A new study suggests that a poor response to neoadjuvant chemotherapy-frequently administered to black, Hispanic, and Asian women-could dictate survival rates in breast cancer.
Disparities in cancer have been a subject of research for a while. According to the National Cancer Institute, white women have the highest incidence rate for breast cancer but black women are more likely to die of the disease. While issues with access to care or screening and limitations placed by health coverage could contribute to the difference in survival, a new study suggests that a poor response to neoadjuvant chemotherapy—frequently administered to black, Hispanic, and Asian women—could also dictate survival rates in breast cancer.
Published in the Journal of Clinical Oncology, the study utilized information from the National Cancer Database on women with stage 1 to 3 breast cancer. More than 45% of the 278,815 patients with known race and ethnicity information received chemotherapy; among 121,446 patients in whom the timing of chemotherapy was known, 27,300 (23%) received neoadjuvant chemotherapy. The authors discovered that the rate of neoadjuvant chemotherapy was especially high in black, Hispanic, and Asian women than in white women. The driving force for administering chemotherapy prior to surgery was the advanced stage of disease, higher grade tumors, and higher number of triple-negative and HER2-positive tumors in the non-white population in the study.
“Even when we controlled for the fact that minority women often present with more advanced-stage, higher-grade tumors, and more aggressive types of breast cancer overall, our team was surprised to find that black women did not respond as well to neoadjuvant chemotherapy compared to other racial groups,” said lead author Brigid K. Killelea, MD, Department of Surgery, Yale University School of Medicine. Donald Lannin, MD, professor of surgery (oncology) and senior author on the study, proposed that future studies should identify those drugs that generate a response from black women to ensure they are treated with medications that they benefit from.
The analysis showed that while 33% (5944) of women had a pathologic complete response (independent of hormonal receptor status), the rate of response was much worse among the black women in the cohort compared with the white women (37% vs 43% for triple-negative tumors, P<.001; (43% vs 54% for HER2-positive tumors, P = .001). The authors write that the difference endured variations in age, clinical stage, geographic region, insurance status, and median income and education. Overall, the results suggest that black women have a lower likelihood of pCR for triple-negative and HER2-positive breast cancer, either due to biological differences in chemosensitivity or socioeconomic differences, they conclude.