A new study reveals that Black women are more likely than white women to die from even the most treatable types of breast cancer.
Published Tuesday in the Journal of Clinical Oncology, the findings underscore that racial disparities, not biology, drive the stark differences in death rates between Black and white women. While both groups are diagnosed with breast cancer at similar rates, Black women are 40% more likely to die from the disease.
“Within health care, there was this notion that an important contributor to disparities was that Black women have higher rates of triple-negative breast cancer, a particularly aggressive type,” said lead author Erica Warner, a cancer epidemiologist at Massachusetts General Hospital.
RELATED STORIES
Although this plays a role in higher death rates, Warner emphasized, “Based on these results, it isn’t a significant or primary reason.”
Warner and her colleagues conducted a meta-analysis of 18 studies involving nearly 230,000 breast cancer patients, 34,000 of whom were Black. They compared the mortality rates of Black and white women with the same breast cancer subtypes.
A cancer’s subtype affects how a tumor behaves and responds to treatment, which greatly influences mortality. Breast cancer subtypes are categorized by the receptors found on the tumor cells. Hormone receptor-positive (HR-positive) tumors have receptors for estrogen or progesterone, while HER2-positive tumors have a receptor that helps the cancer spread but can also respond well to targeted treatments. Tumors lacking these receptors are triple-negative, the hardest to treat.
For the most common subtype, HR-positive, HER2-negative (60% to 70% of all breast cancer diagnoses), Black women were 50% more likely to die than white women. For HR-positive, HER2-positive cancers, Black women were 34% more likely to die. Surprisingly, Black women were also 17% more likely to die from triple-negative breast cancer than white women, despite both groups having high mortality rates for this subtype.
“We expected to see the biggest disparities with hormone receptor-positive tumors, but not for triple-negative cancers,” Warner said. “In reality, we observed similar disparities across all subtypes.”
Racial Disparities, Not Biology, Are the Key Drivers
Dr. Eric Winer, director of the Yale Cancer Center, said the greatest disparities for hormone receptor-positive cancers highlight the impact of socioeconomic factors. Extended hormone therapy, which lasts for five or more years, often comes with significant out-of-pocket costs, making it less accessible for some.
“People are falling through the cracks, whether due to economic constraints or other barriers to accessing or adhering to treatment,” Winer said. He added that doctors may be less likely to offer extended therapies to Black or low-income patients. While not all Black women are low-income or uninsured, data from the Centers for Disease Control and Prevention show that Black patients are more likely to lack insurance.
Structural barriers like these are often overlooked, according to Dr. Wendy Wilcox, chief women’s health officer at New York City Health + Hospitals. Social determinants of health — including access to health care, child care, transportation, time off work, healthy food, and clean environments — all contribute to differences in health outcomes.
“There has been a long-standing lack of Black women in clinical trials,” Wilcox added. “From the earliest stages of breast cancer research, Black women are underrepresented.”
Black women are also more likely to be diagnosed with breast cancer at a younger age and at more advanced stages.
“Early detection is critical, regardless of subtype,” said Dr. Marissa Howard-McNatt, director of the Breast Care Center at Atrium Health Wake Forest Baptist. “Black women often get breast cancer in their 30s, but screening doesn’t typically begin until age 40.”
Howard-McNatt emphasized the importance of family history in screening. Women should start mammograms 10 years before a parent or sibling was diagnosed with breast cancer.
She also highlighted the value of patient navigators, who help patients understand treatment options and manage logistics like transportation. Providing access to such resources could help reduce the disparities Black women face.
Historically, there were no significant differences in breast cancer mortality between Black and white women.
“If you look at data from 40 years ago, mortality rates were similar. But as treatments have improved, the gap between white and Black women has widened,” Warner said. “That’s concerning, but it also shows us that we have control over these disparities. If we can create them, we can eliminate them.”
