Study: Black women should start breast cancer screening at age 42

For many years, there’s been considerable debate about the best age for women to initiate breast cancer screening. The U.S. Preventive Services Task Force recommends that women start getting mammograms at age 50, making individual decisions with their doctors about whether to screen in their 40s.  Groups such as the American Cancer Society, meanwhile, recommend screenings begin at an earlier age. Now a large new study suggests that if Black women begin screening for breast cancer at age 42, that could help lower racial disparities in breast cancer deaths.

Breast cancer is slightly less prevalent among Black women in the U.S. compared to white women. But they have a 40% higher risk of dying due to early-onset breast cancer. For that reason, “the current one-size-fits-all policy to screen the entire female population from a certain age may be neither fair nor equitable nor optimal,” researchers write in the study published Wednesday in JAMA Network Open. 

To determine the age at which women of different races could start screening for breast cancer based on their risk, the researchers looked at a total of 415,277 breast cancer deaths in female patients in the U.S. from 2011 to 2020 in a dataset that included race and ethnicity. The findings suggested that Black women should start screening at age 42; white women at 51; American Indian, Alaska Native, and Hispanic women at 57; and Asian or Pacific Islander women at 61.

In earlier studies, the cancer prevention group that study author Mahdi Fallah leads at the German Cancer Research Center had included other risk factors, such as the age at which women first gave birth, to determine the recommended age of first screening. But for this study, they looked at race and ethnicity — which, scanning medical literature for other risk factors, they found to be an important factor associated with an earlier or later development of breast cancer. 

The results for Asian or Pacific Islander women, and to a certain extent for American Indian or Alaska Native and Hispanic women, were unexpected, Fallah said in an email. The findings suggest that continuing to apply a universal age guideline for breast cancer screenings could harm not only Black women, but also lower-risk women. The current recommendations might lead to over-diagnosis and exposure to radiation for mammograms for some women at an earlier age than necessary, Fallah said. 

“Adjusting the recommended age for initiation of breast cancer screening for risk factors such as race and ethnicity … is the solution to the problem,” he said. 

Some experts STAT talked to considered the study a well-designed one, particularly its use of recent data in a large dataset, and inclusion of risk factors like age, race, and ethnicity.  

“Breast cancers do occur earlier in certain populations,” said Joannie Ivory, chief fellow of the oncology division at the University of North Carolina, noting that she sometimes sees patients diagnosed with breast cancer in their 30s. “I think what the [authors] are attempting to do is actually trying to provide us with some evidence-based study to help guide our conversations with patients.”

Still, experts caution that, since this study does not use mammogram screening data, basing screening recommendations on its findings is problematic. The authors acknowledge that they were limited by a lack of data for both the mode of cancer detection and past screening history. While the risk level for cancer death is associated with when and how the cancer is detected, the database the researchers used includes a mix of women who didn’t get screened, got screened infrequently, or were screened regularly before being diagnosed, the authors noted. 

But since there’s no consensus about breast cancer screening before age 50, conclusions based on breast cancer death before age 50 in Black women, which was the focus of the study, “may not have been substantially affected by this issue,” the authors wrote.

“Even if some Black women had breast cancer screening before age 50, which is quite unlikely, our risk estimates for breast cancer mortality and therefore Black-specific starting age of screening would be under-estimated rather than over-estimated,” Fallah told STAT.

The study’s authors suggest that future clinical trials might investigate whether shifting current breast cancer screening guidelines could change outcomes and reduce harms at the population level. Experts told STAT prospective studies that account for factors like women’s socioeconomic status, ZIP codes, their age, and the frequency of mammogram screenings would provide more solid data.  

“Race is still something that we’re trying to figure out — how that puzzle piece fits into the bigger picture of risk,” said Dionisia Quiroga, a breast medical oncologist with The Ohio State University Comprehensive Cancer Center – James Cancer Hospital and Solove Research Institute.   

The race and ethnicity data in this study, which was reported by proxy based on death certificates, might also be less accurate than if self-reported, so future prospective studies could fill this gap, Quiroga said. 

Meanwhile, clinicians should take a woman’s race and ethnicity into account when advising them when to begin screening, the authors wrote. 

Some clinicians, like Lisa Newman, a surgical breast oncologist at Weill Cornell Medicine, stand by age 40 as a good starting age for any woman at high risk. She and other experts told STAT they would be reluctant to advise women of any ethnic or racial group to screen later than age 50. Individuals’ risk factors vary within and outside these groups, and many non-white women also struggle with access to quality care, providers’ implicit biases and systemic inequities just as Black women do, they said. The data analysis also doesn’t differentiate between Black Hispanic and non-Black Hispanic women, Quiroga noted. 

In addition to screening Black women at an earlier age, clinicians might consider more frequent screenings and alternatives to mammograms, the authors wrote. Black women tend to have higher breast density, which makes it tougher for radiologists to identify breast cancer on a mammogram, while also raising the risk of breast cancer. 

They’re also much more likely to develop more aggressive cancers, including an invasive subtype known as triple-negative breast cancer. The Carolina Breast Cancer Study showed that, with early-stage breast cancer, Black women have a higher frequency of other molecular subtypes that can become resistant to treatment, and ultimately lead to poor health outcomes, Ivory said. But the study couldn’t take cancer subtype or stage of the disease into account due to limited data, the authors acknowledged.  

The benefits of earlier breast cancer detection would balance out any harms from false positives due to the dense breast tissue in this group, the researchers noted. 

There are systemic reasons why Black women might not get screened earlier and often. Implicit bias from providers, disparities around the quality and access to care Black women receive, and mistrust in the medical system are just a few, experts told STAT. 

“A lot of Black women are the sole provider in their family, and so, in order for them to be able to go and get screened, or be able to get treatment, which can be frequent visits, they have to take time off from work,” Ivory said. “But when you’re the sole provider for your family, then is that really possible for you to do? As a result, sometimes women put their own needs on the back burner to take care of their family.” 

This story has been updated.