within the past 2 years through diet and exercise had a higher risk for a range of cancers compared with those who did not lose weight. Overall, though, the increased risk was quite low.

Whatever the research does, or doesn’t, show about weight and cancer risk, Dr. Basen-Engquist said, it’s important that risk factors, obesity and otherwise, aren’t “used as blame tools.”

“With obesity, behavior certainly plays into it,” she said. “But there are so many influences on our behavior that are socially determined.”

Both Dr. Basen-Engquist and Dr. Meyerhardt said it’s important for clinicians to consider the individual in front of them and for everyone to set realistic expectations. 

People with obesity should not feel they have to become thin to be healthier, and no one has to leap from being sedentary to exercising several hours a week. 

“We don’t want patients to feel that if they don’t get to a stated goal in a guideline, it’s all for naught,” Dr. Meyerhardt said.

A version of this article appeared on Medscape.com.

According to the Centers for Disease Control and Prevention (CDC), over 684,000 Americans are diagnosed with an “obesity-associated” cancer each year.

The incidence of many of these cancers has been rising in recent years, particularly among younger people — a trend that sits in contrast with the overall decline in cancers with no established relationship to excess weight, such as lung and skin cancers. 

Is obesity the new smoking? Not exactly.

Tracing a direct line between excess fat and cancer is much less clear-cut than it is with tobacco. While about 42% of cancers — including common ones such as colorectal and postmenopausal breast cancers — are considered obesity-related, only about 8% of incident cancers are attributed to excess body weight. People often develop those diseases regardless of weight.

Although plenty of evidence points to excess body fat as a cancer risk factor, it’s unclear at what point excess weight has an effect. Is gaining weight later in life, for instance, better or worse for cancer risk than being overweight or obese from a young age?

There’s another glaring knowledge gap: Does losing weight at some point in adulthood change the picture? In other words, how many of those 684,000 diagnoses might have been prevented if people shed excess pounds?

When it comes to weight and cancer risk, “there’s a lot we don’t know,” said Jennifer W. Bea, PhD, associate professor, health promotion sciences, University of Arizona, Tucson.

A Consistent but Complicated Relationship

Given the growing incidence of obesity — which currently affects about 42% of US adults and 20% of children and teenagers — it’s no surprise that many studies have delved into the potential effects of excess weight on cancer rates.

Although virtually all the evidence comes from large cohort studies, leaving the cause-effect question open, certain associations keep showing up.

“What we know is that, consistently, a higher body mass index [BMI] — particularly in the obese category — leads to a higher risk of multiple cancers,” said Jeffrey A. Meyerhardt, MD, MPH, codirector, Colon and Rectal Cancer Center, Dana-Farber Cancer Institute, Boston.

In a widely cited report published in The New England Journal of Medicine in 2016, the International Agency for Research on Cancer (IARC) analyzed over 1000 epidemiologic studies on body fat and cancer. The agency pointed to over a dozen cancers, including some of the most common and deadly, linked to excess body weight.

That list includes esophageal adenocarcinoma and endometrial cancer — associated with the highest risk — along with kidney, liver, stomach (gastric cardia), pancreatic, colorectal, postmenopausal breast, gallbladder, ovarian, and thyroid cancers, plus multiple myeloma and meningioma. There’s also “limited” evidence linking excess weight to additional cancer types, including aggressive prostate cancer and certain head and neck cancers.

At the same time, Dr. Meyerhardt said, many of those same cancers are also associated with issues that lead to, or coexist with, overweight and obesity, including poor diet, lack of exercise, and metabolic conditions such as diabetes. 

It’s a complicated web, and it’s likely, Dr. Meyerhardt said, that high BMI both directly affects cancer risk and is part of a “causal pathway” of other factors that do.

Regarding direct effects, preclinical research has pointed to multiple ways in which excess body fat could contribute to cancer, said Karen M. Basen-Engquist, PhD, MPH, professor, Division of Cancer Prevention and Population Services, The University of Texas MD Anderson Cancer Center, Houston.

One broad mechanism to help explain the obesity-cancer link is chronic systemic inflammation because excess fat tissue can raise levels of substances in the body, such as tumor necrosis factor alpha and interleukin 6, which fuel inflammation. Excess fat also contributes to hyperinsulinemia — too much insulin in the blood — which can help promote the growth and spread of tumor cells. 

But the underlying reasons also appear to vary by cancer type, Dr. Basen-Engquist said. With hormonally driven cancer types, such as breast and endometrial, excess body fat may alter hormone levels in ways that spur tumor growth. Extra fat tissue may, for example, convert androgens into estrogens, which could help feed estrogen-dependent tumors.

That, Dr. Basen-Engquist noted, could be why excess weight is associated with postmenopausal, not premenopausal, breast cancer: Before menopause, body fat is a relatively minor contributor to estrogen levels but becomes more important after menopause.

How Big Is the Effect?

While more than a dozen cancers have been consistently linked to excess weight, the strength of those associations varies considerably. 

Endometrial and esophageal cancers are two that stand out. In the 2016 IARC analysis, people with severe obesity had a seven-times greater risk for endometrial cancer and 4.8-times greater risk for esophageal adenocarcinoma vs people with a normal BMI.

With other cancers, the risk increases for those with severe obesity compared with a normal BMI were far more modest: 10% for ovarian cancer, 30% for colorectal cancer, and 80% for kidney and stomach cancers, for example. For postmenopausal breast cancer, every five-unit increase in BMI was associated with a 10% relative risk increase.

A 2018 study from the American Cancer Society, which attempted to estimate the proportion of cancers in the United States attributable to modifiable risk factors — including alcohol consumption, ultraviolet rays exposure, and physical inactivity — found that smoking accounted for the highest proportion of cancer cases by a wide margin (19%), but excess weight came in second (7.8%).

Again, weight appeared to play a bigger role in certain cancers than others: An estimated 60% of endometrial cancers were linked to excess weight, as were roughly one third of esophageal, kidney, and liver cancers. At the other end of the spectrum, just over 11% of breast, 5% of colorectal, and 4% of ovarian cancers were attributable to excess weight.

Even at the lower end, those rates could make a big difference on the population level, especially for groups with higher rates of obesity.

CDC data show that obesity-related cancers are rising among women younger than 50 years, most rapidly among Hispanic women, and some less common obesity-related cancers, such as stomach, thyroid and pancreatic, are also rising among Black individuals and Hispanic Americans.

Obesity may be one reason for growing cancer disparities, said Leah Ferrucci, PhD, MPH, assistant professor, epidemiology, Yale School of Public Health, New Haven, Connecticut. But, she added, the evidence is limited because Black individuals and Hispanic Americans are understudied.

When Do Extra Pounds Matter?

When it comes to cancer risk, at what point in life does excess weight, or weight gain, matter? Is the standard weight gain in middle age, for instance, as hazardous as being overweight or obese from a young age?

Some evidence suggests there’s no “safe” time for putting on excess pounds.

A recent meta-analysis concluded that weight gain at any point after age 18 years is associated with incremental increases in the risk for postmenopausal breast cancer. A 2023 study in JAMA Network Open found a similar pattern with colorectal and other gastrointestinal cancers: People who had sustained overweight or obesity from age 20 years through middle age faced an increased risk of developing those cancers after age 55 years. 

The timing of weight gain didn’t seem to matter either. The same elevated risk held among people who were normal weight in their younger years but became overweight after age 55 years.

Those studies focused on later-onset disease. But, in recent years, experts have tracked a troubling rise in early-onset cancers — those diagnosed before age 50 years — particularly gastrointestinal cancers. 

An obvious question, Dr. Meyerhardt said, is whether the growing prevalence of obesity among young people is partly to blame.

There’s some data to support that, he said. An analysis from the Nurses’ Health Study II found that women with obesity had double the risk for early-onset colorectal cancer as those with a normal BMI. And every 5-kg increase in weight after age 18 years was associated with a 9% increase in colorectal cancer risk.

But while obesity trends probably partly explain the rise in early-onset cancers, there is likely more to the story, Dr. Meyerhardt said.

“I think all of us who see an increasing number of patients under 50 with colorectal cancer know there’s a fair number who do not fit that [high BMI] profile,” he said. “There’s a fair number over 50 who don’t either.”

Does Weight Loss Help?

With all the evidence pointing to high BMI as a cancer risk factor, a logical conclusion is that weight loss should reduce that excess risk. However, Dr. Bea said, there’s actually little data to support that, and what exists comes from observational studies.

Some research has focused on people who had substantial weight loss after bariatric surgery, with encouraging results. A study published in JAMA found that among 5053 people who underwent bariatric surgery, 2.9% developed an obesity-related cancer over 10 years compared with 4.9% in the nonsurgery group.

Most people, however, aim for less dramatic weight loss, with the help of diet and exercise or sometimes medication. Some evidence shows that a modest degree of weight loss may lower the risks for postmenopausal breast and endometrial cancers. 

A 2020 pooled analysis found, for instance, that among women aged ≥ 50 years, those who lost as little as 2.0-4.5 kg, or 4.4-10.0 pounds, and kept it off for 10 years had a lower risk for breast cancer than women whose weight remained stable. And losing more weight — 9 kg, or about 20 pounds, or more — was even better for lowering cancer risk.

But other research suggests the opposite. A recent analysis found that people who lost weight within the past 2 years through diet and exercise had a higher risk for a range of cancers compared with those who did not lose weight. Overall, though, the increased risk was quite low.

Whatever the research does, or doesn’t, show about weight and cancer risk, Dr. Basen-Engquist said, it’s important that risk factors, obesity and otherwise, aren’t “used as blame tools.”

“With obesity, behavior certainly plays into it,” she said. “But there are so many influences on our behavior that are socially determined.”

Both Dr. Basen-Engquist and Dr. Meyerhardt said it’s important for clinicians to consider the individual in front of them and for everyone to set realistic expectations. 

People with obesity should not feel they have to become thin to be healthier, and no one has to leap from being sedentary to exercising several hours a week. 

“We don’t want patients to feel that if they don’t get to a stated goal in a guideline, it’s all for naught,” Dr. Meyerhardt said.

A version of this article appeared on Medscape.com.

According to the Centers for Disease Control and Prevention (CDC), over 684,000 Americans are diagnosed with an “obesity-associated” cancer each year.

The incidence of many of these cancers has been rising in recent years, particularly among younger people — a trend that sits in contrast with the overall decline in cancers with no established relationship to excess weight, such as lung and skin cancers. 

Is obesity the new smoking? Not exactly.

Tracing a direct line between excess fat and cancer is much less clear-cut than it is with tobacco. While about 42% of cancers — including common ones such as colorectal and postmenopausal breast cancers — are considered obesity-related, only about 8% of incident cancers are attributed to excess body weight. People often develop those diseases regardless of weight.

Although plenty of evidence points to excess body fat as a cancer risk factor, it’s unclear at what point excess weight has an effect. Is gaining weight later in life, for instance, better or worse for cancer risk than being overweight or obese from a young age?

There’s another glaring knowledge gap: Does losing weight at some point in adulthood change the picture? In other words, how many of those 684,000 diagnoses might have been prevented if people shed excess pounds?

When it comes to weight and cancer risk, “there’s a lot we don’t know,” said Jennifer W. Bea, PhD, associate professor, health promotion sciences, University of Arizona, Tucson.

A Consistent but Complicated Relationship

Given the growing incidence of obesity — which currently affects about 42% of US adults and 20% of children and teenagers — it’s no surprise that many studies have delved into the potential effects of excess weight on cancer rates.

Although virtually all the evidence comes from large cohort studies, leaving the cause-effect question open, certain associations keep showing up.

“What we know is that, consistently, a higher body mass index [BMI] — particularly in the obese category — leads to a higher risk of multiple cancers,” said Jeffrey A. Meyerhardt, MD, MPH, codirector, Colon and Rectal Cancer Center, Dana-Farber Cancer Institute, Boston.

In a widely cited report published in The New England Journal of Medicine in 2016, the International Agency for Research on Cancer (IARC) analyzed over 1000 epidemiologic studies on body fat and cancer. The agency pointed to over a dozen cancers, including some of the most common and deadly, linked to excess body weight.

That list includes esophageal adenocarcinoma and endometrial cancer — associated with the highest risk — along with kidney, liver, stomach (gastric cardia), pancreatic, colorectal, postmenopausal breast, gallbladder, ovarian, and thyroid cancers, plus multiple myeloma and meningioma. There’s also “limited” evidence linking excess weight to additional cancer types, including aggressive prostate cancer and certain head and neck cancers.

At the same time, Dr. Meyerhardt said, many of those same cancers are also associated with issues that lead to, or coexist with, overweight and obesity, including poor diet, lack of exercise, and metabolic conditions such as diabetes. 

It’s a complicated web, and it’s likely, Dr. Meyerhardt said, that high BMI both directly affects cancer risk and is part of a “causal pathway” of other factors that do.

Regarding direct effects, preclinical research has pointed to multiple ways in which excess body fat could contribute to cancer, said Karen M. Basen-Engquist, PhD, MPH, professor, Division of Cancer Prevention and Population Services, The University of Texas MD Anderson Cancer Center, Houston.

One broad mechanism to help explain the obesity-cancer link is chronic systemic inflammation because excess fat tissue can raise levels of substances in the body, such as tumor necrosis factor alpha and interleukin 6, which fuel inflammation. Excess fat also contributes to hyperinsulinemia — too much insulin in the blood — which can help promote the growth and spread of tumor cells. 

But the underlying reasons also appear to vary by cancer type, Dr. Basen-Engquist said. With hormonally driven cancer types, such as breast and endometrial, excess body fat may alter hormone levels in ways that spur tumor growth. Extra fat tissue may, for example, convert androgens into estrogens, which could help feed estrogen-dependent tumors.

That, Dr. Basen-Engquist noted, could be why excess weight is associated with postmenopausal, not premenopausal, breast cancer: Before menopause, body fat is a relatively minor contributor to estrogen levels but becomes more important after menopause.

How Big Is the Effect?

While more than a dozen cancers have been consistently linked to excess weight, the strength of those associations varies considerably. 

Endometrial and esophageal cancers are two that stand out. In the 2016 IARC analysis, people with severe obesity had a seven-times greater risk for endometrial cancer and 4.8-times greater risk for esophageal adenocarcinoma vs people with a normal BMI.

With other cancers, the risk increases for those with severe obesity compared with a normal BMI were far more modest: 10% for ovarian cancer, 30% for colorectal cancer, and 80% for kidney and stomach cancers, for example. For postmenopausal breast cancer, every five-unit increase in BMI was associated with a 10% relative risk increase.

A 2018 study from the American Cancer Society, which attempted to estimate the proportion of cancers in the United States attributable to modifiable risk factors — including alcohol consumption, ultraviolet rays exposure, and physical inactivity — found that smoking accounted for the highest proportion of cancer cases by a wide margin (19%), but excess weight came in second (7.8%).

Again, weight appeared to play a bigger role in certain cancers than others: An estimated 60% of endometrial cancers were linked to excess weight, as were roughly one third of esophageal, kidney, and liver cancers. At the other end of the spectrum, just over 11% of breast, 5% of colorectal, and 4% of ovarian cancers were attributable to excess weight.

Even at the lower end, those rates could make a big difference on the population level, especially for groups with higher rates of obesity.

CDC data show that obesity-related cancers are rising among women younger than 50 years, most rapidly among Hispanic women, and some less common obesity-related cancers, such as stomach, thyroid and pancreatic, are also rising among Black individuals and Hispanic Americans.

Obesity may be one reason for growing cancer disparities, said Leah Ferrucci, PhD, MPH, assistant professor, epidemiology, Yale School of Public Health, New Haven, Connecticut. But, she added, the evidence is limited because Black individuals and Hispanic Americans are understudied.

When Do Extra Pounds Matter?

When it comes to cancer risk, at what point in life does excess weight, or weight gain, matter? Is the standard weight gain in middle age, for instance, as hazardous as being overweight or obese from a young age?

Some evidence suggests there’s no “safe” time for putting on excess pounds.

A recent meta-analysis concluded that weight gain at any point after age 18 years is associated with incremental increases in the risk for postmenopausal breast cancer. A 2023 study in JAMA Network Open found a similar pattern with colorectal and other gastrointestinal cancers: People who had sustained overweight or obesity from age 20 years through middle age faced an increased risk of developing those cancers after age 55 years. 

The timing of weight gain didn’t seem to matter either. The same elevated risk held among people who were normal weight in their younger years but became overweight after age 55 years.

Those studies focused on later-onset disease. But, in recent years, experts have tracked a troubling rise in early-onset cancers — those diagnosed before age 50 years — particularly gastrointestinal cancers. 

An obvious question, Dr. Meyerhardt said, is whether the growing prevalence of obesity among young people is partly to blame.

There’s some data to support that, he said. An analysis from the Nurses’ Health Study II found that women with obesity had double the risk for early-onset colorectal cancer as those with a normal BMI. And every 5-kg increase in weight after age 18 years was associated with a 9% increase in colorectal cancer risk.

But while obesity trends probably partly explain the rise in early-onset cancers, there is likely more to the story, Dr. Meyerhardt said.

“I think all of us who see an increasing number of patients under 50 with colorectal cancer know there’s a fair number who do not fit that [high BMI] profile,” he said. “There’s a fair number over 50 who don’t either.”

Does Weight Loss Help?

With all the evidence pointing to high BMI as a cancer risk factor, a logical conclusion is that weight loss should reduce that excess risk. However, Dr. Bea said, there’s actually little data to support that, and what exists comes from observational studies.

Some research has focused on people who had substantial weight loss after bariatric surgery, with encouraging results. A study published in JAMA found that among 5053 people who underwent bariatric surgery, 2.9% developed an obesity-related cancer over 10 years compared with 4.9% in the nonsurgery group.

Most people, however, aim for less dramatic weight loss, with the help of diet and exercise or sometimes medication. Some evidence shows that a modest degree of weight loss may lower the risks for postmenopausal breast and endometrial cancers. 

A 2020 pooled analysis found, for instance, that among women aged ≥ 50 years, those who lost as little as 2.0-4.5 kg, or 4.4-10.0 pounds, and kept it off for 10 years had a lower risk for breast cancer than women whose weight remained stable. And losing more weight — 9 kg, or about 20 pounds, or more — was even better for lowering cancer risk.

But other research suggests the opposite. A recent analysis found that people who lost weight within the past 2 years through diet and exercise had a higher risk for a range of cancers compared with those who did not lose weight. Overall, though, the increased risk was quite low.

Whatever the research does, or doesn’t, show about weight and cancer risk, Dr. Basen-Engquist said, it’s important that risk factors, obesity and otherwise, aren’t “used as blame tools.”

“With obesity, behavior certainly plays into it,” she said. “But there are so many influences on our behavior that are socially determined.”

Both Dr. Basen-Engquist and Dr. Meyerhardt said it’s important for clinicians to consider the individual in front of them and for everyone to set realistic expectations. 

People with obesity should not feel they have to become thin to be healthier, and no one has to leap from being sedentary to exercising several hours a week. 

“We don’t want patients to feel that if they don’t get to a stated goal in a guideline, it’s all for naught,” Dr. Meyerhardt said.

A version of this article appeared on Medscape.com.

Patients with metastatic or advanced cancer treated in practices that have high rates of giving systemic care in the last two weeks of life do not have longer survival rates than patients in practices that have low rates of such care.

This conclusion of a new study published online May 16 in JAMA Oncology may help reassure oncologists that giving systemic anticancer therapy (SACT) at the most advanced stages of cancer will not improve the patient’s life, the authors wrote. It also may encourage them to instead focus more on honest communication with patients about their choices, Maureen E. Canavan, PhD, at the Cancer and Outcomes, Public Policy and Effectiveness Research (COPPER) Center at the Yale School of Medicine in New Haven, Connecticut, and colleagues, wrote in their paper.
 

How Was the Study Conducted?

