Neo-adjuvant doxorubicin and cyclophosphamide followed by paclitaxel in triple-negative breast cancer among BRCA1 mutation carriers and non-carriers.

The purpose of this study was to assess pathological complete response and whether it serves a surrogate for survival among patients receiving neo-adjuvant doxorubicin-cyclophosphamide followed by paclitaxel for triple-negative breast cancer with respect to BRCA1 mutation status. From a neo-adjuvant systemic therapy database of 588 breast cancer cases, 80 triple-negative cases who had undergone BRCA genotyping were identified. Logistic regression model was fitted to examine the association between BRCA1 status and pathological complete response. Survival outcomes were evaluated using Kaplan-Meier method, differences between study groups calculated by log-rank test. Thirty-four BRCA1 carriers and 43 non-carriers were identified. The BRCA1 carriers had pathological complete response rate of 68 % compared with 37 % among non-carriers, p = 0.01. Yet this did not translate into superior survival for BRCA1 carriers compared with non-carriers. No difference in relapse-free survival were noted among those with or without pathological complete response in BRCA1 carriers regardless of pathological complete response status (Log-rank p = 0.25), whereas in the non-carrier cohort, relapse-free survival was superior for those achieving pathological complete response (Log-rank p < 0.0001). Response to neo-adjuvant systemic therapy differed in BRCA1-associated triple-negative breast cancer compared with triple-negative non-carriers, with a higher rate of pathological complete response. However, compared with non-carrier triple-negative breast cancer, pathological complete response was not a surrogate for superior relapse-free survival in BRCA1 patients. Future studies using specific chemotherapy regimens may provide further improvements in outcomes.