Oncological safety of breast-conserving surgery after primary systemic chemotherapy in cT3-4 breast cancer patients.

Abstract

The aim of this study was to retrospectively assess the oncological safety of breast-conserving surgery (BCS) after primary systemic chemotherapy (PST) in terms of local recurrence (LR) in cT3-4 patients. The subjects were 146 cT1-2 patients who underwent BCS after PST, and 169 patients with cT3-4 primary breast cancer. Of the 169 patients with cT3-4 disease, 20 underwent surgery first, and 149 underwent surgery after PST (mastectomy: 101 patients; BCS: 48 patients). The LR-free survival (LRFS) was analyzed using a Kaplan-Meier analysis. We evaluated the predictors using Cox proportional hazards modeling for LR after PST. There was no significant difference in 5-year LRFS between the cT1-2 and cT3-4 groups that underwent BCS after PST (98.6 vs. 92.5 %; P = 0.074). The 5-year LRFS was 94.7 % in the group that underwent initial surgery and 93.0 % in the PST group (P = 0.845) in the cT3-4 patients, while the 5-year LRFS rates were 93.2 % in the BCS subgroup and 92.5 % in the mastectomy subgroup (P = 0.958). In a multivariate analysis, the histological type, hormone negativity and a higher histological grade were independent predictors of LR after PST. BCS after PST may be oncologically acceptable for cT3-4 breast cancers in terms of the LR compared with initial surgery or mastectomy after PST.