Researchers used Flatiron Health, a nationwide electronic health records database of academic and community practices throughout the United State. They identified 78,446 adults with advanced or metastatic stages of one of six common cancers (breast, colorectal, urothelial, non–small cell lung cancer [NSCLC], pancreatic and renal cell carcinoma) who were treated at healthcare practices from 2015 to 2019. They then stratified practices into quintiles based on how often the practices treated patients with any systemic therapy, including chemotherapy and immunotherapy, in their last 14 days of life. They compared whether patients in practices with greater use of systemic treatment at very advanced stages had longer overall survival.

What Were the Main Findings?

“We saw that there were absolutely no survival differences between the practices that used more systemic therapy for very advanced cancer than the practices that use less,” said senior author Kerin Adelson, MD, chief quality and value officer at MD Anderson Cancer Center in Houston, Texas. In some cancers, those in the lowest quintile (those with the lowest rates of systemic end-of-life care) lived fewer years compared with those in the highest quintiles. In other cancers, those in the lowest quintiles lived more years than those in the highest quintiles.

“What’s important is that none of those differences, after you control for other factors, was statistically significant,” Dr. Adelson said. “That was the same in every cancer type we looked at.”

An example is seen in advanced urothelial cancer. Those in the first quintile (lowest rates of systemic care at end of life) had an SACT rate range of 4.0-9.1. The SACT rate range in the highest quintile was 19.8-42.6. But the median overall survival (OS) rate for those in the lowest quintile was 12.7 months, not statistically different from the median OS in the highest quintile (11 months.)
 

How Does This Study Add to the Literature?

The American Society of Clinical Oncology (ASCO) and the National Quality Forum (NQF) developed a cancer quality metric to reduce SACT at the end of life. The NQF 0210 is a ratio of patients who get systemic treatment within 14 days of death over all patients who die of cancer. The quality metric has been widely adopted and used in value-based care reporting.

But the metric has been criticized because it focuses only on people who died and not people who lived longer because they benefited from the systemic therapy, the authors wrote.

Dr. Canavan’s team focused on all patients treated in the practice, not just those who died, Dr. Adelson said. This may put that criticism to rest, Dr. Adelson said.

“I personally believed the ASCO and NQF metric was appropriate and the criticisms were off base,” said Otis Brawley, MD, associate director of community outreach and engagement at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University School of Medicine in Baltimore. “Canavan’s study is evidence suggesting the metrics were appropriate.”

This study included not just chemotherapy, as some other studies have, but targeted therapies and immunotherapies as well. Dr. Adelson said some think that the newer drugs might change the prognosis at end of life. But this study shows “even those drugs are not helping patients to survive with very advanced cancer,” she said.

 

Could This Change Practice?

The authors noted that end-of life SACT has been linked with more acute care use, delays in conversations about care goals, late enrollment in hospice, higher costs, and potentially shorter and poorer quality life.

Dr. Adelson said she’s hoping that the knowledge that there’s no survival benefit for use of SACT for patients with advanced solid tumors who are nearing the end of life will lead instead to more conversations about prognosis with patients and transitions to palliative care.

“Palliative care has actually been shown to improve quality of life and, in some studies, even survival,” she said.

“I doubt it will change practice, but it should,” Dr. Brawley said. “The study suggests that doctors and patients have too much hope for chemotherapy as patients’ disease progresses. In the US especially, there is a tendency to believe we have better therapies than we truly do and we have difficulty accepting that the patient is dying. Many patients get third- and fourth-line chemotherapy that is highly likely to increase suffering without realistic hope of prolonging life and especially no hope of prolonging life with good quality.”

Dr. Adelson disclosed ties with AbbVie, Quantum Health, Gilead, ParetoHealth, and Carrum Health. Various coauthors disclosed ties with Roche, AbbVie, Johnson & Johnson, Genentech, the National Comprehensive Cancer Network, and AstraZeneca. The study was funded by Flatiron Health, an independent member of the Roche group. Dr. Brawley reports no relevant financial disclosures.

Patients with metastatic or advanced cancer treated in practices that have high rates of giving systemic care in the last two weeks of life do not have longer survival rates than patients in practices that have low rates of such care.

This conclusion of a new study published online May 16 in JAMA Oncology may help reassure oncologists that giving systemic anticancer therapy (SACT) at the most advanced stages of cancer will not improve the patient’s life, the authors wrote. It also may encourage them to instead focus more on honest communication with patients about their choices, Maureen E. Canavan, PhD, at the Cancer and Outcomes, Public Policy and Effectiveness Research (COPPER) Center at the Yale School of Medicine in New Haven, Connecticut, and colleagues, wrote in their paper.
 

How Was the Study Conducted?

Researchers used Flatiron Health, a nationwide electronic health records database of academic and community practices throughout the United State. They identified 78,446 adults with advanced or metastatic stages of one of six common cancers (breast, colorectal, urothelial, non–small cell lung cancer [NSCLC], pancreatic and renal cell carcinoma) who were treated at healthcare practices from 2015 to 2019. They then stratified practices into quintiles based on how often the practices treated patients with any systemic therapy, including chemotherapy and immunotherapy, in their last 14 days of life. They compared whether patients in practices with greater use of systemic treatment at very advanced stages had longer overall survival.

What Were the Main Findings?

“We saw that there were absolutely no survival differences between the practices that used more systemic therapy for very advanced cancer than the practices that use less,” said senior author Kerin Adelson, MD, chief quality and value officer at MD Anderson Cancer Center in Houston, Texas. In some cancers, those in the lowest quintile (those with the lowest rates of systemic end-of-life care) lived fewer years compared with those in the highest quintiles. In other cancers, those in the lowest quintiles lived more years than those in the highest quintiles.

“What’s important is that none of those differences, after you control for other factors, was statistically significant,” Dr. Adelson said. “That was the same in every cancer type we looked at.”

An example is seen in advanced urothelial cancer. Those in the first quintile (lowest rates of systemic care at end of life) had an SACT rate range of 4.0-9.1. The SACT rate range in the highest quintile was 19.8-42.6. But the median overall survival (OS) rate for those in the lowest quintile was 12.7 months, not statistically different from the median OS in the highest quintile (11 months.)
 

How Does This Study Add to the Literature?

The American Society of Clinical Oncology (ASCO) and the National Quality Forum (NQF) developed a cancer quality metric to reduce SACT at the end of life. The NQF 0210 is a ratio of patients who get systemic treatment within 14 days of death over all patients who die of cancer. The quality metric has been widely adopted and used in value-based care reporting.

But the metric has been criticized because it focuses only on people who died and not people who lived longer because they benefited from the systemic therapy, the authors wrote.

Dr. Canavan’s team focused on all patients treated in the practice, not just those who died, Dr. Adelson said. This may put that criticism to rest, Dr. Adelson said.

“I personally believed the ASCO and NQF metric was appropriate and the criticisms were off base,” said Otis Brawley, MD, associate director of community outreach and engagement at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University School of Medicine in Baltimore. “Canavan’s study is evidence suggesting the metrics were appropriate.”

This study included not just chemotherapy, as some other studies have, but targeted therapies and immunotherapies as well. Dr. Adelson said some think that the newer drugs might change the prognosis at end of life. But this study shows “even those drugs are not helping patients to survive with very advanced cancer,” she said.

 

Could This Change Practice?

The authors noted that end-of life SACT has been linked with more acute care use, delays in conversations about care goals, late enrollment in hospice, higher costs, and potentially shorter and poorer quality life.

Dr. Adelson said she’s hoping that the knowledge that there’s no survival benefit for use of SACT for patients with advanced solid tumors who are nearing the end of life will lead instead to more conversations about prognosis with patients and transitions to palliative care.

“Palliative care has actually been shown to improve quality of life and, in some studies, even survival,” she said.

“I doubt it will change practice, but it should,” Dr. Brawley said. “The study suggests that doctors and patients have too much hope for chemotherapy as patients’ disease progresses. In the US especially, there is a tendency to believe we have better therapies than we truly do and we have difficulty accepting that the patient is dying. Many patients get third- and fourth-line chemotherapy that is highly likely to increase suffering without realistic hope of prolonging life and especially no hope of prolonging life with good quality.”

Dr. Adelson disclosed ties with AbbVie, Quantum Health, Gilead, ParetoHealth, and Carrum Health. Various coauthors disclosed ties with Roche, AbbVie, Johnson & Johnson, Genentech, the National Comprehensive Cancer Network, and AstraZeneca. The study was funded by Flatiron Health, an independent member of the Roche group. Dr. Brawley reports no relevant financial disclosures.

Patients with metastatic or advanced cancer treated in practices that have high rates of giving systemic care in the last two weeks of life do not have longer survival rates than patients in practices that have low rates of such care.

This conclusion of a new study published online May 16 in JAMA Oncology may help reassure oncologists that giving systemic anticancer therapy (SACT) at the most advanced stages of cancer will not improve the patient’s life, the authors wrote. It also may encourage them to instead focus more on honest communication with patients about their choices, Maureen E. Canavan, PhD, at the Cancer and Outcomes, Public Policy and Effectiveness Research (COPPER) Center at the Yale School of Medicine in New Haven, Connecticut, and colleagues, wrote in their paper.
 

How Was the Study Conducted?

Researchers used Flatiron Health, a nationwide electronic health records database of academic and community practices throughout the United State. They identified 78,446 adults with advanced or metastatic stages of one of six common cancers (breast, colorectal, urothelial, non–small cell lung cancer [NSCLC], pancreatic and renal cell carcinoma) who were treated at healthcare practices from 2015 to 2019. They then stratified practices into quintiles based on how often the practices treated patients with any systemic therapy, including chemotherapy and immunotherapy, in their last 14 days of life. They compared whether patients in practices with greater use of systemic treatment at very advanced stages had longer overall survival.

What Were the Main Findings?

“We saw that there were absolutely no survival differences between the practices that used more systemic therapy for very advanced cancer than the practices that use less,” said senior author Kerin Adelson, MD, chief quality and value officer at MD Anderson Cancer Center in Houston, Texas. In some cancers, those in the lowest quintile (those with the lowest rates of systemic end-of-life care) lived fewer years compared with those in the highest quintiles. In other cancers, those in the lowest quintiles lived more years than those in the highest quintiles.

“What’s important is that none of those differences, after you control for other factors, was statistically significant,” Dr. Adelson said. “That was the same in every cancer type we looked at.”

An example is seen in advanced urothelial cancer. Those in the first quintile (lowest rates of systemic care at end of life) had an SACT rate range of 4.0-9.1. The SACT rate range in the highest quintile was 19.8-42.6. But the median overall survival (OS) rate for those in the lowest quintile was 12.7 months, not statistically different from the median OS in the highest quintile (11 months.)
 

How Does This Study Add to the Literature?

The American Society of Clinical Oncology (ASCO) and the National Quality Forum (NQF) developed a cancer quality metric to reduce SACT at the end of life. The NQF 0210 is a ratio of patients who get systemic treatment within 14 days of death over all patients who die of cancer. The quality metric has been widely adopted and used in value-based care reporting.

But the metric has been criticized because it focuses only on people who died and not people who lived longer because they benefited from the systemic therapy, the authors wrote.

Dr. Canavan’s team focused on all patients treated in the practice, not just those who died, Dr. Adelson said. This may put that criticism to rest, Dr. Adelson said.

“I personally believed the ASCO and NQF metric was appropriate and the criticisms were off base,” said Otis Brawley, MD, associate director of community outreach and engagement at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University School of Medicine in Baltimore. “Canavan’s study is evidence suggesting the metrics were appropriate.”

This study included not just chemotherapy, as some other studies have, but targeted therapies and immunotherapies as well. Dr. Adelson said some think that the newer drugs might change the prognosis at end of life. But this study shows “even those drugs are not helping patients to survive with very advanced cancer,” she said.

 

Could This Change Practice?

The authors noted that end-of life SACT has been linked with more acute care use, delays in conversations about care goals, late enrollment in hospice, higher costs, and potentially shorter and poorer quality life.

Dr. Adelson said she’s hoping that the knowledge that there’s no survival benefit for use of SACT for patients with advanced solid tumors who are nearing the end of life will lead instead to more conversations about prognosis with patients and transitions to palliative care.

“Palliative care has actually been shown to improve quality of life and, in some studies, even survival,” she said.

“I doubt it will change practice, but it should,” Dr. Brawley said. “The study suggests that doctors and patients have too much hope for chemotherapy as patients’ disease progresses. In the US especially, there is a tendency to believe we have better therapies than we truly do and we have difficulty accepting that the patient is dying. Many patients get third- and fourth-line chemotherapy that is highly likely to increase suffering without realistic hope of prolonging life and especially no hope of prolonging life with good quality.”

Dr. Adelson disclosed ties with AbbVie, Quantum Health, Gilead, ParetoHealth, and Carrum Health. Various coauthors disclosed ties with Roche, AbbVie, Johnson & Johnson, Genentech, the National Comprehensive Cancer Network, and AstraZeneca. The study was funded by Flatiron Health, an independent member of the Roche group. Dr. Brawley reports no relevant financial disclosures.

The next frontier in cancer detection could be the humble urine test.

Emerging science suggests that the body’s “liquid gold” could be particularly useful for liquid biopsies, offering a convenient, pain-free, and cost-effective way to spot otherwise hard-to-detect cancers.

“The search for cancer biomarkers that can be detected in urine could provide an enormous step forward to decrease cancer patient mortality,” said Kenneth R. Shroyer, MD, PhD, a pathologist at Stony Brook University, Stony Brook, New York, who studies cancer biomarkers.

Physicians have long known that urine can reveal a lot about our health — that’s why urinalysis has been part of medicine for 6000 years. Urine tests can detect diabetes, pregnancy, drug use, and urinary or kidney conditions.

But other conditions leave clues in urine, too, and cancer may be one of the most promising. “Urine testing could detect biomarkers of early-stage cancers, not only from local but also distant sites,” Dr. Shroyer said. It could also help flag recurrence in cancer survivors who have undergone treatment.

Granted, cancer biomarkers in urine are not nearly as widely studied as those in the blood, Dr. Shroyer noted. But a new wave of urine tests suggests research is gaining pace.

“The recent availability of high-throughput screening technologies has enabled researchers to investigate cancer from a top-down, comprehensive approach,” said Pak Kin Wong, PhD, professor of mechanical engineering, biomedical engineering, and surgery at The Pennsylvania State University. “We are starting to understand the rich information that can be obtained from urine.”

Urine is mostly water (about 95%) and urea, a metabolic byproduct that imparts that signature yellow color (about 2%). The other 3% is a mix of waste products, minerals, and other compounds the kidneys removed from the blood. Even in trace amounts, these substances say a lot.

Among them are “exfoliated cancer cells, cell-free DNA, hormones, and the urine microbiota — the collection of microbes in our urinary tract system,” Dr. Wong said.

“It is highly promising to be one of the major biological fluids used for screening, diagnosis, prognosis, and monitoring treatment efficiency in the era of precision medicine,” Dr. Wong said.

How Urine Testing Could Reveal Cancer

Still, as exciting as the prospect is, there’s a lot to consider in the hunt for cancer biomarkers in urine. These biomarkers must be able to pass through the renal nephrons (filtering units), remain stable in urine, and have high-level sensitivity, Dr. Shroyer said. They should also have high specificity for cancer vs benign conditions and be expressed at early stages, before the primary tumor has spread.

“At this stage, few circulating biomarkers have been found that are both sensitive and specific for early-stage disease,” said Dr. Shroyer.

But there are a few promising examples under investigation in humans:

Prostate cancer. Researchers at the University of Michigan have developed a urine test that detects high-grade prostate cancer more accurately than existing tests, including PHI, SelectMDx, 4Kscore, EPI, MPS, and IsoPSA.

The MyProstateScore 2.0 (MPS2) test, which looks for 18 genes associated with high-grade tumors, could reduce unnecessary biopsies in men with elevated prostate-specific antigen levels, according to a paper published in JAMA Oncology.

It makes sense. The prostate gland secretes fluid that becomes part of the semen, traces of which enter urine. After a digital rectal exam, even more prostate fluid enters the urine. If a patient has prostate cancer, genetic material from the cancer cells will infiltrate the urine.

In the MPS2 test, researchers used polymerase chain reaction (PCR) testing in urine. “The technology used for COVID PCR is essentially the same as the PCR used to detect transcripts associated with high-grade prostate cancer in urine,” said study author Arul Chinnaiyan, MD, PhD, director of the Michigan Center for Translational Pathology at the University of Michigan, Ann Arbor. “In the case of the MPS2 test, we are doing PCR on 18 genes simultaneously on urine samples.”

A statistical model uses levels of that genetic material to predict the risk for high-grade disease, helping doctors decide what to do next. At 95% sensitivity, the MPS2 model could eliminate 35%-45% of unnecessary biopsies, compared with 15%-30% for the other tests, and reduce repeat biopsies by 46%-51%, compared with 9%-21% for the other tests.

Head and neck cancer. In a paper published in JCI Insight, researchers described a test that finds ultra-short fragments of DNA in urine to enable early detection of head and neck cancers caused by human papillomavirus.

“Our data show that a relatively small volume of urine (30-60 mL) gives overall detection results comparable to a tube of blood,” said study author Muneesh Tewari, MD, PhD, professor of hematology and oncology at the University of Michigan .

A larger volume of urine could potentially “make cancer detection even more sensitive than blood,” Dr. Tewari said, “allowing cancers to be detected at the earliest stages when they are more curable.”

The team used a technique called droplet digital PCR to detect DNA fragments that are “ultra-short” (less than 50 base pairs long) and usually missed by conventional PCR testing. This transrenal cell-free tumor DNA, which travels from the tumor into the bloodstream, is broken down small enough to pass through the kidneys and into the urine. But the fragments are still long enough to carry information about the tumor’s genetic signature.

This test could spot cancer before a tumor grows big enough — about a centimeter wide and carrying a billion cells — to spot on a CT scan or other imaging test. “When we are instead detecting fragments of DNA released from a tumor,” said Dr. Tewari, “our testing methods are very sensitive and can detect DNA in urine that came from just 5-10 cells in a tumor that died and released their DNA into the blood, which then made its way into the urine.”

Pancreatic cancer. Pancreatic ductal adenocarcinoma is one of the deadliest cancers, largely because it is diagnosed so late. A urine panel now in clinical trials could help doctors diagnose the cancer before it has spread so more people can have the tumor surgically removed, improving prognosis.

Using enzyme-linked immunosorbent assay test, a common lab method that detects antibodies and other proteins, the team measured expression levels for three genes (LYVE1, REG1B, and TFF1) in urine samples collected from people up to 5 years before they were diagnosed with pancreatic cancer. The researchers combined this result with patients’ urinary creatinine levels, a common component of existing urinalysis, and their age to develop a risk score.

This score performed similarly to an existing blood test, CA19-9, in predicting patients’ risk for pancreatic cancer up to 1 year before diagnosis. When combined with CA19-9, the urinary panel helped spot cancer up to 2 years before diagnosis.

According to a paper in the International Journal of Cancer, “the urine panel and affiliated PancRISK are currently being validated in a prospective clinical study (UroPanc).” If all goes well, they could be implemented in clinical practice in a few years as a “noninvasive stratification tool” to identify patients for further testing, speeding up diagnosis, and saving lives.

Limitations and Promises

Each cancer type is different, and more research is needed to map out which substances in urine predict which cancers and to develop tests for mass adoption. “There are medical and technological hurdles to the large-scale implementation of urine analysis for complex diseases such as cancer,” said Dr. Wong.

One possibility: Scientists and clinicians could collaborate and use artificial intelligence techniques to combine urine test results with other data.

“It is likely that future diagnostics may combine urine with other biological samples such as feces and saliva, among others,” said Dr. Wong. “This is especially true when novel data science and machine learning techniques can integrate comprehensive data from patients that span genetic, proteomic, metabolic, microbiomic, and even behavioral data to evaluate a patient’s condition.”

One thing that excites Dr. Tewari about urine-based cancer testing: “We think it could be especially impactful for patients living in rural areas or other areas with less access to healthcare services,” he said.
 

