Research from the University of Notre Dame reveals biological differences that may explain why Black women experience more aggressive breast cancers and higher mortality rates compared to white women. While breast cancer incidence is highest among white women, Black women are more likely to develop early-onset or aggressive subtypes like triple-negative breast cancer.
The disparity becomes stark among younger women. Young Black women under 50 have double the mortality rate of young white women with breast cancer, according to the study published in iScience.
Scientists discovered that a specific population of cells called PZP cells may contribute to this health inequality. These cells are naturally and significantly higher in healthy breast tissues of women of African ancestry compared to women of European ancestry. The research showed that PZP cells send signals that prompt other breast cells to become invasive and detach from their original location.
“The disparity in breast cancer mortality rates, particularly among women of African descent, is multifaceted,” said Crislyn D’Souza-Schorey, the study’s corresponding author and Morris Pollard Professor of Biological Sciences at Notre Dame. She noted that while socioeconomic factors and delayed diagnosis contribute, “substantial emerging evidence suggests that biological and genetic differences between racial groups can also play a role.”
The findings emphasize the need for inclusive cancer research and treatment approaches that account for biological variations across racial groups to improve outcomes for all women.
See: “Women of African ancestry may be biologically predisposed to early onset or aggressive breast cancers” (July 24, 2025)
