For years, health experts have recommended that, starting at the age of 50, every woman should get a mammogram every two years. But Christina Chapman, an oncologist and researcher at the University of Michigan, looked at the devastating disparities in breast cancer outcomes for Black women and wondered whether medicine could serve Black women better with a different recommendation just for them.
Fewer women die of the disease now than 20 years ago, partly thanks to mammograms, but that progress has not been equal. Black women have historically died from breast cancer at higher rates than white women, and that gap has widened in recent years despite a decline in the overall mortality rate.
“In addition to the higher death rate, Black women are likely to get cancer at younger ages, a more aggressive subtype, and not receive adequate treatment as often,” Chapman said. “When you consider all these factors, it means Black women might benefit from a different screening schedule compared to other populations.”
Chapman set out to study whether breast cancer disparities would start to dry up if Black women started receiving screening a decade earlier than white women. It’s nearly impossible to pull together the time, money, and participants to run an experiment like this in the real world, she said. So, cancer researchers often use a statistical model known as CISNET to test different screening scenarios.
Chapman and her team modified this model to include race and simulated 100 million digital lives to see what would happen if Black women began mammograms at age 40. The model predicted starting screenings earlier would reduce breast cancer deaths in Black women enough to shrink the gap in breast cancer deaths among Black women and white women by 57%. They reported their findings in Annals of Internal Medicine on Monday.
“One really important part of that is screening 10 years earlier [in Black women] results in the same values of benefits and harms of screening white women at age 50 and saves more lives,” Chapman said. “We consider that equity.” Screening authorities like the U.S. Preventive Services Task Force — an independent panel that sets screening recommendations largely followed in the U.S. — could take her results into consideration to help achieve health equity, Chapman said.
Chapman and other experts emphasized that the disparities seen in breast cancer outcomes are not directly related to race, which is not a biological construct. “It’s rooted in racism, where Black women are less likely to have health insurance, less likely to have high-quality care,” she said. “That’s based on someone who looks Black and that Black appearance results in them receiving racism.”
In reality, cancer screening is rife with trade-offs, said Michael Hassett, an oncologist at Dana-Farber Cancer Institute who wasn’t involved in the research. Mammograms aren’t perfect. Sometimes they have false positives, which can result in unnecessary follow-ups and painful biopsies. Other times, they might detect a tumor that’s cancerous but, paradoxically, not dangerous because its growth is so slow. These women may end up getting unneeded treatments and surgeries that have their own risks and harms. The more you screen, the more likely these unintended outcomes become.
In a perfect world, doctors would know exactly which patients have higher risk for breast cancer and which ones don’t. Then, Hassett said, they’d be able to screen the highest-risk patients earlier and more frequently, and the lower-risk patients less. “It makes a lot of sense to adapt screening to patient characteristics,” Hassett said. “The next question is, what are the factors that should be included in that approach? Is self-identified race one of those factors?”
In the past, attempts to use race in medical decision-making have caused harm, said David Jones, a medical historian at Harvard University, partly because they wrongly assumed people of a single self-categorized race share certain biology or even certain life experiences. “If you see someone with dark skin or self-identifies as Black, do you know anything about their experience of racism?” Jones said. “They may have nothing in common. Why would you assume that they do?”
In an editorial also published in Annals of Internal Medicine on Monday, Jones argued that creating breast cancer screening guidelines based solely on race might lead to more harm than suggested by the paper. For one, Jones said creating a guideline like recommending all Black women start screening at age 40 means some Black women who were never at a high risk for breast cancer would still get a decade of extra mammograms. And, he added, such a guideline would perpetuate the idea that race is a biologically meaningful category, when it isn’t.
“Rather than exposing Black women to 10 years of false positives, radiation and what else, we should do the work to find other markers to guide our decisions. I wanted sophisticated research on human diversity. Ancestry, age, gender, socioeconomic status, and race — not just Black and white,” Jones said. “That’s easy for me to say, though. I don’t have to do that work.”
There are so many things that influence cancer risk — ancestry, genetics, income, insurance status, and more — that ensuring the exact right patients get screened at the perfect amount is hard on an individual level. At present, it’s restrictively hard on a population level. “The more complicated we make screening, the harder it is to make sure everyone is screened according to the guidelines,” Hassett said.
So, Hassett said, it makes sense to try and figure out just how personalized screening guidelines can be – and pick and choose a limited number of factors, like race, to base them on. Hassett said it’s up to authorities like the USPSTF to figure out which ones — a difficult and important task. Most private insurance plans are required to cover certain treatments and screenings recommended by the USPSTF without any copay.
“I think I’m glad I’m not the U.S. Preventive Services Task Force,” Hassett said.
Chapman said self-reported race, based on her findings, makes sense. African Americans have different backgrounds and experiences, Chapman explained, but their work reflects the population — not individual experiences. That said, there’s a need for more new clinical trials on breast cancer screening, Chapman added. Their model, and many others, use data from trials that were done over a decade ago.
“Black women weren’t included in large numbers in screening trials then,” she said.
Plus, mammography technology has improved significantly. Breast cancer screening today has different risks than it did in the ’80s and ’90s. A sweeping new screening trial would be very expensive, and Hassett believes the lack of such research holding the field back. A new trial would allow scientists to better study many of the factors that contribute to breast cancer risk — including race.
“There’s a lot of questions in this space that we are not and will never be able to answer because we’re still saddled with old data,” Hassett said. “At some point, we will have to bite the bullet and do another screening trial to update our understanding.”