Despite advancements in early detection and innovative treatments, Black women in the United States face higher mortality rates from breast cancer compared to white women. A systematic review and meta-analysis led by Mass General Brigham Integrated Health Care System sheds light on the extent of these disparities across different breast cancer subtypes.
The study, published in the Journal of Clinical Oncology, aimed to determine the disparities in breast cancer survival between Black and white women according to tumor subtype. Researchers conducted a comprehensive analysis of 18 studies published between 2000 and 2022, including data on 228,885 breast cancer cases—34,262 of which were in Black women. The different types were determined by the presence of human epidermal growth factor receptor 2 (HER2) and hormone receptor status. HER2 is a protein that is linked to more aggressive cancer.
The results revealed that Black women have a significantly higher risk of breast cancer mortality across all tumor subtypes. Specifically, the risk of death was 50% higher for hormone receptor-positive, HER2-negative tumors, 34% higher for hormone receptor-positive, HER2-positive tumors, 20% higher for hormone receptor-negative, HER2-positive tumors, and 17% higher for hormone receptor-negative, HER2-negative tumors. The findings indicate that disparities are present even in the most treatable forms of breast cancer.
“Our findings demonstrate that multiple, interacting factors contribute to disparities in breast cancer survival between Black and white women,” said senior author Dr. Erica Warner, ScD, MPH, a cancer epidemiologist at Massachusetts General Hospital. “To achieve equity, intervention is necessary at multiple levels—from community to healthcare systems and individual healthcare providers to patients themselves learning about their disease and what their expectations should be for their care.”
Along with Warner, the study’s co-authors were Dr. Paulette Chandler, Juliana M. Torres, Michelle O. Sodipo, and Margaret F. Hopkins. The study calls for concerted efforts at all levels of the healthcare system to ensure that Black women receive the quality of care necessary to reduce breast cancer mortality rates.
Breast cancer remains the most diagnosed cancer among U.S. women and is the second leading cause of cancer death. Reportedly, Black women are about 40% more likely to die from breast cancer than white women. Until this study, researchers said it was unclear if this disparity existed across all breast cancer subtypes.
The study contends that several factors, including systemic racism, socioeconomic inequality, delays in cancer diagnosis, and inadequate access to high-quality cancer treatment, contribute to these disparities. These factors can affect the timeliness and effectiveness of treatment, regardless of the biological nature of the tumor.
“There had been an anecdotal sense in the research community that differences in survival between Black and White women were greater for the most treatable forms of the disease—tumors that carry hormone receptors—and smaller for the historically less-treatable, hormone-negative tumors,” Warner explained.
The study confirms that disparities are indeed present across all subtypes, though they vary in magnitude.
“These findings underscore a stark reality in our healthcare system (that) Black women are facing higher risks of death from breast cancer compared to their white counterparts, across all types of the disease,” Chandler, emphasized. “This disparity isn’t just about biology. It’s a call to action for healthcare providers, policymakers, and communities alike to confront these inequities head-on and strive for meaningful change in breast cancer outcomes.”
The researchers highlight the need for multilevel interventions to achieve health equity.
Programs that have successfully reduced disparities in cancer survival include those that help patients navigate the healthcare system, proactively identify social needs, and connect patients with necessary resources.
Additionally, the study points to the potential impact of the underrepresentation of Black women in clinical trials, which may result in therapies not being adequately tailored to specific tumor subtypes.
However, researchers concluded that the disparities are not inevitable. With targeted, multilevel interventions, the authors said it is possible to close the gap in breast cancer outcomes and achieve health equity.