A version of this article appeared on Medscape.com.

The next frontier in cancer detection could be the humble urine test.

Emerging science suggests that the body’s “liquid gold” could be particularly useful for liquid biopsies, offering a convenient, pain-free, and cost-effective way to spot otherwise hard-to-detect cancers.

“The search for cancer biomarkers that can be detected in urine could provide an enormous step forward to decrease cancer patient mortality,” said Kenneth R. Shroyer, MD, PhD, a pathologist at Stony Brook University, Stony Brook, New York, who studies cancer biomarkers.

Physicians have long known that urine can reveal a lot about our health — that’s why urinalysis has been part of medicine for 6000 years. Urine tests can detect diabetes, pregnancy, drug use, and urinary or kidney conditions.

But other conditions leave clues in urine, too, and cancer may be one of the most promising. “Urine testing could detect biomarkers of early-stage cancers, not only from local but also distant sites,” Dr. Shroyer said. It could also help flag recurrence in cancer survivors who have undergone treatment.

Granted, cancer biomarkers in urine are not nearly as widely studied as those in the blood, Dr. Shroyer noted. But a new wave of urine tests suggests research is gaining pace.

“The recent availability of high-throughput screening technologies has enabled researchers to investigate cancer from a top-down, comprehensive approach,” said Pak Kin Wong, PhD, professor of mechanical engineering, biomedical engineering, and surgery at The Pennsylvania State University. “We are starting to understand the rich information that can be obtained from urine.”

Urine is mostly water (about 95%) and urea, a metabolic byproduct that imparts that signature yellow color (about 2%). The other 3% is a mix of waste products, minerals, and other compounds the kidneys removed from the blood. Even in trace amounts, these substances say a lot.

Among them are “exfoliated cancer cells, cell-free DNA, hormones, and the urine microbiota — the collection of microbes in our urinary tract system,” Dr. Wong said.

“It is highly promising to be one of the major biological fluids used for screening, diagnosis, prognosis, and monitoring treatment efficiency in the era of precision medicine,” Dr. Wong said.

How Urine Testing Could Reveal Cancer

Still, as exciting as the prospect is, there’s a lot to consider in the hunt for cancer biomarkers in urine. These biomarkers must be able to pass through the renal nephrons (filtering units), remain stable in urine, and have high-level sensitivity, Dr. Shroyer said. They should also have high specificity for cancer vs benign conditions and be expressed at early stages, before the primary tumor has spread.

“At this stage, few circulating biomarkers have been found that are both sensitive and specific for early-stage disease,” said Dr. Shroyer.

But there are a few promising examples under investigation in humans:

Prostate cancer. Researchers at the University of Michigan have developed a urine test that detects high-grade prostate cancer more accurately than existing tests, including PHI, SelectMDx, 4Kscore, EPI, MPS, and IsoPSA.

The MyProstateScore 2.0 (MPS2) test, which looks for 18 genes associated with high-grade tumors, could reduce unnecessary biopsies in men with elevated prostate-specific antigen levels, according to a paper published in JAMA Oncology.

It makes sense. The prostate gland secretes fluid that becomes part of the semen, traces of which enter urine. After a digital rectal exam, even more prostate fluid enters the urine. If a patient has prostate cancer, genetic material from the cancer cells will infiltrate the urine.

In the MPS2 test, researchers used polymerase chain reaction (PCR) testing in urine. “The technology used for COVID PCR is essentially the same as the PCR used to detect transcripts associated with high-grade prostate cancer in urine,” said study author Arul Chinnaiyan, MD, PhD, director of the Michigan Center for Translational Pathology at the University of Michigan, Ann Arbor. “In the case of the MPS2 test, we are doing PCR on 18 genes simultaneously on urine samples.”

A statistical model uses levels of that genetic material to predict the risk for high-grade disease, helping doctors decide what to do next. At 95% sensitivity, the MPS2 model could eliminate 35%-45% of unnecessary biopsies, compared with 15%-30% for the other tests, and reduce repeat biopsies by 46%-51%, compared with 9%-21% for the other tests.

Head and neck cancer. In a paper published in JCI Insight, researchers described a test that finds ultra-short fragments of DNA in urine to enable early detection of head and neck cancers caused by human papillomavirus.

“Our data show that a relatively small volume of urine (30-60 mL) gives overall detection results comparable to a tube of blood,” said study author Muneesh Tewari, MD, PhD, professor of hematology and oncology at the University of Michigan .

A larger volume of urine could potentially “make cancer detection even more sensitive than blood,” Dr. Tewari said, “allowing cancers to be detected at the earliest stages when they are more curable.”

The team used a technique called droplet digital PCR to detect DNA fragments that are “ultra-short” (less than 50 base pairs long) and usually missed by conventional PCR testing. This transrenal cell-free tumor DNA, which travels from the tumor into the bloodstream, is broken down small enough to pass through the kidneys and into the urine. But the fragments are still long enough to carry information about the tumor’s genetic signature.

This test could spot cancer before a tumor grows big enough — about a centimeter wide and carrying a billion cells — to spot on a CT scan or other imaging test. “When we are instead detecting fragments of DNA released from a tumor,” said Dr. Tewari, “our testing methods are very sensitive and can detect DNA in urine that came from just 5-10 cells in a tumor that died and released their DNA into the blood, which then made its way into the urine.”

Pancreatic cancer. Pancreatic ductal adenocarcinoma is one of the deadliest cancers, largely because it is diagnosed so late. A urine panel now in clinical trials could help doctors diagnose the cancer before it has spread so more people can have the tumor surgically removed, improving prognosis.

Using enzyme-linked immunosorbent assay test, a common lab method that detects antibodies and other proteins, the team measured expression levels for three genes (LYVE1, REG1B, and TFF1) in urine samples collected from people up to 5 years before they were diagnosed with pancreatic cancer. The researchers combined this result with patients’ urinary creatinine levels, a common component of existing urinalysis, and their age to develop a risk score.

This score performed similarly to an existing blood test, CA19-9, in predicting patients’ risk for pancreatic cancer up to 1 year before diagnosis. When combined with CA19-9, the urinary panel helped spot cancer up to 2 years before diagnosis.

According to a paper in the International Journal of Cancer, “the urine panel and affiliated PancRISK are currently being validated in a prospective clinical study (UroPanc).” If all goes well, they could be implemented in clinical practice in a few years as a “noninvasive stratification tool” to identify patients for further testing, speeding up diagnosis, and saving lives.

Limitations and Promises

Each cancer type is different, and more research is needed to map out which substances in urine predict which cancers and to develop tests for mass adoption. “There are medical and technological hurdles to the large-scale implementation of urine analysis for complex diseases such as cancer,” said Dr. Wong.

One possibility: Scientists and clinicians could collaborate and use artificial intelligence techniques to combine urine test results with other data.

“It is likely that future diagnostics may combine urine with other biological samples such as feces and saliva, among others,” said Dr. Wong. “This is especially true when novel data science and machine learning techniques can integrate comprehensive data from patients that span genetic, proteomic, metabolic, microbiomic, and even behavioral data to evaluate a patient’s condition.”

One thing that excites Dr. Tewari about urine-based cancer testing: “We think it could be especially impactful for patients living in rural areas or other areas with less access to healthcare services,” he said.
 

A version of this article appeared on Medscape.com.

The next frontier in cancer detection could be the humble urine test.

Emerging science suggests that the body’s “liquid gold” could be particularly useful for liquid biopsies, offering a convenient, pain-free, and cost-effective way to spot otherwise hard-to-detect cancers.

“The search for cancer biomarkers that can be detected in urine could provide an enormous step forward to decrease cancer patient mortality,” said Kenneth R. Shroyer, MD, PhD, a pathologist at Stony Brook University, Stony Brook, New York, who studies cancer biomarkers.

Physicians have long known that urine can reveal a lot about our health — that’s why urinalysis has been part of medicine for 6000 years. Urine tests can detect diabetes, pregnancy, drug use, and urinary or kidney conditions.

But other conditions leave clues in urine, too, and cancer may be one of the most promising. “Urine testing could detect biomarkers of early-stage cancers, not only from local but also distant sites,” Dr. Shroyer said. It could also help flag recurrence in cancer survivors who have undergone treatment.

Granted, cancer biomarkers in urine are not nearly as widely studied as those in the blood, Dr. Shroyer noted. But a new wave of urine tests suggests research is gaining pace.

“The recent availability of high-throughput screening technologies has enabled researchers to investigate cancer from a top-down, comprehensive approach,” said Pak Kin Wong, PhD, professor of mechanical engineering, biomedical engineering, and surgery at The Pennsylvania State University. “We are starting to understand the rich information that can be obtained from urine.”

Urine is mostly water (about 95%) and urea, a metabolic byproduct that imparts that signature yellow color (about 2%). The other 3% is a mix of waste products, minerals, and other compounds the kidneys removed from the blood. Even in trace amounts, these substances say a lot.

Among them are “exfoliated cancer cells, cell-free DNA, hormones, and the urine microbiota — the collection of microbes in our urinary tract system,” Dr. Wong said.

“It is highly promising to be one of the major biological fluids used for screening, diagnosis, prognosis, and monitoring treatment efficiency in the era of precision medicine,” Dr. Wong said.

How Urine Testing Could Reveal Cancer

Still, as exciting as the prospect is, there’s a lot to consider in the hunt for cancer biomarkers in urine. These biomarkers must be able to pass through the renal nephrons (filtering units), remain stable in urine, and have high-level sensitivity, Dr. Shroyer said. They should also have high specificity for cancer vs benign conditions and be expressed at early stages, before the primary tumor has spread.

“At this stage, few circulating biomarkers have been found that are both sensitive and specific for early-stage disease,” said Dr. Shroyer.

But there are a few promising examples under investigation in humans:

Prostate cancer. Researchers at the University of Michigan have developed a urine test that detects high-grade prostate cancer more accurately than existing tests, including PHI, SelectMDx, 4Kscore, EPI, MPS, and IsoPSA.

The MyProstateScore 2.0 (MPS2) test, which looks for 18 genes associated with high-grade tumors, could reduce unnecessary biopsies in men with elevated prostate-specific antigen levels, according to a paper published in JAMA Oncology.

It makes sense. The prostate gland secretes fluid that becomes part of the semen, traces of which enter urine. After a digital rectal exam, even more prostate fluid enters the urine. If a patient has prostate cancer, genetic material from the cancer cells will infiltrate the urine.

In the MPS2 test, researchers used polymerase chain reaction (PCR) testing in urine. “The technology used for COVID PCR is essentially the same as the PCR used to detect transcripts associated with high-grade prostate cancer in urine,” said study author Arul Chinnaiyan, MD, PhD, director of the Michigan Center for Translational Pathology at the University of Michigan, Ann Arbor. “In the case of the MPS2 test, we are doing PCR on 18 genes simultaneously on urine samples.”

A statistical model uses levels of that genetic material to predict the risk for high-grade disease, helping doctors decide what to do next. At 95% sensitivity, the MPS2 model could eliminate 35%-45% of unnecessary biopsies, compared with 15%-30% for the other tests, and reduce repeat biopsies by 46%-51%, compared with 9%-21% for the other tests.

Head and neck cancer. In a paper published in JCI Insight, researchers described a test that finds ultra-short fragments of DNA in urine to enable early detection of head and neck cancers caused by human papillomavirus.

“Our data show that a relatively small volume of urine (30-60 mL) gives overall detection results comparable to a tube of blood,” said study author Muneesh Tewari, MD, PhD, professor of hematology and oncology at the University of Michigan .

A larger volume of urine could potentially “make cancer detection even more sensitive than blood,” Dr. Tewari said, “allowing cancers to be detected at the earliest stages when they are more curable.”

The team used a technique called droplet digital PCR to detect DNA fragments that are “ultra-short” (less than 50 base pairs long) and usually missed by conventional PCR testing. This transrenal cell-free tumor DNA, which travels from the tumor into the bloodstream, is broken down small enough to pass through the kidneys and into the urine. But the fragments are still long enough to carry information about the tumor’s genetic signature.

This test could spot cancer before a tumor grows big enough — about a centimeter wide and carrying a billion cells — to spot on a CT scan or other imaging test. “When we are instead detecting fragments of DNA released from a tumor,” said Dr. Tewari, “our testing methods are very sensitive and can detect DNA in urine that came from just 5-10 cells in a tumor that died and released their DNA into the blood, which then made its way into the urine.”

Pancreatic cancer. Pancreatic ductal adenocarcinoma is one of the deadliest cancers, largely because it is diagnosed so late. A urine panel now in clinical trials could help doctors diagnose the cancer before it has spread so more people can have the tumor surgically removed, improving prognosis.

Using enzyme-linked immunosorbent assay test, a common lab method that detects antibodies and other proteins, the team measured expression levels for three genes (LYVE1, REG1B, and TFF1) in urine samples collected from people up to 5 years before they were diagnosed with pancreatic cancer. The researchers combined this result with patients’ urinary creatinine levels, a common component of existing urinalysis, and their age to develop a risk score.

This score performed similarly to an existing blood test, CA19-9, in predicting patients’ risk for pancreatic cancer up to 1 year before diagnosis. When combined with CA19-9, the urinary panel helped spot cancer up to 2 years before diagnosis.

According to a paper in the International Journal of Cancer, “the urine panel and affiliated PancRISK are currently being validated in a prospective clinical study (UroPanc).” If all goes well, they could be implemented in clinical practice in a few years as a “noninvasive stratification tool” to identify patients for further testing, speeding up diagnosis, and saving lives.

Limitations and Promises

Each cancer type is different, and more research is needed to map out which substances in urine predict which cancers and to develop tests for mass adoption. “There are medical and technological hurdles to the large-scale implementation of urine analysis for complex diseases such as cancer,” said Dr. Wong.

One possibility: Scientists and clinicians could collaborate and use artificial intelligence techniques to combine urine test results with other data.

“It is likely that future diagnostics may combine urine with other biological samples such as feces and saliva, among others,” said Dr. Wong. “This is especially true when novel data science and machine learning techniques can integrate comprehensive data from patients that span genetic, proteomic, metabolic, microbiomic, and even behavioral data to evaluate a patient’s condition.”

One thing that excites Dr. Tewari about urine-based cancer testing: “We think it could be especially impactful for patients living in rural areas or other areas with less access to healthcare services,” he said.
 

A version of this article appeared on Medscape.com.

Large language models (LLM) such as ChatGPT have shown mixed results in the quality of their responses to consumer questions about cancer.

One recent study found AI chatbots to churn out incomplete, inaccurate, or even nonsensical cancer treatment recommendations, while another found them to generate largely accurate — if technical — responses to the most common cancer questions.

While researchers have seen success with purpose-built chatbots created to address patient concerns about specific cancers, the consensus to date has been that the generalized models like ChatGPT remain works in progress and that physicians should avoid pointing patients to them, for now.

Yet new findings suggest that these chatbots may do better than individual physicians, at least on some measures, when it comes to answering queries about cancer. For research published May 16 in JAMA Oncology (doi: 10.1001/jamaoncol.2024.0836), David Chen, a medical student at the University of Toronto, and his colleagues, isolated a random sample of 200 questions related to cancer care addressed to doctors on the public online forum Reddit. They then compared responses from oncologists with responses generated by three different AI chatbots. The blinded responses were rated for quality, readability, and empathy by six physicians, including oncologists and palliative and supportive care specialists.

Mr. Chen and colleagues’ research was modeled after a 2023 study that measured the quality of physician responses compared with chatbots for general medicine questions addressed to doctors on Reddit. That study found that the chatbots produced more empathetic-sounding answers, something Mr. Chen’s study also found. The best-performing chatbot in Mr. Chen and colleagues’ study, Claude AI, performed significantly higher than the Reddit physicians on all the domains evaluated: quality, empathy, and readability.
 

Q&A With Author of New Research

Mr. Chen discussed his new study’s implications during an interview with this news organization.

Question: What is novel about this study?

Mr. Chen: We’ve seen many evaluations of chatbots that test for medical accuracy, but this study occurs in the domain of oncology care, where there are unique psychosocial and emotional considerations that are not precisely reflected in a general medicine setting. In effect, this study is putting these chatbots through a harder challenge.



Question: Why would chatbot responses seem more empathetic than those of physicians?

Mr. Chen: With the physician responses that we observed in our sample data set, we saw that there was very high variation of amount of apparent effort [in the physician responses]. Some physicians would put in a lot of time and effort, thinking through their response, and others wouldn’t do so as much. These chatbots don’t face fatigue the way humans do, or burnout. So they’re able to consistently provide responses with less variation in empathy.



Question: Do chatbots just seem empathetic because they are chattier?

Mr. Chen: We did think of verbosity as a potential confounder in this study. So we set a word count limit for the chatbot responses to keep it in the range of the physician responses. That way, verbosity was no longer a significant factor.



Question: How were quality and empathy measured by the reviewers?

Mr. Chen: For our study we used two teams of readers, each team composed of three physicians. In terms of the actual metrics we used, they were pilot metrics. There are no well-defined measurement scales or checklists that we could use to measure empathy. This is an emerging field of research. So we came up by consensus with our own set of ratings, and we feel that this is an area for the research to define a standardized set of guidelines.

Another novel aspect of this study is that we separated out different dimensions of quality and empathy. A quality response didn’t just mean it was medically accurate — quality also had to do with the focus and completeness of the response.

With empathy there are cognitive and emotional dimensions. Cognitive empathy uses critical thinking to understand the person’s emotions and thoughts and then adjusting a response to fit that. A patient may not want the best medically indicated treatment for their condition, because they want to preserve their quality of life. The chatbot may be able to adjust its recommendation with consideration of some of those humanistic elements that the patient is presenting with.

Emotional empathy is more about being supportive of the patient’s emotions by using expressions like ‘I understand where you’re coming from.’ or, ‘I can see how that makes you feel.’



Question: Why would physicians, not patients, be the best evaluators of empathy?

Mr. Chen: We’re actually very interested in evaluating patient ratings of empathy. We are conducting a follow-up study that evaluates patient ratings of empathy to the same set of chatbot and physician responses,to see if there are differences.



Question: Should cancer patients go ahead and consult chatbots?

Mr. Chen: Although we did observe increases in all of the metrics compared with physicians, this is a very specialized evaluation scenario where we’re using these Reddit questions and responses.

Naturally, we would need to do a trial, a head to head randomized comparison of physicians versus chatbots.

This pilot study does highlight the promising potential of these chatbots to suggest responses. But we can’t fully recommend that they should be used as standalone clinical tools without physicians.

This Q&A was edited for clarity.

Large language models (LLM) such as ChatGPT have shown mixed results in the quality of their responses to consumer questions about cancer.

One recent study found AI chatbots to churn out incomplete, inaccurate, or even nonsensical cancer treatment recommendations, while another found them to generate largely accurate — if technical — responses to the most common cancer questions.

While researchers have seen success with purpose-built chatbots created to address patient concerns about specific cancers, the consensus to date has been that the generalized models like ChatGPT remain works in progress and that physicians should avoid pointing patients to them, for now.

Yet new findings suggest that these chatbots may do better than individual physicians, at least on some measures, when it comes to answering queries about cancer. For research published May 16 in JAMA Oncology (doi: 10.1001/jamaoncol.2024.0836), David Chen, a medical student at the University of Toronto, and his colleagues, isolated a random sample of 200 questions related to cancer care addressed to doctors on the public online forum Reddit. They then compared responses from oncologists with responses generated by three different AI chatbots. The blinded responses were rated for quality, readability, and empathy by six physicians, including oncologists and palliative and supportive care specialists.

Mr. Chen and colleagues’ research was modeled after a 2023 study that measured the quality of physician responses compared with chatbots for general medicine questions addressed to doctors on Reddit. That study found that the chatbots produced more empathetic-sounding answers, something Mr. Chen’s study also found. The best-performing chatbot in Mr. Chen and colleagues’ study, Claude AI, performed significantly higher than the Reddit physicians on all the domains evaluated: quality, empathy, and readability.
 

