Efficacy of adjuvant chemotherapy with carboplatin for early triple negative breast cancer: a single center experience

BACKGROUND: Anthracycline- and taxane-based adjuvant chemotherapies are the most frequently used systemic treatments for women with triple negative breast cancer (TNBC). Adding platinum derivatives in the neo-adjuvant setting has been shown to not only improve the pCR rates, but also the 3 year DFS for TNBC patients; however, data on platinum derivatives in the adjuvant setting are limited. METHODS: We conducted a retrospective, single-center study in a Swiss breast cancer cohort to evaluate the role of carboplatin in addition to standard adjuvant therapy (anthracyclines and/ or taxanes) in early TNBC patients. All patients with stage I-III TNBC who underwent primary breast surgery between 2004 and 2014 were included. RESULTS: Eighty-three patients were included in the analysis. Stage and grade were well balanced between patients treated with standard chemotherapy (N=54; cohort A) or standard chemotherapy plus carboplatin (N=29; cohort B). The median time to local relapse (LRFS) was 15.0 months in cohort A versus 16.0 months in cohort B (p=0.655). The median time to distant relapse (DRFS) was 29.5 months in cohort A versus 25.0 months in cohort B (p=0.606) There was also no difference in overall survival between the two cohorts (mean overall survival 98 and 91 months, respectively; p=0.208). DISCUSSION: Our data suggest that in an unselected cohort of early TNBC patients, the addition of carboplatin in the adjuvant setting may not be beneficial with respect to relapse-free and overall survival. Further prospective trials to evaluate the addition of platinum in the adjuvant setting are warranted, especially to define subgroups of TNBC patients, which might benefit from carboplatin therapy.