Racial differences in pathologic complete response rate and clinical outcomes following neoadjuvant chemotherapy for breast cancer

PURPOSE: Neoadjuvant chemotherapy (NAC) is commonly used in early-stage breast cancer. A complete pathologic response (pCR) after NAC is associated with improved outcomes. This study investigated differences in pCR and clinical outcomes by race. METHODS: A single-institution, retrospective chart review identified patients with early-stage breast cancer who received NAC between January 1, 2010, and December 31, 2017. Associations between race and pathologic and clinical outcomes were evaluated using multivariable logistic regression and Cox proportional hazard models. Kaplan-Meier estimates and log rank tests assessed differences in recurrence-free survival (RFS) and overall survival (OS). RESULTS: A total of 532 patients with breast cancer of all receptor subtypes were identified; 323 (60.7%) White, 188 (35.3%) Black and 21 (3.9%) other/unknown. The pCR rate was different between the 3 race categories; White 27.2%, Black 19.1% and other/unknown 9.5% (P = 0.03). In multivariate analysis, pCR rates were higher in White versus Black patients (P = 0.02). Patients with triple-negative disease demonstrated the largest difference in pCR (White 44.3% versus Black 27.1%; P = 0.04). Black patients had inferior OS compared to White patients (P = 0.03). There was no difference in RFS by race (P = 0.07). CONCLUSION: Black patients demonstrated a lower pCR rate compared to White patients, and this was more pronounced in the triple-negative subgroup. There was no difference in RFS by race, but OS was inferior among Black patients. It is possible that the lower pCR rate in Black patients may contribute to lower OS; however, more investigation is needed to explain these differences.