Q&A With Author of New Research

Mr. Chen discussed his new study’s implications during an interview with this news organization.

Question: What is novel about this study?

Mr. Chen: We’ve seen many evaluations of chatbots that test for medical accuracy, but this study occurs in the domain of oncology care, where there are unique psychosocial and emotional considerations that are not precisely reflected in a general medicine setting. In effect, this study is putting these chatbots through a harder challenge.



Question: Why would chatbot responses seem more empathetic than those of physicians?

Mr. Chen: With the physician responses that we observed in our sample data set, we saw that there was very high variation of amount of apparent effort [in the physician responses]. Some physicians would put in a lot of time and effort, thinking through their response, and others wouldn’t do so as much. These chatbots don’t face fatigue the way humans do, or burnout. So they’re able to consistently provide responses with less variation in empathy.



Question: Do chatbots just seem empathetic because they are chattier?

Mr. Chen: We did think of verbosity as a potential confounder in this study. So we set a word count limit for the chatbot responses to keep it in the range of the physician responses. That way, verbosity was no longer a significant factor.



Question: How were quality and empathy measured by the reviewers?

Mr. Chen: For our study we used two teams of readers, each team composed of three physicians. In terms of the actual metrics we used, they were pilot metrics. There are no well-defined measurement scales or checklists that we could use to measure empathy. This is an emerging field of research. So we came up by consensus with our own set of ratings, and we feel that this is an area for the research to define a standardized set of guidelines.

Another novel aspect of this study is that we separated out different dimensions of quality and empathy. A quality response didn’t just mean it was medically accurate — quality also had to do with the focus and completeness of the response.

With empathy there are cognitive and emotional dimensions. Cognitive empathy uses critical thinking to understand the person’s emotions and thoughts and then adjusting a response to fit that. A patient may not want the best medically indicated treatment for their condition, because they want to preserve their quality of life. The chatbot may be able to adjust its recommendation with consideration of some of those humanistic elements that the patient is presenting with.

Emotional empathy is more about being supportive of the patient’s emotions by using expressions like ‘I understand where you’re coming from.’ or, ‘I can see how that makes you feel.’



Question: Why would physicians, not patients, be the best evaluators of empathy?

Mr. Chen: We’re actually very interested in evaluating patient ratings of empathy. We are conducting a follow-up study that evaluates patient ratings of empathy to the same set of chatbot and physician responses,to see if there are differences.



Question: Should cancer patients go ahead and consult chatbots?

Mr. Chen: Although we did observe increases in all of the metrics compared with physicians, this is a very specialized evaluation scenario where we’re using these Reddit questions and responses.

Naturally, we would need to do a trial, a head to head randomized comparison of physicians versus chatbots.

This pilot study does highlight the promising potential of these chatbots to suggest responses. But we can’t fully recommend that they should be used as standalone clinical tools without physicians.

This Q&A was edited for clarity.

Large language models (LLM) such as ChatGPT have shown mixed results in the quality of their responses to consumer questions about cancer.

One recent study found AI chatbots to churn out incomplete, inaccurate, or even nonsensical cancer treatment recommendations, while another found them to generate largely accurate — if technical — responses to the most common cancer questions.

While researchers have seen success with purpose-built chatbots created to address patient concerns about specific cancers, the consensus to date has been that the generalized models like ChatGPT remain works in progress and that physicians should avoid pointing patients to them, for now.

Yet new findings suggest that these chatbots may do better than individual physicians, at least on some measures, when it comes to answering queries about cancer. For research published May 16 in JAMA Oncology (doi: 10.1001/jamaoncol.2024.0836), David Chen, a medical student at the University of Toronto, and his colleagues, isolated a random sample of 200 questions related to cancer care addressed to doctors on the public online forum Reddit. They then compared responses from oncologists with responses generated by three different AI chatbots. The blinded responses were rated for quality, readability, and empathy by six physicians, including oncologists and palliative and supportive care specialists.

Mr. Chen and colleagues’ research was modeled after a 2023 study that measured the quality of physician responses compared with chatbots for general medicine questions addressed to doctors on Reddit. That study found that the chatbots produced more empathetic-sounding answers, something Mr. Chen’s study also found. The best-performing chatbot in Mr. Chen and colleagues’ study, Claude AI, performed significantly higher than the Reddit physicians on all the domains evaluated: quality, empathy, and readability.
 

Q&A With Author of New Research

Mr. Chen discussed his new study’s implications during an interview with this news organization.

Question: What is novel about this study?

Mr. Chen: We’ve seen many evaluations of chatbots that test for medical accuracy, but this study occurs in the domain of oncology care, where there are unique psychosocial and emotional considerations that are not precisely reflected in a general medicine setting. In effect, this study is putting these chatbots through a harder challenge.



Question: Why would chatbot responses seem more empathetic than those of physicians?

Mr. Chen: With the physician responses that we observed in our sample data set, we saw that there was very high variation of amount of apparent effort [in the physician responses]. Some physicians would put in a lot of time and effort, thinking through their response, and others wouldn’t do so as much. These chatbots don’t face fatigue the way humans do, or burnout. So they’re able to consistently provide responses with less variation in empathy.



Question: Do chatbots just seem empathetic because they are chattier?

Mr. Chen: We did think of verbosity as a potential confounder in this study. So we set a word count limit for the chatbot responses to keep it in the range of the physician responses. That way, verbosity was no longer a significant factor.



Question: How were quality and empathy measured by the reviewers?

Mr. Chen: For our study we used two teams of readers, each team composed of three physicians. In terms of the actual metrics we used, they were pilot metrics. There are no well-defined measurement scales or checklists that we could use to measure empathy. This is an emerging field of research. So we came up by consensus with our own set of ratings, and we feel that this is an area for the research to define a standardized set of guidelines.

Another novel aspect of this study is that we separated out different dimensions of quality and empathy. A quality response didn’t just mean it was medically accurate — quality also had to do with the focus and completeness of the response.

With empathy there are cognitive and emotional dimensions. Cognitive empathy uses critical thinking to understand the person’s emotions and thoughts and then adjusting a response to fit that. A patient may not want the best medically indicated treatment for their condition, because they want to preserve their quality of life. The chatbot may be able to adjust its recommendation with consideration of some of those humanistic elements that the patient is presenting with.

Emotional empathy is more about being supportive of the patient’s emotions by using expressions like ‘I understand where you’re coming from.’ or, ‘I can see how that makes you feel.’



Question: Why would physicians, not patients, be the best evaluators of empathy?

Mr. Chen: We’re actually very interested in evaluating patient ratings of empathy. We are conducting a follow-up study that evaluates patient ratings of empathy to the same set of chatbot and physician responses,to see if there are differences.



Question: Should cancer patients go ahead and consult chatbots?

Mr. Chen: Although we did observe increases in all of the metrics compared with physicians, this is a very specialized evaluation scenario where we’re using these Reddit questions and responses.

Naturally, we would need to do a trial, a head to head randomized comparison of physicians versus chatbots.

This pilot study does highlight the promising potential of these chatbots to suggest responses. But we can’t fully recommend that they should be used as standalone clinical tools without physicians.

This Q&A was edited for clarity.

SAN DIEGO — Compared with medical oncologists, dermatologists were more likely to correctly classify and grade dermatologic adverse events from cancer therapies, results from a multicenter survey showed.

“New cancer therapies have brought a diversity of treatment-related dermatologic adverse events (dAEs) beyond those experienced with conventional chemotherapy, which has demanded an evolving assessment of toxicities,” researchers led by Nicole R. LeBoeuf, MD, MPH, of the Department of Dermatology at Brigham and Women’s Hospital and the Center for Cutaneous Oncology at the Dana-Farber Brigham Cancer Center, Boston, wrote in a poster presented at the American Academy of Dermatology annual meeting.

The authors noted that “Version 5.0 of the Common Terminology Criteria for Adverse Events (CTCAE v5.0)” serves as the current, broadly accepted criteria for classification and grading during routine medical care and clinical trials. But despite extensive utilization of CTCAE, there is little data regarding its application.”

To evaluate how CTCAE is being used in clinical practice, they sent a four-case survey of dAEs to 81 dermatologists and 182 medical oncologists at six US-based academic institutions. For three of the cases, respondents were asked to classify and grade morbilliform, psoriasiform, and papulopustular rashes based on a review of photographs and text descriptions. For the fourth case, respondents were asked to grade a dAE using only a clinic note text description. The researchers used chi-square tests in R software to compare survey responses.

Compared with medical oncologists, dermatologists were significantly more likely to provide correct responses in characterizing morbilliform and psoriasiform eruptions. “As low as 12%” of medical oncologists were correct, and “as low as 87%” of dermatologists were correct (P < .001). Similarly, dermatologists were significantly more likely to grade the psoriasiform, papulopustular, and written cases correctly compared with medical oncologists (P < .001 for all associations).

“These cases demonstrated poor concordance of classification and grading between specialties and across medical oncology,” the authors concluded in their poster, noting that 87% of medical oncologists were interested in additional educational tools on dAEs. “With correct classification as low as 12%, medical oncologists may have more difficulty delivering appropriate, toxicity-specific therapy and may consider banal eruptions dangerous.”

Poor concordance of grading among the two groups of clinicians “raises the question of whether CTCAE v5.0 is an appropriate determinant for patient continuation on therapy or in trials,” they added. “As anticancer therapy becomes more complex — with new toxicities from novel agents and combinations — we must ensure we have a grading system that is valid across investigators and does not harm patients by instituting unnecessary treatment stops.”

Future studies, they said, “can explore what interventions beyond involvement of dermatologists improve classification and grading in practice.”

Adam Friedman, MD, professor and chair of dermatology at George Washington University, Washington, who was asked to comment on the study, noted that with the continued expansion and introduction of new targeted and immunotherapies in the oncology space, “you can be sure we will continue to appreciate the importance and value of the field of supportive oncodermatology, as hair, skin, and nails are almost guaranteed collateral damage in this story.

“Ensuring early identification and consistent grading severity is not only important for the plethora of patients who are currently developing the litany of cutaneous adverse events but to evaluate potential mitigation strategies and even push along countermeasures down the FDA approval pathway,” Dr. Friedman said. In this study, the investigators demonstrated that work “is sorely needed, not just in dermatology but even more so for our colleagues across the aisle. A central tenet of supportive oncodermatology must also be education for all stakeholders, and the good news is our oncology partners will welcome it.”

Dr. LeBoeuf disclosed that she is a consultant to and has received honoraria from Bayer, Seattle Genetics, Sanofi, Silverback, Fortress Biotech, and Synox Therapeutics outside the submitted work. No other authors reported having financial disclosures. Dr. Friedman directs the supportive oncodermatology program at GW that received independent funding from La Roche-Posay.
 

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

SAN DIEGO — Compared with medical oncologists, dermatologists were more likely to correctly classify and grade dermatologic adverse events from cancer therapies, results from a multicenter survey showed.

“New cancer therapies have brought a diversity of treatment-related dermatologic adverse events (dAEs) beyond those experienced with conventional chemotherapy, which has demanded an evolving assessment of toxicities,” researchers led by Nicole R. LeBoeuf, MD, MPH, of the Department of Dermatology at Brigham and Women’s Hospital and the Center for Cutaneous Oncology at the Dana-Farber Brigham Cancer Center, Boston, wrote in a poster presented at the American Academy of Dermatology annual meeting.

The authors noted that “Version 5.0 of the Common Terminology Criteria for Adverse Events (CTCAE v5.0)” serves as the current, broadly accepted criteria for classification and grading during routine medical care and clinical trials. But despite extensive utilization of CTCAE, there is little data regarding its application.”

To evaluate how CTCAE is being used in clinical practice, they sent a four-case survey of dAEs to 81 dermatologists and 182 medical oncologists at six US-based academic institutions. For three of the cases, respondents were asked to classify and grade morbilliform, psoriasiform, and papulopustular rashes based on a review of photographs and text descriptions. For the fourth case, respondents were asked to grade a dAE using only a clinic note text description. The researchers used chi-square tests in R software to compare survey responses.

Compared with medical oncologists, dermatologists were significantly more likely to provide correct responses in characterizing morbilliform and psoriasiform eruptions. “As low as 12%” of medical oncologists were correct, and “as low as 87%” of dermatologists were correct (P < .001). Similarly, dermatologists were significantly more likely to grade the psoriasiform, papulopustular, and written cases correctly compared with medical oncologists (P < .001 for all associations).

“These cases demonstrated poor concordance of classification and grading between specialties and across medical oncology,” the authors concluded in their poster, noting that 87% of medical oncologists were interested in additional educational tools on dAEs. “With correct classification as low as 12%, medical oncologists may have more difficulty delivering appropriate, toxicity-specific therapy and may consider banal eruptions dangerous.”

Poor concordance of grading among the two groups of clinicians “raises the question of whether CTCAE v5.0 is an appropriate determinant for patient continuation on therapy or in trials,” they added. “As anticancer therapy becomes more complex — with new toxicities from novel agents and combinations — we must ensure we have a grading system that is valid across investigators and does not harm patients by instituting unnecessary treatment stops.”

Future studies, they said, “can explore what interventions beyond involvement of dermatologists improve classification and grading in practice.”

Adam Friedman, MD, professor and chair of dermatology at George Washington University, Washington, who was asked to comment on the study, noted that with the continued expansion and introduction of new targeted and immunotherapies in the oncology space, “you can be sure we will continue to appreciate the importance and value of the field of supportive oncodermatology, as hair, skin, and nails are almost guaranteed collateral damage in this story.

“Ensuring early identification and consistent grading severity is not only important for the plethora of patients who are currently developing the litany of cutaneous adverse events but to evaluate potential mitigation strategies and even push along countermeasures down the FDA approval pathway,” Dr. Friedman said. In this study, the investigators demonstrated that work “is sorely needed, not just in dermatology but even more so for our colleagues across the aisle. A central tenet of supportive oncodermatology must also be education for all stakeholders, and the good news is our oncology partners will welcome it.”

Dr. LeBoeuf disclosed that she is a consultant to and has received honoraria from Bayer, Seattle Genetics, Sanofi, Silverback, Fortress Biotech, and Synox Therapeutics outside the submitted work. No other authors reported having financial disclosures. Dr. Friedman directs the supportive oncodermatology program at GW that received independent funding from La Roche-Posay.
 

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

SAN DIEGO — Compared with medical oncologists, dermatologists were more likely to correctly classify and grade dermatologic adverse events from cancer therapies, results from a multicenter survey showed.

“New cancer therapies have brought a diversity of treatment-related dermatologic adverse events (dAEs) beyond those experienced with conventional chemotherapy, which has demanded an evolving assessment of toxicities,” researchers led by Nicole R. LeBoeuf, MD, MPH, of the Department of Dermatology at Brigham and Women’s Hospital and the Center for Cutaneous Oncology at the Dana-Farber Brigham Cancer Center, Boston, wrote in a poster presented at the American Academy of Dermatology annual meeting.

The authors noted that “Version 5.0 of the Common Terminology Criteria for Adverse Events (CTCAE v5.0)” serves as the current, broadly accepted criteria for classification and grading during routine medical care and clinical trials. But despite extensive utilization of CTCAE, there is little data regarding its application.”

To evaluate how CTCAE is being used in clinical practice, they sent a four-case survey of dAEs to 81 dermatologists and 182 medical oncologists at six US-based academic institutions. For three of the cases, respondents were asked to classify and grade morbilliform, psoriasiform, and papulopustular rashes based on a review of photographs and text descriptions. For the fourth case, respondents were asked to grade a dAE using only a clinic note text description. The researchers used chi-square tests in R software to compare survey responses.

Compared with medical oncologists, dermatologists were significantly more likely to provide correct responses in characterizing morbilliform and psoriasiform eruptions. “As low as 12%” of medical oncologists were correct, and “as low as 87%” of dermatologists were correct (P < .001). Similarly, dermatologists were significantly more likely to grade the psoriasiform, papulopustular, and written cases correctly compared with medical oncologists (P < .001 for all associations).

“These cases demonstrated poor concordance of classification and grading between specialties and across medical oncology,” the authors concluded in their poster, noting that 87% of medical oncologists were interested in additional educational tools on dAEs. “With correct classification as low as 12%, medical oncologists may have more difficulty delivering appropriate, toxicity-specific therapy and may consider banal eruptions dangerous.”

Poor concordance of grading among the two groups of clinicians “raises the question of whether CTCAE v5.0 is an appropriate determinant for patient continuation on therapy or in trials,” they added. “As anticancer therapy becomes more complex — with new toxicities from novel agents and combinations — we must ensure we have a grading system that is valid across investigators and does not harm patients by instituting unnecessary treatment stops.”

Future studies, they said, “can explore what interventions beyond involvement of dermatologists improve classification and grading in practice.”

Adam Friedman, MD, professor and chair of dermatology at George Washington University, Washington, who was asked to comment on the study, noted that with the continued expansion and introduction of new targeted and immunotherapies in the oncology space, “you can be sure we will continue to appreciate the importance and value of the field of supportive oncodermatology, as hair, skin, and nails are almost guaranteed collateral damage in this story.

“Ensuring early identification and consistent grading severity is not only important for the plethora of patients who are currently developing the litany of cutaneous adverse events but to evaluate potential mitigation strategies and even push along countermeasures down the FDA approval pathway,” Dr. Friedman said. In this study, the investigators demonstrated that work “is sorely needed, not just in dermatology but even more so for our colleagues across the aisle. A central tenet of supportive oncodermatology must also be education for all stakeholders, and the good news is our oncology partners will welcome it.”

Dr. LeBoeuf disclosed that she is a consultant to and has received honoraria from Bayer, Seattle Genetics, Sanofi, Silverback, Fortress Biotech, and Synox Therapeutics outside the submitted work. No other authors reported having financial disclosures. Dr. Friedman directs the supportive oncodermatology program at GW that received independent funding from La Roche-Posay.
 

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

TOPLINE:

Overall, patients with solid tumors who receive an investigational cancer drug experience small progression-free survival (PFS) and overall survival benefits but much higher toxicity than those who receive a control intervention.

METHODOLOGY:

• The view that patients with cancer benefit from access to investigational drugs in the clinical trial setting is widely held but does necessarily align with trial findings, which often show limited evidence of a clinical benefit. First, most investigational treatments assessed in clinical trials fail to gain regulatory approval, and the minority that are approved tend to offer minimal clinical benefit, experts explained.
• To estimate the survival benefit and toxicities associated with receiving experimental treatments, researchers conducted a meta-analysis of 128 trials comprising 141 comparisons of an investigational drug and a control treatment, which included immunotherapies and targeted therapies.
• The analysis included 42 trials in non–small cell lung cancer (NSCLC), 37 in breast cancer, 15 in hepatobiliary cancer, 13 in pancreatic cancer, 12 in colorectal cancer, and 10 in prostate cancer, involving a total of 47,050 patients.
• The primary outcome was PFS and secondary outcomes were overall survival and grades 3-5 serious adverse events.

TAKEAWAY:

• Overall, the experimental treatment was associated with a 20% improvement in PFS (pooled hazard ratio [HR], 0.80), corresponding to a median 1.25-month PFS advantage. The PFS benefit was seen across all cancer types, except pancreatic cancer.
• Overall survival improved by 8% with experimental agents (HR, 0.92), corresponding to 1.18 additional months. A significant overall survival benefit was seen across NSCLC, breast cancer, and hepatobiliary cancer trials but not pancreatic, prostate, colorectal cancer trials.
• Patients in the experimental intervention group, however, experienced much higher risk for grade 3-5 serious adverse events (risk ratio [RR], 1.27), corresponding to 7.40% increase in absolute risk. The greater risk for serious adverse events was significant for all indications except prostate cancer (RR, 1.13; 95% CI, 0.91-1.40).

IN PRACTICE:

“We believe our findings are best interpreted as suggesting that access to experimental interventions that have not yet received full FDA approval is associated with a marginal but nonzero clinical benefit,” the authors wrote. 

