A breast cancer diagnosis can be especially scary for Black women. While we develop breast cancer less often than white women, they are more likely to die from it. A new study suggests that DNA could be the key to curbing racial disparities in breast cancer survival.
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To put the odds into perspective, Black women have a 4 percent lower incidence rate of breast cancer than white women do, but they have a 40 percent higher mortality rate, according to the American Cancer Society. While socioeconomic and geographical disparities, like being uninsured or underinsured and lacking access to medical care, contribute to higher rates of death, a study published in npj Breast Cancer found a missing link: Black women were twice as likely to have aggressive tumors as white women, and traditional testing often misses this type of tumor.
DNA Offers a Clearer Picture
According to breastcancer.org, traditional testing includes categorizing breast cancer. The new study took a different approach, analyzing tumor DNA. Led by Sonya Reid, a Black physician and assistant professor of medicine at Vanderbilt University Medical Center, the researchers examined tumors from more than 1,000 Black and white women. All had HR-positive, HER2-negative early breast cancer, with comparable age and their menopausal status, as Pharmaphorum reported.
The researchers used genomic tests to examine tumor DNA and guide treatment. The specific tests used were MammaPrint and BluePrint. They found that despite varying levels of tumor aggression, the three-year outcomes between Black and white women were the same, essentially erasing the survival gap. According to Pharmaphorum, the findings suggest that Black women have been under-treated for breast cancer. DNA-guided treatment helped to improve outcomes and reduce the risk of cancer recurrence.
“By providing a genomic assessment of tumor biology, we can ensure that women with breast cancer will receive individualized care that improves their long-term outcomes,” William Audeh, co-author of the study and chief medical officer of Agendia, said. This is supported by long-term data from the study, which found that Black women in the BEST registry whose tumors were classified as low-risk by the MammaPrint test were just as likely to be cancer-free a decade later as their white counterparts; their 10-year recurrence-free rate was 97.7 percent.
A Representation Problem
Medical science has routinely left Black women out of the equation. According to Pharmaphorum, a 2022 study found that 42 percent of cancer trials conducted over a 15-year span had included no Black patients at all.
The findings from this latest study could begin to fill in the gaps and make the case for broader use of DNA-guided treatment that narrows the survival gap for Black women.
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