New research suggests that a common test used to guide breast cancer treatment decisions may be giving inaccurate recommendations for Black women. The study, published in the Journal of the National Comprehensive Cancer Network, focused on more than 73,000 women with early-stage, estrogen receptor (ER)-positive breast cancer who underwent the 21-gene breast recurrence score, a widely used test that helps determine prognosis and the effectiveness of post-surgical chemotherapy.
Surprisingly, the results indicated that the test may be underestimating the potential benefits of chemotherapy, especially for Black women and younger Black women who could actually benefit from the treatment. Dr. Kent Hoskins, a professor of oncology at the University of Illinois Chicago and the study author, expressed concern that the test might be guiding treatment in the wrong direction.
For ER-positive breast cancer, the standard treatment involves estrogen blockade with or without chemotherapy, determined by the 21-gene breast recurrence score. However, Black women may not respond as well to hormone therapy, and the addition of chemotherapy could be more beneficial for them, according to the researchers.
Previous studies have already highlighted racial disparities in survival for women with ER/progesterone-receptor (PR)-positive breast cancer. The recent findings suggest that the test cutoffs determining chemotherapy treatment might need reevaluation, especially as Black individuals, when analyzed by age, showed a higher likelihood of breast cancer-related death.
The research emphasized that doctors might need to reconsider using the same cutoffs and tests for everyone, regardless of race or ethnicity, due to underlying biological differences. Dr. Hoskins pointed out that while biological differences play a role, social factors like structural racism and access to care also impact breast cancer outcomes in Black women. The research team is conducting further studies to explore these aspects.