“Although our findings seem to reflect poorly on trials as a vehicle for extending survival for participants, they have reassuring implications for clinical investigators, policymakers, and institutional review boards,” the researchers said, explaining that this “scenario allows clinical trials to continue to pursue promising new treatments — supporting incremental advances that sum to large gains over extended periods of research — without disadvantaging patients in comparator groups.”

SOURCE: 

Renata Iskander, MSc, of McGill University, Montreal, Quebec, Canada, led this work, which was published online on April 29, 2024, in Annals of Internal Medicine.

LIMITATIONS:

There was high heterogeneity across studies due to variations in drugs tested, comparators used, and populations involved. The use of comparators below standard care could have inflated survival benefits. Additionally, data collected from ClinicalTrials.gov might be biased due to some trials not being reported. 

DISCLOSURES:

Canadian Institutes of Health Research supported this work. The authors received grants for this work from McGill University, Rossy Cancer Network, and National Science Foundation. One author received consulting fees outside this work. The other authors declared no competing interests.

A version of this article appeared on Medscape.com.

TOPLINE:

Overall, patients with solid tumors who receive an investigational cancer drug experience small progression-free survival (PFS) and overall survival benefits but much higher toxicity than those who receive a control intervention.

METHODOLOGY:

• The view that patients with cancer benefit from access to investigational drugs in the clinical trial setting is widely held but does necessarily align with trial findings, which often show limited evidence of a clinical benefit. First, most investigational treatments assessed in clinical trials fail to gain regulatory approval, and the minority that are approved tend to offer minimal clinical benefit, experts explained.
• To estimate the survival benefit and toxicities associated with receiving experimental treatments, researchers conducted a meta-analysis of 128 trials comprising 141 comparisons of an investigational drug and a control treatment, which included immunotherapies and targeted therapies.
• The analysis included 42 trials in non–small cell lung cancer (NSCLC), 37 in breast cancer, 15 in hepatobiliary cancer, 13 in pancreatic cancer, 12 in colorectal cancer, and 10 in prostate cancer, involving a total of 47,050 patients.
• The primary outcome was PFS and secondary outcomes were overall survival and grades 3-5 serious adverse events.

TAKEAWAY:

• Overall, the experimental treatment was associated with a 20% improvement in PFS (pooled hazard ratio [HR], 0.80), corresponding to a median 1.25-month PFS advantage. The PFS benefit was seen across all cancer types, except pancreatic cancer.
• Overall survival improved by 8% with experimental agents (HR, 0.92), corresponding to 1.18 additional months. A significant overall survival benefit was seen across NSCLC, breast cancer, and hepatobiliary cancer trials but not pancreatic, prostate, colorectal cancer trials.
• Patients in the experimental intervention group, however, experienced much higher risk for grade 3-5 serious adverse events (risk ratio [RR], 1.27), corresponding to 7.40% increase in absolute risk. The greater risk for serious adverse events was significant for all indications except prostate cancer (RR, 1.13; 95% CI, 0.91-1.40).

IN PRACTICE:

“We believe our findings are best interpreted as suggesting that access to experimental interventions that have not yet received full FDA approval is associated with a marginal but nonzero clinical benefit,” the authors wrote. 

“Although our findings seem to reflect poorly on trials as a vehicle for extending survival for participants, they have reassuring implications for clinical investigators, policymakers, and institutional review boards,” the researchers said, explaining that this “scenario allows clinical trials to continue to pursue promising new treatments — supporting incremental advances that sum to large gains over extended periods of research — without disadvantaging patients in comparator groups.”

SOURCE: 

Renata Iskander, MSc, of McGill University, Montreal, Quebec, Canada, led this work, which was published online on April 29, 2024, in Annals of Internal Medicine.

LIMITATIONS:

There was high heterogeneity across studies due to variations in drugs tested, comparators used, and populations involved. The use of comparators below standard care could have inflated survival benefits. Additionally, data collected from ClinicalTrials.gov might be biased due to some trials not being reported. 

DISCLOSURES:

Canadian Institutes of Health Research supported this work. The authors received grants for this work from McGill University, Rossy Cancer Network, and National Science Foundation. One author received consulting fees outside this work. The other authors declared no competing interests.

A version of this article appeared on Medscape.com.

TOPLINE:

Overall, patients with solid tumors who receive an investigational cancer drug experience small progression-free survival (PFS) and overall survival benefits but much higher toxicity than those who receive a control intervention.

METHODOLOGY:

• The view that patients with cancer benefit from access to investigational drugs in the clinical trial setting is widely held but does necessarily align with trial findings, which often show limited evidence of a clinical benefit. First, most investigational treatments assessed in clinical trials fail to gain regulatory approval, and the minority that are approved tend to offer minimal clinical benefit, experts explained.
• To estimate the survival benefit and toxicities associated with receiving experimental treatments, researchers conducted a meta-analysis of 128 trials comprising 141 comparisons of an investigational drug and a control treatment, which included immunotherapies and targeted therapies.
• The analysis included 42 trials in non–small cell lung cancer (NSCLC), 37 in breast cancer, 15 in hepatobiliary cancer, 13 in pancreatic cancer, 12 in colorectal cancer, and 10 in prostate cancer, involving a total of 47,050 patients.
• The primary outcome was PFS and secondary outcomes were overall survival and grades 3-5 serious adverse events.

TAKEAWAY:

• Overall, the experimental treatment was associated with a 20% improvement in PFS (pooled hazard ratio [HR], 0.80), corresponding to a median 1.25-month PFS advantage. The PFS benefit was seen across all cancer types, except pancreatic cancer.
• Overall survival improved by 8% with experimental agents (HR, 0.92), corresponding to 1.18 additional months. A significant overall survival benefit was seen across NSCLC, breast cancer, and hepatobiliary cancer trials but not pancreatic, prostate, colorectal cancer trials.
• Patients in the experimental intervention group, however, experienced much higher risk for grade 3-5 serious adverse events (risk ratio [RR], 1.27), corresponding to 7.40% increase in absolute risk. The greater risk for serious adverse events was significant for all indications except prostate cancer (RR, 1.13; 95% CI, 0.91-1.40).

IN PRACTICE:

“We believe our findings are best interpreted as suggesting that access to experimental interventions that have not yet received full FDA approval is associated with a marginal but nonzero clinical benefit,” the authors wrote. 

“Although our findings seem to reflect poorly on trials as a vehicle for extending survival for participants, they have reassuring implications for clinical investigators, policymakers, and institutional review boards,” the researchers said, explaining that this “scenario allows clinical trials to continue to pursue promising new treatments — supporting incremental advances that sum to large gains over extended periods of research — without disadvantaging patients in comparator groups.”

SOURCE: 

Renata Iskander, MSc, of McGill University, Montreal, Quebec, Canada, led this work, which was published online on April 29, 2024, in Annals of Internal Medicine.

LIMITATIONS:

There was high heterogeneity across studies due to variations in drugs tested, comparators used, and populations involved. The use of comparators below standard care could have inflated survival benefits. Additionally, data collected from ClinicalTrials.gov might be biased due to some trials not being reported. 

DISCLOSURES:

Canadian Institutes of Health Research supported this work. The authors received grants for this work from McGill University, Rossy Cancer Network, and National Science Foundation. One author received consulting fees outside this work. The other authors declared no competing interests.

A version of this article appeared on Medscape.com.

Health-related social needs and medical financial hardship are associated with increased risk of mortality in adult cancer survivors, based on data from more than 10,000 individuals.

Little is known about the specific association between health-related social needs (HRSNs) and mortality risk even though HRSNs, defined as challenges in affording food, housing, and other necessities of daily living, are potential challenges for cancer survivors, wrote Zhiyuan Zheng, PhD, of the American Cancer Society, Atlanta, and colleagues.

A 2020 study by Dr. Zheng and colleagues published in the Journal of the National Comprehensive Cancer Network (NCCN) showed that food insecurity and financial worries had a negative impact on cancer survivorship. In the new study, published in Cancer, the researchers identified cancer survivors using the 2013-2018 National Health Interview Survey (NHIS) and the NHIS Mortality File through December 31, 2019. The researchers examined mortality using the data from the Centers for Disease Control and Prevention’s National Death Index (NDI) through December 31, 2019, which links to the National Health Interview Survey Data used in the study.

Individuals’ HRSNs were categorized into three groups: severe, moderate, and minor/none. HRSNs included food insecurity and nonmedical financial concerns, such as housing costs (rent, mortgage). Medical financial hardship included material, psychological, and behavioral domains and was divided into three groups: 2-3 domains, 1 domain, or 0 domains.
 

What Are the Potential Financial Implications of this Research?

The high costs of cancer care often cause medical financial hardships for cancer survivors, and expenses also may cause psychological distress and nonmedical financial hardship as survivors try to make ends meet while facing medical bills, wrote Dr. Zheng and colleagues.

Policy makers are increasingly interested in adding HRSNs to insurance coverage; recent guidance from the Centers for Medicare & Medicaid Services (CMS) allows individual states to apply to provide nutrition and housing supports through state Medicaid programs, according to authors of a 2023 article published in JAMA Health Forum.

The new study adds to the understanding of how HRSNs impact people with cancer by examining the association with mortality risk, Yelak Biru, MSc, president and chief executive officer of the International Myeloma Foundation, said in an interview.

“This is a key area of study for addressing the disparities in treatments and outcomes that result in inequities,” said Mr. Biru, a patient advocate and multiple myeloma survivor who was not involved in the study.
 

What Does the New Study Show?

The new study characterized HRSNs in 5,855 adult cancer survivors aged 18-64 years and 5,918 aged 65-79 years. In the 18- to 64-year-old group, 25.5% reported moderate levels of HRSNs, and 18.3% reported severe HRSNs. In patients aged 65-79 years, 15.6% and 6.6% reported moderate HRSNs and severe HRSNs, respectively.

Severe HRSN was significantly associated with higher mortality risk in an adjusted analysis in patients aged 18-64 years (hazard ratio 2.00, P < .001).

Among adults aged 65-79 years, severe HRSN was not associated with higher mortality risk; however, in this older age group, those with 2-3 domains of medical financial hardship had significantly increased mortality risk compared with adults aged 65-79 years with zero domains of medical financial hardship (HR 1.58, P = .007).

Although the findings that HRSNs were associated with increased mortality risk, especially in the younger group, were not surprising, they serve as a call to action to address how HRSNs are contributing to cancer mortality, Mr. Biru said in an interview. “HRSNs, like food or housing insecurity, can lead to patients being unable to undergo the best treatment approach for their cancer,” he said.
 

What Are the Limitations and Research Gaps?

The study findings were limited by several factors including the use of self-reports to measure medical financial hardship, food insecurity, and nonmedical financial concerns in the NHIS, the researchers wrote in their discussion. More research with longer follow-up time beyond 1-5 years is needed, wrote Dr. Zheng and colleagues.

Studies also are needed to illustrate how patient navigation can help prevent patients from falling through the cracks with regard to social needs and financial hardships, Mr. Biru told this news organization.

Other areas for research include how addressing social needs affects health outcomes and whether programs designed to address social needs are effective, he said.

“Finally, qualitative research is needed to capture the lived experiences of cancer survivors facing these challenges. This knowledge can inform the development of more patient-centered interventions and policies that effectively address the social determinants of health and improve overall outcomes for all cancer survivors,” Mr. Biru said.
 

What Is the Takeaway Message for Clinicians?

HRSNs and financial hardship are significantly associated with increased risk of mortality in adult cancer survivors, Dr. Zheng and colleagues concluded. Looking ahead, comprehensive assessment of HRSNs and financial hardship may help clinicians connect patients with relevant services to mitigate the social and financial impacts of cancer, they wrote.

“The takeaway message for oncologists in practice is that addressing [HRSNs] and financial hardship is crucial for providing comprehensive and equitable cancer care,” Mr. Biru said during his interview.

“The impact of social determinants of health on cancer outcomes cannot be ignored, and oncologists play a vital role in identifying and addressing these needs,” he said. Sensitive, discussion-based screenings are needed to identify core needs such as food and transportation, but clinicians also can consider broader social factors and work with a team to connect patients to appropriate resources, he added.

“By recognizing the importance of HRSN screening and taking proactive steps to address these needs, oncologists can contribute to improving health outcomes, reducing healthcare disparities, and providing more equitable cancer care for their patients,” he said.
 

What Other Guidance Is Available?

“High-quality cancer care requires treating the whole person; measuring and addressing anything in their life that could result in poorer health outcomes is a key component of comprehensive care,” Mr. Biru emphasized.

In September 2023, the National Comprehensive Cancer Network (NCCN) convened a working group cochaired by Mr. Biru that developed recommendations for how oncology practices should routinely measure HRSNs (NCCN.org/social-needs).

“The working group proposed that every cancer patient be assessed for food, transportation access, and financial and housing security at least once a year, and be reassessed at every care transition point as well,” Mr. Biru said. Such screenings should include follow-up to connect patients with services to address any HRSNs they are experiencing, he added.

Lead author Dr. Zheng is employed by the American Cancer Society, which as a nonprofit receives funds from the public through fundraising and contributions, as well as some support from corporations and industry to support its mission programs and services. Mr. Biru had no financial conflicts to disclose.

Health-related social needs and medical financial hardship are associated with increased risk of mortality in adult cancer survivors, based on data from more than 10,000 individuals.

Little is known about the specific association between health-related social needs (HRSNs) and mortality risk even though HRSNs, defined as challenges in affording food, housing, and other necessities of daily living, are potential challenges for cancer survivors, wrote Zhiyuan Zheng, PhD, of the American Cancer Society, Atlanta, and colleagues.

A 2020 study by Dr. Zheng and colleagues published in the Journal of the National Comprehensive Cancer Network (NCCN) showed that food insecurity and financial worries had a negative impact on cancer survivorship. In the new study, published in Cancer, the researchers identified cancer survivors using the 2013-2018 National Health Interview Survey (NHIS) and the NHIS Mortality File through December 31, 2019. The researchers examined mortality using the data from the Centers for Disease Control and Prevention’s National Death Index (NDI) through December 31, 2019, which links to the National Health Interview Survey Data used in the study.

Individuals’ HRSNs were categorized into three groups: severe, moderate, and minor/none. HRSNs included food insecurity and nonmedical financial concerns, such as housing costs (rent, mortgage). Medical financial hardship included material, psychological, and behavioral domains and was divided into three groups: 2-3 domains, 1 domain, or 0 domains.
 

What Are the Potential Financial Implications of this Research?

The high costs of cancer care often cause medical financial hardships for cancer survivors, and expenses also may cause psychological distress and nonmedical financial hardship as survivors try to make ends meet while facing medical bills, wrote Dr. Zheng and colleagues.

Policy makers are increasingly interested in adding HRSNs to insurance coverage; recent guidance from the Centers for Medicare & Medicaid Services (CMS) allows individual states to apply to provide nutrition and housing supports through state Medicaid programs, according to authors of a 2023 article published in JAMA Health Forum.

The new study adds to the understanding of how HRSNs impact people with cancer by examining the association with mortality risk, Yelak Biru, MSc, president and chief executive officer of the International Myeloma Foundation, said in an interview.

“This is a key area of study for addressing the disparities in treatments and outcomes that result in inequities,” said Mr. Biru, a patient advocate and multiple myeloma survivor who was not involved in the study.
 

What Does the New Study Show?

The new study characterized HRSNs in 5,855 adult cancer survivors aged 18-64 years and 5,918 aged 65-79 years. In the 18- to 64-year-old group, 25.5% reported moderate levels of HRSNs, and 18.3% reported severe HRSNs. In patients aged 65-79 years, 15.6% and 6.6% reported moderate HRSNs and severe HRSNs, respectively.

Severe HRSN was significantly associated with higher mortality risk in an adjusted analysis in patients aged 18-64 years (hazard ratio 2.00, P < .001).

Among adults aged 65-79 years, severe HRSN was not associated with higher mortality risk; however, in this older age group, those with 2-3 domains of medical financial hardship had significantly increased mortality risk compared with adults aged 65-79 years with zero domains of medical financial hardship (HR 1.58, P = .007).

Although the findings that HRSNs were associated with increased mortality risk, especially in the younger group, were not surprising, they serve as a call to action to address how HRSNs are contributing to cancer mortality, Mr. Biru said in an interview. “HRSNs, like food or housing insecurity, can lead to patients being unable to undergo the best treatment approach for their cancer,” he said.
 

What Are the Limitations and Research Gaps?

The study findings were limited by several factors including the use of self-reports to measure medical financial hardship, food insecurity, and nonmedical financial concerns in the NHIS, the researchers wrote in their discussion. More research with longer follow-up time beyond 1-5 years is needed, wrote Dr. Zheng and colleagues.

Studies also are needed to illustrate how patient navigation can help prevent patients from falling through the cracks with regard to social needs and financial hardships, Mr. Biru told this news organization.

Other areas for research include how addressing social needs affects health outcomes and whether programs designed to address social needs are effective, he said.

“Finally, qualitative research is needed to capture the lived experiences of cancer survivors facing these challenges. This knowledge can inform the development of more patient-centered interventions and policies that effectively address the social determinants of health and improve overall outcomes for all cancer survivors,” Mr. Biru said.
 

What Is the Takeaway Message for Clinicians?

HRSNs and financial hardship are significantly associated with increased risk of mortality in adult cancer survivors, Dr. Zheng and colleagues concluded. Looking ahead, comprehensive assessment of HRSNs and financial hardship may help clinicians connect patients with relevant services to mitigate the social and financial impacts of cancer, they wrote.

“The takeaway message for oncologists in practice is that addressing [HRSNs] and financial hardship is crucial for providing comprehensive and equitable cancer care,” Mr. Biru said during his interview.

“The impact of social determinants of health on cancer outcomes cannot be ignored, and oncologists play a vital role in identifying and addressing these needs,” he said. Sensitive, discussion-based screenings are needed to identify core needs such as food and transportation, but clinicians also can consider broader social factors and work with a team to connect patients to appropriate resources, he added.

“By recognizing the importance of HRSN screening and taking proactive steps to address these needs, oncologists can contribute to improving health outcomes, reducing healthcare disparities, and providing more equitable cancer care for their patients,” he said.
 

What Other Guidance Is Available?

“High-quality cancer care requires treating the whole person; measuring and addressing anything in their life that could result in poorer health outcomes is a key component of comprehensive care,” Mr. Biru emphasized.

In September 2023, the National Comprehensive Cancer Network (NCCN) convened a working group cochaired by Mr. Biru that developed recommendations for how oncology practices should routinely measure HRSNs (NCCN.org/social-needs).

“The working group proposed that every cancer patient be assessed for food, transportation access, and financial and housing security at least once a year, and be reassessed at every care transition point as well,” Mr. Biru said. Such screenings should include follow-up to connect patients with services to address any HRSNs they are experiencing, he added.

Lead author Dr. Zheng is employed by the American Cancer Society, which as a nonprofit receives funds from the public through fundraising and contributions, as well as some support from corporations and industry to support its mission programs and services. Mr. Biru had no financial conflicts to disclose.

Health-related social needs and medical financial hardship are associated with increased risk of mortality in adult cancer survivors, based on data from more than 10,000 individuals.

Little is known about the specific association between health-related social needs (HRSNs) and mortality risk even though HRSNs, defined as challenges in affording food, housing, and other necessities of daily living, are potential challenges for cancer survivors, wrote Zhiyuan Zheng, PhD, of the American Cancer Society, Atlanta, and colleagues.

A 2020 study by Dr. Zheng and colleagues published in the Journal of the National Comprehensive Cancer Network (NCCN) showed that food insecurity and financial worries had a negative impact on cancer survivorship. In the new study, published in Cancer, the researchers identified cancer survivors using the 2013-2018 National Health Interview Survey (NHIS) and the NHIS Mortality File through December 31, 2019. The researchers examined mortality using the data from the Centers for Disease Control and Prevention’s National Death Index (NDI) through December 31, 2019, which links to the National Health Interview Survey Data used in the study.

