High Biomarker Testing Rates Achieved Across Racial Groups in Metastatic Triple-Negative Breast Cancer, Yet Disparities Persist
A study of 450 mTNBC patients in community practices found high biomarker testing rates and encouraging outcomes across racial groups, with Hispanic patients showing the longest survival. However, Black women of West African ancestry face the highest TNBC incidence and greater neuropathy from paclitaxel, making docetaxel a potential alternative. Social determinants like neighborhood deprivation and allostatic load are also linked to TNBC risk.
A real-world study of 450 patients with metastatic triple-negative breast cancer (mTNBC) across 25 U.S. community oncology centers found that high rates of guideline-recommended biomarker testing were achieved across racial groups, and outcomes suggested that coordinated care may mitigate some historical inequities.
The analysis, presented at the Miami Breast Cancer Conference, included 270 White, 105 Black, 45 Hispanic, and 30 patients of other minority groups diagnosed between 2018 and 2023. Testing rates for PD-L1 expression reached 76.2% and for BRCA1/2 mutations 78.0% overall. Systemic therapy was received by 93.3% of Hispanic patients, compared with 83.7% of White, 81.0% of Black, and 76.7% of other minority patients.
Hispanic patients demonstrated the highest probability of survival at 12 months and the longest median overall survival. The authors concluded that high rates of biomarker testing and timely treatment can be achieved across racial groups, and that outcomes between Black and White patients suggest community oncology networks may help reduce disparities.
Despite these encouraging findings, triple-negative breast cancer disproportionately affects certain populations. A surgical oncology specialist at The James, The Ohio State University Comprehensive Cancer Center noted that Black women of West African ancestry have the highest incidence of TNBC.
Treatment toxicity can pose additional barriers. Research has shown that Black women may experience higher rates of neuropathy, leading to treatment discontinuation and potentially affecting long-term survival. The ECOG-ACRIN EAZ171 study, presented at the 2024 ASCO Annual Meeting, found that paclitaxel was associated with more grade 2 to 4 taxane-induced peripheral neuropathy in Black women and required more dose reductions compared with docetaxel, suggesting that docetaxel might be a preferable option.
Immunotherapy represents a major advance for TNBC, improving survival. Social and environmental factors also play a role: women living in neighborhoods with high deprivation are more likely to be diagnosed with TNBC, and higher allostatic load—a measure of chronic biological stress—has been associated with the disease. The specialist emphasized the importance of a personalized, multimodal approach that aligns with each patient's values.