Individuals’ HRSNs were categorized into three groups: severe, moderate, and minor/none. HRSNs included food insecurity and nonmedical financial concerns, such as housing costs (rent, mortgage). Medical financial hardship included material, psychological, and behavioral domains and was divided into three groups: 2-3 domains, 1 domain, or 0 domains.
 

What Are the Potential Financial Implications of this Research?

The high costs of cancer care often cause medical financial hardships for cancer survivors, and expenses also may cause psychological distress and nonmedical financial hardship as survivors try to make ends meet while facing medical bills, wrote Dr. Zheng and colleagues.

Policy makers are increasingly interested in adding HRSNs to insurance coverage; recent guidance from the Centers for Medicare & Medicaid Services (CMS) allows individual states to apply to provide nutrition and housing supports through state Medicaid programs, according to authors of a 2023 article published in JAMA Health Forum.

The new study adds to the understanding of how HRSNs impact people with cancer by examining the association with mortality risk, Yelak Biru, MSc, president and chief executive officer of the International Myeloma Foundation, said in an interview.

“This is a key area of study for addressing the disparities in treatments and outcomes that result in inequities,” said Mr. Biru, a patient advocate and multiple myeloma survivor who was not involved in the study.
 

What Does the New Study Show?

The new study characterized HRSNs in 5,855 adult cancer survivors aged 18-64 years and 5,918 aged 65-79 years. In the 18- to 64-year-old group, 25.5% reported moderate levels of HRSNs, and 18.3% reported severe HRSNs. In patients aged 65-79 years, 15.6% and 6.6% reported moderate HRSNs and severe HRSNs, respectively.

Severe HRSN was significantly associated with higher mortality risk in an adjusted analysis in patients aged 18-64 years (hazard ratio 2.00, P < .001).

Among adults aged 65-79 years, severe HRSN was not associated with higher mortality risk; however, in this older age group, those with 2-3 domains of medical financial hardship had significantly increased mortality risk compared with adults aged 65-79 years with zero domains of medical financial hardship (HR 1.58, P = .007).

Although the findings that HRSNs were associated with increased mortality risk, especially in the younger group, were not surprising, they serve as a call to action to address how HRSNs are contributing to cancer mortality, Mr. Biru said in an interview. “HRSNs, like food or housing insecurity, can lead to patients being unable to undergo the best treatment approach for their cancer,” he said.
 

What Are the Limitations and Research Gaps?

The study findings were limited by several factors including the use of self-reports to measure medical financial hardship, food insecurity, and nonmedical financial concerns in the NHIS, the researchers wrote in their discussion. More research with longer follow-up time beyond 1-5 years is needed, wrote Dr. Zheng and colleagues.

Studies also are needed to illustrate how patient navigation can help prevent patients from falling through the cracks with regard to social needs and financial hardships, Mr. Biru told this news organization.

Other areas for research include how addressing social needs affects health outcomes and whether programs designed to address social needs are effective, he said.

“Finally, qualitative research is needed to capture the lived experiences of cancer survivors facing these challenges. This knowledge can inform the development of more patient-centered interventions and policies that effectively address the social determinants of health and improve overall outcomes for all cancer survivors,” Mr. Biru said.
 

What Is the Takeaway Message for Clinicians?

HRSNs and financial hardship are significantly associated with increased risk of mortality in adult cancer survivors, Dr. Zheng and colleagues concluded. Looking ahead, comprehensive assessment of HRSNs and financial hardship may help clinicians connect patients with relevant services to mitigate the social and financial impacts of cancer, they wrote.

“The takeaway message for oncologists in practice is that addressing [HRSNs] and financial hardship is crucial for providing comprehensive and equitable cancer care,” Mr. Biru said during his interview.

“The impact of social determinants of health on cancer outcomes cannot be ignored, and oncologists play a vital role in identifying and addressing these needs,” he said. Sensitive, discussion-based screenings are needed to identify core needs such as food and transportation, but clinicians also can consider broader social factors and work with a team to connect patients to appropriate resources, he added.

“By recognizing the importance of HRSN screening and taking proactive steps to address these needs, oncologists can contribute to improving health outcomes, reducing healthcare disparities, and providing more equitable cancer care for their patients,” he said.
 

What Other Guidance Is Available?

“High-quality cancer care requires treating the whole person; measuring and addressing anything in their life that could result in poorer health outcomes is a key component of comprehensive care,” Mr. Biru emphasized.

In September 2023, the National Comprehensive Cancer Network (NCCN) convened a working group cochaired by Mr. Biru that developed recommendations for how oncology practices should routinely measure HRSNs (NCCN.org/social-needs).

“The working group proposed that every cancer patient be assessed for food, transportation access, and financial and housing security at least once a year, and be reassessed at every care transition point as well,” Mr. Biru said. Such screenings should include follow-up to connect patients with services to address any HRSNs they are experiencing, he added.

Lead author Dr. Zheng is employed by the American Cancer Society, which as a nonprofit receives funds from the public through fundraising and contributions, as well as some support from corporations and industry to support its mission programs and services. Mr. Biru had no financial conflicts to disclose.

What’s most important to patients with terminal cancer and their caregivers?

New research found that patients and caregivers both tend to prioritize symptom control over life extension but often preferring a balance. Patients and caregivers, however, are less aligned on decisions about cost containment, with patients more likely to prioritize cost containment.

“Our research has revealed that patients and caregivers generally share similar end-of-life goals,” with a “notable exception” when it comes to costs, first author Semra Ozdemir, PhD, with the Lien Centre for Palliative Care, Duke-NUS Medical School, Singapore, told this news organization.

However, when patients and caregivers have a better understanding of the patient’s prognosis, both may be more inclined to avoid costly life-extending treatments and prioritize symptom management.

In other words, the survey suggests that “knowing the prognosis helps patients and their families set realistic expectations for care and adequately prepare for end-of-life decisions,” said Dr. Ozdemir.

This study was published online in JAMA Network Open.

Patients with advanced cancer often face difficult decisions: Do they opt for treatments that may — or may not — extend life or do they focus more on symptom control?

Family caregivers, who also play an important role in this decision-making process, may have different care goals. Some research suggests that caregivers tend to prioritize treatments that could extend life, whereas patients prioritize symptom management, but it’s less clear how these priorities may change over time and how patients and caregivers may influence each other.

In the current study, the researchers examined goals of care among patients with stage IV solid tumors and caregivers during the last 2 years of life, focusing on life extension vs symptom management and cost containment, as well as how these goals changed over time.

The survey included 210 patient-caregiver pairs, recruited from outpatient clinics at two major cancer centers in Singapore. Patients had a mean age of 63 years, and about half were men. The caregivers had a mean age of 49 years, and almost two third (63%) were women.

Overall, 34% patients and 29% caregivers prioritized symptom management over life extension, whereas 24% patients and 19% caregivers prioritized life extension. Most patients and caregivers preferred balancing the two, with 34%-47% patients and 37%-69% caregivers supporting this approach.

When balancing cost and treatment decisions, however, patients were more likely to prioritize containing costs — 28% vs 17% for caregivers — over extending life — 26% of patients vs 35% of caregivers.

Cost containment tended to be more of a priority for older patients, those with a higher symptom burden, and those with less family caregiver support. For caregivers, cost containment was more of a priority for those who reported that caregiving had a big impact on their finances, those with worse self-esteem related to their caregiving abilities, as well as those caring for older patients.

To better align cost containment priorities between patients and caregivers, it’s essential for families to engage in open and thorough discussions about the allocation of resources, Dr. Ozdemir said.

Although “patients, families, and physicians often avoid discussions about prognosis,” such conversations are essential for setting realistic expectations for care and adequately preparing for end-of-life decisions, Dr. Ozdemir told this news organization.

“These conversations should aim to balance competing interests and create care plans that are mutually acceptable to both patients and caregivers,” she said, adding that “this approach will help in minimizing any potential conflicts and ensure that both parties feel respected and understood in their decision-making process.”

Managing Unrealistic Expectations

As patients approached the end of life, neither patients nor caregivers shifted their priorities from life extension to symptom management.

This finding raises concerns because it suggests that many patients hold unrealistic expectations regarding their care and “underscores the need for continuous dialogue and reassessment of care goals throughout the progression of illness,” Dr. Ozdemir said.

“This stability in preferences over time suggests that initial care decisions are deeply ingrained or that there may be a lack of ongoing communication about evolving care needs and possibilities as conditions change,” Ozdemir said.

Yet, it can be hard to define what unrealistic expectations mean, said Olivia Seecof, MD, who wasn’t involved in the study.

“I think people are hopeful that a devastating diagnosis won’t lead to the end of their life and that there will be a treatment or something that will change [their prognosis], and they’ll get better,” said Dr. Seecof, palliative care expert with the Supportive Oncology Program at NYU Langone Health’s Perlmutter Cancer Center in New York City.

Giving patients and caregivers a realistic understanding of the prognosis is important, but “there’s more to it than just telling the patient their diagnosis,” she said.

“We have to plan for end of life, what it can look like,” said Dr. Seecof, adding that “often we don’t do a very good job of talking about that early on in an illness course.”

Overall, though, Dr. Seecof stressed that no two patients or situations are the same, and it’s important to understand what’s important in each scenario. End-of-life care requires “an individual approach because every patient is different, even if they have the same diagnosis as someone else,” she said.

This work was supported by funding from the Singapore Millennium Foundation and the Lien Centre for Palliative Care. Dr. Ozdemir and Dr. Seecof had no relevant disclosures.

A version of this article appeared on Medscape.com.

What’s most important to patients with terminal cancer and their caregivers?

New research found that patients and caregivers both tend to prioritize symptom control over life extension but often preferring a balance. Patients and caregivers, however, are less aligned on decisions about cost containment, with patients more likely to prioritize cost containment.

“Our research has revealed that patients and caregivers generally share similar end-of-life goals,” with a “notable exception” when it comes to costs, first author Semra Ozdemir, PhD, with the Lien Centre for Palliative Care, Duke-NUS Medical School, Singapore, told this news organization.

However, when patients and caregivers have a better understanding of the patient’s prognosis, both may be more inclined to avoid costly life-extending treatments and prioritize symptom management.

In other words, the survey suggests that “knowing the prognosis helps patients and their families set realistic expectations for care and adequately prepare for end-of-life decisions,” said Dr. Ozdemir.

This study was published online in JAMA Network Open.

Patients with advanced cancer often face difficult decisions: Do they opt for treatments that may — or may not — extend life or do they focus more on symptom control?

Family caregivers, who also play an important role in this decision-making process, may have different care goals. Some research suggests that caregivers tend to prioritize treatments that could extend life, whereas patients prioritize symptom management, but it’s less clear how these priorities may change over time and how patients and caregivers may influence each other.

In the current study, the researchers examined goals of care among patients with stage IV solid tumors and caregivers during the last 2 years of life, focusing on life extension vs symptom management and cost containment, as well as how these goals changed over time.

The survey included 210 patient-caregiver pairs, recruited from outpatient clinics at two major cancer centers in Singapore. Patients had a mean age of 63 years, and about half were men. The caregivers had a mean age of 49 years, and almost two third (63%) were women.

Overall, 34% patients and 29% caregivers prioritized symptom management over life extension, whereas 24% patients and 19% caregivers prioritized life extension. Most patients and caregivers preferred balancing the two, with 34%-47% patients and 37%-69% caregivers supporting this approach.

When balancing cost and treatment decisions, however, patients were more likely to prioritize containing costs — 28% vs 17% for caregivers — over extending life — 26% of patients vs 35% of caregivers.

Cost containment tended to be more of a priority for older patients, those with a higher symptom burden, and those with less family caregiver support. For caregivers, cost containment was more of a priority for those who reported that caregiving had a big impact on their finances, those with worse self-esteem related to their caregiving abilities, as well as those caring for older patients.

To better align cost containment priorities between patients and caregivers, it’s essential for families to engage in open and thorough discussions about the allocation of resources, Dr. Ozdemir said.

Although “patients, families, and physicians often avoid discussions about prognosis,” such conversations are essential for setting realistic expectations for care and adequately preparing for end-of-life decisions, Dr. Ozdemir told this news organization.

“These conversations should aim to balance competing interests and create care plans that are mutually acceptable to both patients and caregivers,” she said, adding that “this approach will help in minimizing any potential conflicts and ensure that both parties feel respected and understood in their decision-making process.”

Managing Unrealistic Expectations

As patients approached the end of life, neither patients nor caregivers shifted their priorities from life extension to symptom management.

This finding raises concerns because it suggests that many patients hold unrealistic expectations regarding their care and “underscores the need for continuous dialogue and reassessment of care goals throughout the progression of illness,” Dr. Ozdemir said.

“This stability in preferences over time suggests that initial care decisions are deeply ingrained or that there may be a lack of ongoing communication about evolving care needs and possibilities as conditions change,” Ozdemir said.

Yet, it can be hard to define what unrealistic expectations mean, said Olivia Seecof, MD, who wasn’t involved in the study.

“I think people are hopeful that a devastating diagnosis won’t lead to the end of their life and that there will be a treatment or something that will change [their prognosis], and they’ll get better,” said Dr. Seecof, palliative care expert with the Supportive Oncology Program at NYU Langone Health’s Perlmutter Cancer Center in New York City.

Giving patients and caregivers a realistic understanding of the prognosis is important, but “there’s more to it than just telling the patient their diagnosis,” she said.

“We have to plan for end of life, what it can look like,” said Dr. Seecof, adding that “often we don’t do a very good job of talking about that early on in an illness course.”

Overall, though, Dr. Seecof stressed that no two patients or situations are the same, and it’s important to understand what’s important in each scenario. End-of-life care requires “an individual approach because every patient is different, even if they have the same diagnosis as someone else,” she said.

This work was supported by funding from the Singapore Millennium Foundation and the Lien Centre for Palliative Care. Dr. Ozdemir and Dr. Seecof had no relevant disclosures.

A version of this article appeared on Medscape.com.

What’s most important to patients with terminal cancer and their caregivers?

New research found that patients and caregivers both tend to prioritize symptom control over life extension but often preferring a balance. Patients and caregivers, however, are less aligned on decisions about cost containment, with patients more likely to prioritize cost containment.

“Our research has revealed that patients and caregivers generally share similar end-of-life goals,” with a “notable exception” when it comes to costs, first author Semra Ozdemir, PhD, with the Lien Centre for Palliative Care, Duke-NUS Medical School, Singapore, told this news organization.

However, when patients and caregivers have a better understanding of the patient’s prognosis, both may be more inclined to avoid costly life-extending treatments and prioritize symptom management.

In other words, the survey suggests that “knowing the prognosis helps patients and their families set realistic expectations for care and adequately prepare for end-of-life decisions,” said Dr. Ozdemir.

This study was published online in JAMA Network Open.

Patients with advanced cancer often face difficult decisions: Do they opt for treatments that may — or may not — extend life or do they focus more on symptom control?

Family caregivers, who also play an important role in this decision-making process, may have different care goals. Some research suggests that caregivers tend to prioritize treatments that could extend life, whereas patients prioritize symptom management, but it’s less clear how these priorities may change over time and how patients and caregivers may influence each other.

In the current study, the researchers examined goals of care among patients with stage IV solid tumors and caregivers during the last 2 years of life, focusing on life extension vs symptom management and cost containment, as well as how these goals changed over time.

The survey included 210 patient-caregiver pairs, recruited from outpatient clinics at two major cancer centers in Singapore. Patients had a mean age of 63 years, and about half were men. The caregivers had a mean age of 49 years, and almost two third (63%) were women.

Overall, 34% patients and 29% caregivers prioritized symptom management over life extension, whereas 24% patients and 19% caregivers prioritized life extension. Most patients and caregivers preferred balancing the two, with 34%-47% patients and 37%-69% caregivers supporting this approach.

When balancing cost and treatment decisions, however, patients were more likely to prioritize containing costs — 28% vs 17% for caregivers — over extending life — 26% of patients vs 35% of caregivers.

Cost containment tended to be more of a priority for older patients, those with a higher symptom burden, and those with less family caregiver support. For caregivers, cost containment was more of a priority for those who reported that caregiving had a big impact on their finances, those with worse self-esteem related to their caregiving abilities, as well as those caring for older patients.

To better align cost containment priorities between patients and caregivers, it’s essential for families to engage in open and thorough discussions about the allocation of resources, Dr. Ozdemir said.

Although “patients, families, and physicians often avoid discussions about prognosis,” such conversations are essential for setting realistic expectations for care and adequately preparing for end-of-life decisions, Dr. Ozdemir told this news organization.

“These conversations should aim to balance competing interests and create care plans that are mutually acceptable to both patients and caregivers,” she said, adding that “this approach will help in minimizing any potential conflicts and ensure that both parties feel respected and understood in their decision-making process.”

Managing Unrealistic Expectations

As patients approached the end of life, neither patients nor caregivers shifted their priorities from life extension to symptom management.

This finding raises concerns because it suggests that many patients hold unrealistic expectations regarding their care and “underscores the need for continuous dialogue and reassessment of care goals throughout the progression of illness,” Dr. Ozdemir said.

“This stability in preferences over time suggests that initial care decisions are deeply ingrained or that there may be a lack of ongoing communication about evolving care needs and possibilities as conditions change,” Ozdemir said.

Yet, it can be hard to define what unrealistic expectations mean, said Olivia Seecof, MD, who wasn’t involved in the study.

“I think people are hopeful that a devastating diagnosis won’t lead to the end of their life and that there will be a treatment or something that will change [their prognosis], and they’ll get better,” said Dr. Seecof, palliative care expert with the Supportive Oncology Program at NYU Langone Health’s Perlmutter Cancer Center in New York City.

Giving patients and caregivers a realistic understanding of the prognosis is important, but “there’s more to it than just telling the patient their diagnosis,” she said.

“We have to plan for end of life, what it can look like,” said Dr. Seecof, adding that “often we don’t do a very good job of talking about that early on in an illness course.”

Overall, though, Dr. Seecof stressed that no two patients or situations are the same, and it’s important to understand what’s important in each scenario. End-of-life care requires “an individual approach because every patient is different, even if they have the same diagnosis as someone else,” she said.

This work was supported by funding from the Singapore Millennium Foundation and the Lien Centre for Palliative Care. Dr. Ozdemir and Dr. Seecof had no relevant disclosures.

A version of this article appeared on Medscape.com.

A contentious scientific debate is clouding prospects for a deeper understanding of the microbiome’s role in cancer, a relatively young field of research that some believe could lead to breakthroughs in the diagnosis and treatment of the second-leading cause of death in the United States. 

Last year, the controversy heightened when experts questioned a high-profile study — a 2020 analysis claiming that the tumors of 33 different cancers had their own unique microbiomes — on whether the “signature” of these bacterial compositions could help diagnose cancer.

The incident renewed the spotlight on “tumor microbiomes” because of the bold claims of the original paper and the strongly worded refutations of those claims. The broader field has focused primarily on ways the body’s microbiome interacts with cancers and cancer treatment.

This controversy has highlighted the challenges of making headway in a field where researchers may not even have the tools yet to puzzle-out the wide-ranging implications the microbiome holds for cancer diagnosis and treatment.

But it is also part of a provocative question within that larger field: whether tumors in the body, far from the natural microbiome in the gut, have their own thriving communities of bacteria, viruses, and fungi. And, if they do, how do those tumor microbiomes affect the development and progression of the cancer and the effectiveness of cancer therapies? 
 

Cancer Controversy

The evidence is undeniable that some microbes can directly cause certain cancers and that the human gut microbiome can influence the effectiveness of certain therapies. Beyond that established science, however, the research has raised as many questions as answers about what we do and don’t know about microbiota and cancer.

The only confirmed microbiomes are on the skin and in the gut, mouth, and vagina, which are all areas with an easy direct route for bacteria to enter and grow in or on the body. A series of papers in recent years have suggested that other internal organs, and tumors within them, may have their own microbiomes. 

“Whether microbes exist in tumors of internal organs beyond body surfaces exposed to the environment is a different matter,” said Ivan Vujkovic-Cvijin, PhD, an assistant professor of biomedical sciences and gastroenterology at Cedars-Sinai Medical Center in Los Angeles, whose lab studies how human gut microbes affect inflammatory diseases. “We’ve only recently had the tools to study that question on a molecular level, and the reported results have been conflicting.” 

For example, research allegedly identified microbiota in the human placenta nearly one decade ago. But subsequent research contradicted those claims and showed that the source of the “placental microbiome” was actually contamination. Subsequent similar studies for other parts of the body faced the same scrutiny and, often, eventual debunking.

“Most likely, our immune system has undergone selective pressure to eliminate everything that crosses the gut barrier because there’s not much benefit to the body to have bacteria run amok in our internal organs,” Dr. Vujkovic-Cvijin said. “That can only disrupt the functioning of our tissues, to have an external organism living inside them.” 

The controversy that erupted last summer, surrounding research from the lab of Rob Knight, PhD, at the University of California, San Diego, centered on a slightly different but related question: Could tumors harbor their own microbiomes?

This news organization spoke with two of the authors who published a paper contesting Dr. Knight’s findings: Steven Salzberg, PhD, a professor of biomedical engineering at John Hopkins Medicine, Baltimore, Maryland, and Abraham Gihawi, PhD, a research fellow at Norwich Medical School at the University of East Anglia in the United Kingdom. 

Dr. Salzberg described two major problems with Dr. Knight’s study. 

“What they found were false positives because of contamination in the database and flaws in their methods,” Dr. Salzberg said. “I can’t prove there’s no cancer microbiome, but I can say the cancer microbiomes that they reported don’t exist because the species they were finding aren’t there.”

Dr. Knight disagrees with Dr. Salzberg’s findings, noting that Dr. Salzberg and his co-authors did not examine the publicly available databases used in his study. In a written response, he said that his team’s examination of the database revealed that less than 1% of the microbial genomes overlapped with human ones and that removing them did not change their findings.

Dr. Knight also noted that his team could still “distinguish cancer types by their microbiome” even after running their analysis without the technique that Dr. Salzberg found fault with.

Dr. Salzberg said that the database linked above is not the one Dr. Knight’s study used, however. “The primary database in their study was never made public (it’s too large, they said), and it has/had about 69,000 genomes,” Dr. Salzberg said by email. “But even if we did, this is irrelevant. He’s trying to distract from the primary errors in their study,” which Dr. Salzberg said Dr. Knight’s team has not addressed. 

The critiques Dr. Salzberg raised have been leveled at other studies investigating microbiomes specifically within tumors and independent of the body’s microbiome.

For example, a 2019 study in Nature described a fungal microbiome in pancreatic cancer that a Nature paper 4 years later directly contradicted, citing flaws that invalidated the original findings. A different 2019 study in Cell examined pancreatic tumor microbiota and patient outcomes, but it’s unclear whether the microorganisms moved from the gut to the pancreas or “constitute a durably colonized community that lives inside the tumor,” which remains a matter of debate, Dr. Vujkovic-Cvijin said.

A 2020 study in Science suggested diverse microbial communities in seven tumor types, but those findings were similarly called into question. That study stated that “bacteria were first detected in human tumors more than 100 years ago” and that “bacteria are well-known residents in human tumors,” but Dr. Salzberg considers those statements misleading. 

It’s true that bacteria and viruses have been detected in tumors because “there’s very good evidence that an acute infection caused by a very small number of viruses and bacteria can cause a tumor,” Dr. Salzberg said. Human papillomavirus, for example, can cause six different types of cancer. Inflammation and ulcers caused by Helicobacter pylori may progress to stomach cancer, and Fusobacterium nucleatum and Enterococcus faecalis have been shown to contribute to colorectal cancer. Those examples differ from a microbiome; this “a community of bacteria and possibly other microscopic bugs, like fungi, that are happily living in the tumor” the same way microbes reside in our guts, he said.

Dr. Knight said that many bacteria his team identified “have been confirmed independently in subsequent work.” He acknowledged, however, that more research is needed. 

Several of the contested studies above were among a lengthy list that Dr. Knight provided, noting that most of the disagreements “have two sides to them, and critiques from one particular group does not immediately invalidate a reported finding.” 

Yet, many of the papers Dr. Knight listed are precisely the types that skeptics like Dr. Salzberg believe are too flawed to draw reliable conclusions. 

“I think many agree that microbes may exist within tumors that are exposed to the environment, like tumors of the skin, gut, and mouth,” Dr. Vujkovic-Cvijin said. It’s less clear, however, whether tumors further from the body’s microbiome harbor any microbes or where they came from if they do. Microbial signals in organs elsewhere in the body become faint quickly, he said.
 

Underdeveloped Technology 

Though Dr. Salzberg said that the concept of a tumor microbiome is “implausible” because there’s no easy route for bacteria to reach internal organs, it’s unclear whether scientists have the technology yet to adequately answer this question. 

For one thing, samples in these types of studies are typically “ultra-low biomass samples, where the signal — the amount of microbes in the sample — is so low that it’s comparable to how much would be expected to be found in reagents and environmental contamination through processing,” Dr. Vujkovic-Cvijin explained. Many polymerases used to amplify a DNA signal, for example, are made in bacteria and may retain trace amounts identified in these studies. 

Dr. Knight agreed that low biomass is a challenge in this field but is not an unsurmountable one. 

Another challenge is that study samples, as with Dr. Knight’s work, were collected during routine surgeries without the intent to find a microbial signal. Simply using a scalpel to cut through the skin means cutting through a layer of bacteria, and surgery rooms are not designed to eliminate all bacteria. Some work has even shown there is a “hospital microbiome,” so “you can easily have that creep into your signal and mistake it for tumor-resident bacteria,” Dr. Vujkovic-Cvijin said. 

Dr. Knight asserted that the samples are taken under sterile conditions, but other researchers do not think the level of sterility necessary for completely clean samples is possible. 

“Just because it’s in your sample doesn’t mean it was in your tumor,” Dr. Gihawi said.

Even if scientists can retrieve a reliable sample without contamination, analyzing it requires comparing the genetic material to existing databases of microbial genomes. Yet, contamination and misclassification of genetic sequences can be problems in those reference genomes too, Dr. Gihawi explained.

Machine learning algorithms have a role in interpreting data, but “we need to be careful of what we use them for,” he added.

“These techniques are in their infancy, and we’re starting to chase them down, which is why we need to move microbiome research in a way that can be used clinically,” Dr. Gihawi said. 
 

Influence on Cancer Treatment Outcomes

Again, however, the question of whether microbiomes exist within tumors is only one slice of the much larger field looking at microbiomes and cancer, including its influence on cancer treatment outcomes. Although much remains to be learned, less controversy exists over the thousands of studies in the past two decades that have gradually revealed how the body’s microbiome can affect both the course of a cancer and the effectiveness of different treatments.

The growing research showing the importance of the gut microbiome in cancer treatments is not surprising given its role in immunity more broadly. Because the human immune system must recognize and defend against microbes, the microbiome helps train it, Dr. Vujkovic-Cvijin said. 

Some bacteria can escape the gut — a phenomenon called bacterial translocation — and may aid in fighting tumors. To grow large enough to be seen on imaging, tumors need to evolve several abilities, such as growing enough vascularization to receive blood flow and shutting down local immune responses.

“Any added boost, like immunotherapy, has a chance of breaking through that immune forcefield and killing the tumor cells,” Dr. Vujkovic-Cvijin said. Escaped gut bacteria may provide that boost. 

“There’s a lot of evidence that depletion of the gut microbiome impairs immunotherapy and chemotherapy. The thinking behind some of those studies is that gut microbes can cross the gut barrier and when they do, they activate the immune system,” he said. 

In mice engineered to have sterile guts, for example, the lack of bacteria results in less effective immune systems, Dr. Vujkovic-Cvijin pointed out. A host of research has shown that antibiotic exposure during and even 6 months before immunotherapy dramatically reduces survival rates. “That’s pretty convincing to me that gut microbes are important,” he said. 

Dr. Vujkovic-Cvijin cautioned that there continues to be controversy on understanding which bacteria are important for response to immunotherapy. “The field is still in its infancy in terms of understanding which bacteria are most important for these effects,” he said.

Dr. Knight suggested that escaped bacteria may be the genesis of the ones that he and other researchers believe exist in tumors. “Because tumor microbes must come from somewhere, it is to be expected that some of those microbes will be co-opted from body-site specific commensals.”

It’s also possible that metabolites released from gut bacteria escape the gut and could theoretically affect distant tumor growth, Dr. Gihawi said. The most promising avenue of research in this area is metabolites being used as biomarkers, added Dr. Gihawi, whose lab published research on a link between bacteria detected in men’s urine and a more aggressive subset of prostate cancers. But that research is not far enough along to develop lab tests for clinical use, he noted. 
 

No Consensus Yet

Even before the controversy erupted around Dr. Knight’s research, he co-founded the company Micronoma to develop cancer tests based on his microbe findings. The company has raised $17.5 million from private investors as of August 2023 and received the US Food and Drug Administration’s Breakthrough Device designation, allowing the firm to fast-track clinical trials testing the technology. The recent critiques have not changed the company’s plans. 

It’s safe to say that scientists will continue to research and debate the possibility of tumor microbiomes until a consensus emerges. 

“The field is evolving and studies testing the reproducibility of tumor-resident microbial signals are essential for developing our understanding in this area,” Dr. Vujkovic-Cvijin said.

Even if that path ultimately leads nowhere, as Dr. Salzberg expects, research into microbiomes and cancer has plenty of other directions to go.

“I’m actually quite an optimist,” Dr. Gihawi said. “I think there’s a lot of scope for some really good research here, especially in the sites where we know there is a strong microbiome, such as the gastrointestinal tract.”

A version of this article appeared on Medscape.com.

A contentious scientific debate is clouding prospects for a deeper understanding of the microbiome’s role in cancer, a relatively young field of research that some believe could lead to breakthroughs in the diagnosis and treatment of the second-leading cause of death in the United States. 

Last year, the controversy heightened when experts questioned a high-profile study — a 2020 analysis claiming that the tumors of 33 different cancers had their own unique microbiomes — on whether the “signature” of these bacterial compositions could help diagnose cancer.

The incident renewed the spotlight on “tumor microbiomes” because of the bold claims of the original paper and the strongly worded refutations of those claims. The broader field has focused primarily on ways the body’s microbiome interacts with cancers and cancer treatment.

This controversy has highlighted the challenges of making headway in a field where researchers may not even have the tools yet to puzzle-out the wide-ranging implications the microbiome holds for cancer diagnosis and treatment.

But it is also part of a provocative question within that larger field: whether tumors in the body, far from the natural microbiome in the gut, have their own thriving communities of bacteria, viruses, and fungi. And, if they do, how do those tumor microbiomes affect the development and progression of the cancer and the effectiveness of cancer therapies? 
 

Cancer Controversy

The evidence is undeniable that some microbes can directly cause certain cancers and that the human gut microbiome can influence the effectiveness of certain therapies. Beyond that established science, however, the research has raised as many questions as answers about what we do and don’t know about microbiota and cancer.

The only confirmed microbiomes are on the skin and in the gut, mouth, and vagina, which are all areas with an easy direct route for bacteria to enter and grow in or on the body. A series of papers in recent years have suggested that other internal organs, and tumors within them, may have their own microbiomes. 

“Whether microbes exist in tumors of internal organs beyond body surfaces exposed to the environment is a different matter,” said Ivan Vujkovic-Cvijin, PhD, an assistant professor of biomedical sciences and gastroenterology at Cedars-Sinai Medical Center in Los Angeles, whose lab studies how human gut microbes affect inflammatory diseases. “We’ve only recently had the tools to study that question on a molecular level, and the reported results have been conflicting.” 

For example, research allegedly identified microbiota in the human placenta nearly one decade ago. But subsequent research contradicted those claims and showed that the source of the “placental microbiome” was actually contamination. Subsequent similar studies for other parts of the body faced the same scrutiny and, often, eventual debunking.

“Most likely, our immune system has undergone selective pressure to eliminate everything that crosses the gut barrier because there’s not much benefit to the body to have bacteria run amok in our internal organs,” Dr. Vujkovic-Cvijin said. “That can only disrupt the functioning of our tissues, to have an external organism living inside them.” 

The controversy that erupted last summer, surrounding research from the lab of Rob Knight, PhD, at the University of California, San Diego, centered on a slightly different but related question: Could tumors harbor their own microbiomes?

This news organization spoke with two of the authors who published a paper contesting Dr. Knight’s findings: Steven Salzberg, PhD, a professor of biomedical engineering at John Hopkins Medicine, Baltimore, Maryland, and Abraham Gihawi, PhD, a research fellow at Norwich Medical School at the University of East Anglia in the United Kingdom. 

Dr. Salzberg described two major problems with Dr. Knight’s study. 

“What they found were false positives because of contamination in the database and flaws in their methods,” Dr. Salzberg said. “I can’t prove there’s no cancer microbiome, but I can say the cancer microbiomes that they reported don’t exist because the species they were finding aren’t there.”

Dr. Knight disagrees with Dr. Salzberg’s findings, noting that Dr. Salzberg and his co-authors did not examine the publicly available databases used in his study. In a written response, he said that his team’s examination of the database revealed that less than 1% of the microbial genomes overlapped with human ones and that removing them did not change their findings.

Dr. Knight also noted that his team could still “distinguish cancer types by their microbiome” even after running their analysis without the technique that Dr. Salzberg found fault with.

Dr. Salzberg said that the database linked above is not the one Dr. Knight’s study used, however. “The primary database in their study was never made public (it’s too large, they said), and it has/had about 69,000 genomes,” Dr. Salzberg said by email. “But even if we did, this is irrelevant. He’s trying to distract from the primary errors in their study,” which Dr. Salzberg said Dr. Knight’s team has not addressed. 

The critiques Dr. Salzberg raised have been leveled at other studies investigating microbiomes specifically within tumors and independent of the body’s microbiome.

For example, a 2019 study in Nature described a fungal microbiome in pancreatic cancer that a Nature paper 4 years later directly contradicted, citing flaws that invalidated the original findings. A different 2019 study in Cell examined pancreatic tumor microbiota and patient outcomes, but it’s unclear whether the microorganisms moved from the gut to the pancreas or “constitute a durably colonized community that lives inside the tumor,” which remains a matter of debate, Dr. Vujkovic-Cvijin said.

A 2020 study in Science suggested diverse microbial communities in seven tumor types, but those findings were similarly called into question. That study stated that “bacteria were first detected in human tumors more than 100 years ago” and that “bacteria are well-known residents in human tumors,” but Dr. Salzberg considers those statements misleading. 

It’s true that bacteria and viruses have been detected in tumors because “there’s very good evidence that an acute infection caused by a very small number of viruses and bacteria can cause a tumor,” Dr. Salzberg said. Human papillomavirus, for example, can cause six different types of cancer. Inflammation and ulcers caused by Helicobacter pylori may progress to stomach cancer, and Fusobacterium nucleatum and Enterococcus faecalis have been shown to contribute to colorectal cancer. Those examples differ from a microbiome; this “a community of bacteria and possibly other microscopic bugs, like fungi, that are happily living in the tumor” the same way microbes reside in our guts, he said.

Dr. Knight said that many bacteria his team identified “have been confirmed independently in subsequent work.” He acknowledged, however, that more research is needed. 

Several of the contested studies above were among a lengthy list that Dr. Knight provided, noting that most of the disagreements “have two sides to them, and critiques from one particular group does not immediately invalidate a reported finding.” 

Yet, many of the papers Dr. Knight listed are precisely the types that skeptics like Dr. Salzberg believe are too flawed to draw reliable conclusions. 

“I think many agree that microbes may exist within tumors that are exposed to the environment, like tumors of the skin, gut, and mouth,” Dr. Vujkovic-Cvijin said. It’s less clear, however, whether tumors further from the body’s microbiome harbor any microbes or where they came from if they do. Microbial signals in organs elsewhere in the body become faint quickly, he said.
 

Underdeveloped Technology 

Though Dr. Salzberg said that the concept of a tumor microbiome is “implausible” because there’s no easy route for bacteria to reach internal organs, it’s unclear whether scientists have the technology yet to adequately answer this question. 

For one thing, samples in these types of studies are typically “ultra-low biomass samples, where the signal — the amount of microbes in the sample — is so low that it’s comparable to how much would be expected to be found in reagents and environmental contamination through processing,” Dr. Vujkovic-Cvijin explained. Many polymerases used to amplify a DNA signal, for example, are made in bacteria and may retain trace amounts identified in these studies. 

Dr. Knight agreed that low biomass is a challenge in this field but is not an unsurmountable one. 

Another challenge is that study samples, as with Dr. Knight’s work, were collected during routine surgeries without the intent to find a microbial signal. Simply using a scalpel to cut through the skin means cutting through a layer of bacteria, and surgery rooms are not designed to eliminate all bacteria. Some work has even shown there is a “hospital microbiome,” so “you can easily have that creep into your signal and mistake it for tumor-resident bacteria,” Dr. Vujkovic-Cvijin said. 

Dr. Knight asserted that the samples are taken under sterile conditions, but other researchers do not think the level of sterility necessary for completely clean samples is possible. 

“Just because it’s in your sample doesn’t mean it was in your tumor,” Dr. Gihawi said.

Even if scientists can retrieve a reliable sample without contamination, analyzing it requires comparing the genetic material to existing databases of microbial genomes. Yet, contamination and misclassification of genetic sequences can be problems in those reference genomes too, Dr. Gihawi explained.

Machine learning algorithms have a role in interpreting data, but “we need to be careful of what we use them for,” he added.

“These techniques are in their infancy, and we’re starting to chase them down, which is why we need to move microbiome research in a way that can be used clinically,” Dr. Gihawi said. 
 

Influence on Cancer Treatment Outcomes

Again, however, the question of whether microbiomes exist within tumors is only one slice of the much larger field looking at microbiomes and cancer, including its influence on cancer treatment outcomes. Although much remains to be learned, less controversy exists over the thousands of studies in the past two decades that have gradually revealed how the body’s microbiome can affect both the course of a cancer and the effectiveness of different treatments.

The growing research showing the importance of the gut microbiome in cancer treatments is not surprising given its role in immunity more broadly. Because the human immune system must recognize and defend against microbes, the microbiome helps train it, Dr. Vujkovic-Cvijin said. 

Some bacteria can escape the gut — a phenomenon called bacterial translocation — and may aid in fighting tumors. To grow large enough to be seen on imaging, tumors need to evolve several abilities, such as growing enough vascularization to receive blood flow and shutting down local immune responses.

“Any added boost, like immunotherapy, has a chance of breaking through that immune forcefield and killing the tumor cells,” Dr. Vujkovic-Cvijin said. Escaped gut bacteria may provide that boost. 

“There’s a lot of evidence that depletion of the gut microbiome impairs immunotherapy and chemotherapy. The thinking behind some of those studies is that gut microbes can cross the gut barrier and when they do, they activate the immune system,” he said. 

In mice engineered to have sterile guts, for example, the lack of bacteria results in less effective immune systems, Dr. Vujkovic-Cvijin pointed out. A host of research has shown that antibiotic exposure during and even 6 months before immunotherapy dramatically reduces survival rates. “That’s pretty convincing to me that gut microbes are important,” he said. 

Dr. Vujkovic-Cvijin cautioned that there continues to be controversy on understanding which bacteria are important for response to immunotherapy. “The field is still in its infancy in terms of understanding which bacteria are most important for these effects,” he said.

Dr. Knight suggested that escaped bacteria may be the genesis of the ones that he and other researchers believe exist in tumors. “Because tumor microbes must come from somewhere, it is to be expected that some of those microbes will be co-opted from body-site specific commensals.”

It’s also possible that metabolites released from gut bacteria escape the gut and could theoretically affect distant tumor growth, Dr. Gihawi said. The most promising avenue of research in this area is metabolites being used as biomarkers, added Dr. Gihawi, whose lab published research on a link between bacteria detected in men’s urine and a more aggressive subset of prostate cancers. But that research is not far enough along to develop lab tests for clinical use, he noted. 
 

No Consensus Yet

Even before the controversy erupted around Dr. Knight’s research, he co-founded the company Micronoma to develop cancer tests based on his microbe findings. The company has raised $17.5 million from private investors as of August 2023 and received the US Food and Drug Administration’s Breakthrough Device designation, allowing the firm to fast-track clinical trials testing the technology. The recent critiques have not changed the company’s plans. 

It’s safe to say that scientists will continue to research and debate the possibility of tumor microbiomes until a consensus emerges. 

“The field is evolving and studies testing the reproducibility of tumor-resident microbial signals are essential for developing our understanding in this area,” Dr. Vujkovic-Cvijin said.

Even if that path ultimately leads nowhere, as Dr. Salzberg expects, research into microbiomes and cancer has plenty of other directions to go.

“I’m actually quite an optimist,” Dr. Gihawi said. “I think there’s a lot of scope for some really good research here, especially in the sites where we know there is a strong microbiome, such as the gastrointestinal tract.”

A version of this article appeared on Medscape.com.

A contentious scientific debate is clouding prospects for a deeper understanding of the microbiome’s role in cancer, a relatively young field of research that some believe could lead to breakthroughs in the diagnosis and treatment of the second-leading cause of death in the United States. 

Last year, the controversy heightened when experts questioned a high-profile study — a 2020 analysis claiming that the tumors of 33 different cancers had their own unique microbiomes — on whether the “signature” of these bacterial compositions could help diagnose cancer.

The incident renewed the spotlight on “tumor microbiomes” because of the bold claims of the original paper and the strongly worded refutations of those claims. The broader field has focused primarily on ways the body’s microbiome interacts with cancers and cancer treatment.

This controversy has highlighted the challenges of making headway in a field where researchers may not even have the tools yet to puzzle-out the wide-ranging implications the microbiome holds for cancer diagnosis and treatment.

But it is also part of a provocative question within that larger field: whether tumors in the body, far from the natural microbiome in the gut, have their own thriving communities of bacteria, viruses, and fungi. And, if they do, how do those tumor microbiomes affect the development and progression of the cancer and the effectiveness of cancer therapies? 
 

Cancer Controversy

The evidence is undeniable that some microbes can directly cause certain cancers and that the human gut microbiome can influence the effectiveness of certain therapies. Beyond that established science, however, the research has raised as many questions as answers about what we do and don’t know about microbiota and cancer.

The only confirmed microbiomes are on the skin and in the gut, mouth, and vagina, which are all areas with an easy direct route for bacteria to enter and grow in or on the body. A series of papers in recent years have suggested that other internal organs, and tumors within them, may have their own microbiomes. 

“Whether microbes exist in tumors of internal organs beyond body surfaces exposed to the environment is a different matter,” said Ivan Vujkovic-Cvijin, PhD, an assistant professor of biomedical sciences and gastroenterology at Cedars-Sinai Medical Center in Los Angeles, whose lab studies how human gut microbes affect inflammatory diseases. “We’ve only recently had the tools to study that question on a molecular level, and the reported results have been conflicting.” 

For example, research allegedly identified microbiota in the human placenta nearly one decade ago. But subsequent research contradicted those claims and showed that the source of the “placental microbiome” was actually contamination. Subsequent similar studies for other parts of the body faced the same scrutiny and, often, eventual debunking.

“Most likely, our immune system has undergone selective pressure to eliminate everything that crosses the gut barrier because there’s not much benefit to the body to have bacteria run amok in our internal organs,” Dr. Vujkovic-Cvijin said. “That can only disrupt the functioning of our tissues, to have an external organism living inside them.” 

The controversy that erupted last summer, surrounding research from the lab of Rob Knight, PhD, at the University of California, San Diego, centered on a slightly different but related question: Could tumors harbor their own microbiomes?

This news organization spoke with two of the authors who published a paper contesting Dr. Knight’s findings: Steven Salzberg, PhD, a professor of biomedical engineering at John Hopkins Medicine, Baltimore, Maryland, and Abraham Gihawi, PhD, a research fellow at Norwich Medical School at the University of East Anglia in the United Kingdom. 

Dr. Salzberg described two major problems with Dr. Knight’s study. 

“What they found were false positives because of contamination in the database and flaws in their methods,” Dr. Salzberg said. “I can’t prove there’s no cancer microbiome, but I can say the cancer microbiomes that they reported don’t exist because the species they were finding aren’t there.”

Dr. Knight disagrees with Dr. Salzberg’s findings, noting that Dr. Salzberg and his co-authors did not examine the publicly available databases used in his study. In a written response, he said that his team’s examination of the database revealed that less than 1% of the microbial genomes overlapped with human ones and that removing them did not change their findings.

Dr. Knight also noted that his team could still “distinguish cancer types by their microbiome” even after running their analysis without the technique that Dr. Salzberg found fault with.

Dr. Salzberg said that the database linked above is not the one Dr. Knight’s study used, however. “The primary database in their study was never made public (it’s too large, they said), and it has/had about 69,000 genomes,” Dr. Salzberg said by email. “But even if we did, this is irrelevant. He’s trying to distract from the primary errors in their study,” which Dr. Salzberg said Dr. Knight’s team has not addressed. 

The critiques Dr. Salzberg raised have been leveled at other studies investigating microbiomes specifically within tumors and independent of the body’s microbiome.

For example, a 2019 study in Nature described a fungal microbiome in pancreatic cancer that a Nature paper 4 years later directly contradicted, citing flaws that invalidated the original findings. A different 2019 study in Cell examined pancreatic tumor microbiota and patient outcomes, but it’s unclear whether the microorganisms moved from the gut to the pancreas or “constitute a durably colonized community that lives inside the tumor,” which remains a matter of debate, Dr. Vujkovic-Cvijin said.

A 2020 study in Science suggested diverse microbial communities in seven tumor types, but those findings were similarly called into question. That study stated that “bacteria were first detected in human tumors more than 100 years ago” and that “bacteria are well-known residents in human tumors,” but Dr. Salzberg considers those statements misleading. 

It’s true that bacteria and viruses have been detected in tumors because “there’s very good evidence that an acute infection caused by a very small number of viruses and bacteria can cause a tumor,” Dr. Salzberg said. Human papillomavirus, for example, can cause six different types of cancer. Inflammation and ulcers caused by Helicobacter pylori may progress to stomach cancer, and Fusobacterium nucleatum and Enterococcus faecalis have been shown to contribute to colorectal cancer. Those examples differ from a microbiome; this “a community of bacteria and possibly other microscopic bugs, like fungi, that are happily living in the tumor” the same way microbes reside in our guts, he said.

Dr. Knight said that many bacteria his team identified “have been confirmed independently in subsequent work.” He acknowledged, however, that more research is needed. 

Several of the contested studies above were among a lengthy list that Dr. Knight provided, noting that most of the disagreements “have two sides to them, and critiques from one particular group does not immediately invalidate a reported finding.” 

Yet, many of the papers Dr. Knight listed are precisely the types that skeptics like Dr. Salzberg believe are too flawed to draw reliable conclusions. 

“I think many agree that microbes may exist within tumors that are exposed to the environment, like tumors of the skin, gut, and mouth,” Dr. Vujkovic-Cvijin said. It’s less clear, however, whether tumors further from the body’s microbiome harbor any microbes or where they came from if they do. Microbial signals in organs elsewhere in the body become faint quickly, he said.
 

Underdeveloped Technology 

Though Dr. Salzberg said that the concept of a tumor microbiome is “implausible” because there’s no easy route for bacteria to reach internal organs, it’s unclear whether scientists have the technology yet to adequately answer this question. 

For one thing, samples in these types of studies are typically “ultra-low biomass samples, where the signal — the amount of microbes in the sample — is so low that it’s comparable to how much would be expected to be found in reagents and environmental contamination through processing,” Dr. Vujkovic-Cvijin explained. Many polymerases used to amplify a DNA signal, for example, are made in bacteria and may retain trace amounts identified in these studies. 

Dr. Knight agreed that low biomass is a challenge in this field but is not an unsurmountable one. 

Another challenge is that study samples, as with Dr. Knight’s work, were collected during routine surgeries without the intent to find a microbial signal. Simply using a scalpel to cut through the skin means cutting through a layer of bacteria, and surgery rooms are not designed to eliminate all bacteria. Some work has even shown there is a “hospital microbiome,” so “you can easily have that creep into your signal and mistake it for tumor-resident bacteria,” Dr. Vujkovic-Cvijin said. 

Dr. Knight asserted that the samples are taken under sterile conditions, but other researchers do not think the level of sterility necessary for completely clean samples is possible. 

“Just because it’s in your sample doesn’t mean it was in your tumor,” Dr. Gihawi said.

Even if scientists can retrieve a reliable sample without contamination, analyzing it requires comparing the genetic material to existing databases of microbial genomes. Yet, contamination and misclassification of genetic sequences can be problems in those reference genomes too, Dr. Gihawi explained.

Machine learning algorithms have a role in interpreting data, but “we need to be careful of what we use them for,” he added.

“These techniques are in their infancy, and we’re starting to chase them down, which is why we need to move microbiome research in a way that can be used clinically,” Dr. Gihawi said. 
 

Influence on Cancer Treatment Outcomes

Again, however, the question of whether microbiomes exist within tumors is only one slice of the much larger field looking at microbiomes and cancer, including its influence on cancer treatment outcomes. Although much remains to be learned, less controversy exists over the thousands of studies in the past two decades that have gradually revealed how the body’s microbiome can affect both the course of a cancer and the effectiveness of different treatments.

The growing research showing the importance of the gut microbiome in cancer treatments is not surprising given its role in immunity more broadly. Because the human immune system must recognize and defend against microbes, the microbiome helps train it, Dr. Vujkovic-Cvijin said. 

Some bacteria can escape the gut — a phenomenon called bacterial translocation — and may aid in fighting tumors. To grow large enough to be seen on imaging, tumors need to evolve several abilities, such as growing enough vascularization to receive blood flow and shutting down local immune responses.

“Any added boost, like immunotherapy, has a chance of breaking through that immune forcefield and killing the tumor cells,” Dr. Vujkovic-Cvijin said. Escaped gut bacteria may provide that boost. 

“There’s a lot of evidence that depletion of the gut microbiome impairs immunotherapy and chemotherapy. The thinking behind some of those studies is that gut microbes can cross the gut barrier and when they do, they activate the immune system,” he said. 

In mice engineered to have sterile guts, for example, the lack of bacteria results in less effective immune systems, Dr. Vujkovic-Cvijin pointed out. A host of research has shown that antibiotic exposure during and even 6 months before immunotherapy dramatically reduces survival rates. “That’s pretty convincing to me that gut microbes are important,” he said. 

Dr. Vujkovic-Cvijin cautioned that there continues to be controversy on understanding which bacteria are important for response to immunotherapy. “The field is still in its infancy in terms of understanding which bacteria are most important for these effects,” he said.

Dr. Knight suggested that escaped bacteria may be the genesis of the ones that he and other researchers believe exist in tumors. “Because tumor microbes must come from somewhere, it is to be expected that some of those microbes will be co-opted from body-site specific commensals.”

It’s also possible that metabolites released from gut bacteria escape the gut and could theoretically affect distant tumor growth, Dr. Gihawi said. The most promising avenue of research in this area is metabolites being used as biomarkers, added Dr. Gihawi, whose lab published research on a link between bacteria detected in men’s urine and a more aggressive subset of prostate cancers. But that research is not far enough along to develop lab tests for clinical use, he noted. 
 

No Consensus Yet

Even before the controversy erupted around Dr. Knight’s research, he co-founded the company Micronoma to develop cancer tests based on his microbe findings. The company has raised $17.5 million from private investors as of August 2023 and received the US Food and Drug Administration’s Breakthrough Device designation, allowing the firm to fast-track clinical trials testing the technology. The recent critiques have not changed the company’s plans. 

It’s safe to say that scientists will continue to research and debate the possibility of tumor microbiomes until a consensus emerges. 

“The field is evolving and studies testing the reproducibility of tumor-resident microbial signals are essential for developing our understanding in this area,” Dr. Vujkovic-Cvijin said.

Even if that path ultimately leads nowhere, as Dr. Salzberg expects, research into microbiomes and cancer has plenty of other directions to go.

“I’m actually quite an optimist,” Dr. Gihawi said. “I think there’s a lot of scope for some really good research here, especially in the sites where we know there is a strong microbiome, such as the gastrointestinal tract.”

A version of this article appeared on Medscape.com.

TOPLINE:

A recent survey-based study found that only 4% of cancer survivors reported adhering to all four American Cancer Society (ACS) nutrition and physical activity guidelines, which include maintaining a healthy weight and diet, avoiding alcohol, and exercising regularly.

METHODOLOGY:

• The ACS has published nutrition and exercise guidelines for cancer survivors, which include recommendations to maintain a healthy weight and diet, cut out alcohol, and participate in regular physical activities. Engaging in these behaviors is associated with longer survival among cancer survivors, but whether survivors follow these nutrition and activity recommendations has not been systematically tracked.
• Researchers evaluated data on 10,020 individuals (mean age, 64.2 years) who had completed cancer treatment. Data came from the Behavioral Risk Factor Surveillance System telephone-based survey administered in 2017, 2019, and 2021, which represents 2.7 million cancer survivors.
• The researchers estimated survivors’ adherence to guidelines across four domains: Weight, physical activity, fruit and vegetable consumption, and alcohol intake. Factors associated with adherence were also evaluated.
• Overall, 9,121 survivors (91%) completed questionnaires for all four domains.

TAKEAWAY:

Only 4% of patients (365 of 9121) followed ACS guidelines in all four categories.

When assessing adherence to each category, the researchers found that 72% of cancer survivors reported engaging in recommended levels of physical activity, 68% maintained a nonobese weight, 50% said they did not consume alcohol, and 12% said they consumed recommended quantities of fruits and vegetables.

Compared with people in the general population, cancer survivors generally engaged in fewer healthy behaviors than those who had never been diagnosed with cancer.

The authors identified certain factors associated with greater guideline adherence, including female sex, older age, Black (vs White) race, and higher education level (college graduate).

IN PRACTICE:

This study highlights a potential “gap between published guidelines regarding behavioral modifications for cancer survivors and uptake of these behaviors,” the authors wrote, adding that “it is essential for oncologists and general internists to improve widespread and systematic counseling on these guidelines to improve uptake of healthy behaviors in this vulnerable patient population.”

SOURCE:

This work, led by Carter Baughman, MD, from the Division of Internal Medicine at Beth Israel Deaconess Medical Center, Boston, Massachusetts, was published online in JAMA Oncology.

LIMITATIONS:

The authors reported several study limitations, most notably that self-reported data may introduce biases.

DISCLOSURES:

The study funding source was not reported. One author received grants from the US Highbush Blueberry Council outside the submitted work. No other disclosures were reported.

A version of this article appeared on Medscape.com.

TOPLINE:

A recent survey-based study found that only 4% of cancer survivors reported adhering to all four American Cancer Society (ACS) nutrition and physical activity guidelines, which include maintaining a healthy weight and diet, avoiding alcohol, and exercising regularly.

METHODOLOGY:

• The ACS has published nutrition and exercise guidelines for cancer survivors, which include recommendations to maintain a healthy weight and diet, cut out alcohol, and participate in regular physical activities. Engaging in these behaviors is associated with longer survival among cancer survivors, but whether survivors follow these nutrition and activity recommendations has not been systematically tracked.
• Researchers evaluated data on 10,020 individuals (mean age, 64.2 years) who had completed cancer treatment. Data came from the Behavioral Risk Factor Surveillance System telephone-based survey administered in 2017, 2019, and 2021, which represents 2.7 million cancer survivors.
• The researchers estimated survivors’ adherence to guidelines across four domains: Weight, physical activity, fruit and vegetable consumption, and alcohol intake. Factors associated with adherence were also evaluated.
• Overall, 9,121 survivors (91%) completed questionnaires for all four domains.

TAKEAWAY:

Only 4% of patients (365 of 9121) followed ACS guidelines in all four categories.

When assessing adherence to each category, the researchers found that 72% of cancer survivors reported engaging in recommended levels of physical activity, 68% maintained a nonobese weight, 50% said they did not consume alcohol, and 12% said they consumed recommended quantities of fruits and vegetables.

Compared with people in the general population, cancer survivors generally engaged in fewer healthy behaviors than those who had never been diagnosed with cancer.

The authors identified certain factors associated with greater guideline adherence, including female sex, older age, Black (vs White) race, and higher education level (college graduate).

IN PRACTICE:

This study highlights a potential “gap between published guidelines regarding behavioral modifications for cancer survivors and uptake of these behaviors,” the authors wrote, adding that “it is essential for oncologists and general internists to improve widespread and systematic counseling on these guidelines to improve uptake of healthy behaviors in this vulnerable patient population.”

SOURCE:

This work, led by Carter Baughman, MD, from the Division of Internal Medicine at Beth Israel Deaconess Medical Center, Boston, Massachusetts, was published online in JAMA Oncology.

LIMITATIONS:

The authors reported several study limitations, most notably that self-reported data may introduce biases.

DISCLOSURES:

The study funding source was not reported. One author received grants from the US Highbush Blueberry Council outside the submitted work. No other disclosures were reported.

A version of this article appeared on Medscape.com.

TOPLINE:

A recent survey-based study found that only 4% of cancer survivors reported adhering to all four American Cancer Society (ACS) nutrition and physical activity guidelines, which include maintaining a healthy weight and diet, avoiding alcohol, and exercising regularly.

METHODOLOGY:

• The ACS has published nutrition and exercise guidelines for cancer survivors, which include recommendations to maintain a healthy weight and diet, cut out alcohol, and participate in regular physical activities. Engaging in these behaviors is associated with longer survival among cancer survivors, but whether survivors follow these nutrition and activity recommendations has not been systematically tracked.
• Researchers evaluated data on 10,020 individuals (mean age, 64.2 years) who had completed cancer treatment. Data came from the Behavioral Risk Factor Surveillance System telephone-based survey administered in 2017, 2019, and 2021, which represents 2.7 million cancer survivors.
• The researchers estimated survivors’ adherence to guidelines across four domains: Weight, physical activity, fruit and vegetable consumption, and alcohol intake. Factors associated with adherence were also evaluated.
• Overall, 9,121 survivors (91%) completed questionnaires for all four domains.

TAKEAWAY:

Only 4% of patients (365 of 9121) followed ACS guidelines in all four categories.

When assessing adherence to each category, the researchers found that 72% of cancer survivors reported engaging in recommended levels of physical activity, 68% maintained a nonobese weight, 50% said they did not consume alcohol, and 12% said they consumed recommended quantities of fruits and vegetables.

Compared with people in the general population, cancer survivors generally engaged in fewer healthy behaviors than those who had never been diagnosed with cancer.

The authors identified certain factors associated with greater guideline adherence, including female sex, older age, Black (vs White) race, and higher education level (college graduate).

IN PRACTICE:

This study highlights a potential “gap between published guidelines regarding behavioral modifications for cancer survivors and uptake of these behaviors,” the authors wrote, adding that “it is essential for oncologists and general internists to improve widespread and systematic counseling on these guidelines to improve uptake of healthy behaviors in this vulnerable patient population.”

SOURCE:

This work, led by Carter Baughman, MD, from the Division of Internal Medicine at Beth Israel Deaconess Medical Center, Boston, Massachusetts, was published online in JAMA Oncology.

LIMITATIONS:

The authors reported several study limitations, most notably that self-reported data may introduce biases.

DISCLOSURES:

The study funding source was not reported. One author received grants from the US Highbush Blueberry Council outside the submitted work. No other disclosures were reported.

A version of this article appeared on Medscape.com.