Breast conserving surgery versus salvage mastectomy for ipsilateral breast cancer recurrence: a propensity score matching analysis.

Salvage mastectomy is regarded as the treatment of first choice for ipsilateral breast cancer recurrence (IBCR), even if a second breast conserving surgery (BCS) is feasible. The purpose of this study was to compare the long-term oncological outcomes of IBCR patients who had undergone either mastectomy or second BCS, performing a propensity score matching (PSM) analysis to reduce the selection bias. All the consecutive patients with IBCR were retrospectively reviewed and divided into two different groups of treatment: repeat BCS versus salvage mastectomy. The propensity score predicting the probability of surgical treatment was determined for each patient and a 1:1 matching was performed. Disease-free survival (DFS), distant disease-free survival (DDFS), overall survival (OS), and breast cancer-specific survival (BCSS) were analyzed and compared between the two groups. A total of 309 patients underwent surgical treatment for IBCR. After PSM, 108 patients treated with repeat BCS and 108 patients treated with salvage mastectomy were included in the analysis. There was no significant difference in terms of DFS between patients with IBCR receiving repeat BCS or salvage mastectomy (p = 0.167). However, patients with IBCR undergoing second BCS had significantly better DDFS, OS, and BCSS compared to salvage mastectomy (p < 0.001). Salvage mastectomy should not be considered the optimal treatment for IBCR and it does not seem to improve prognosis compared to repeat conserving surgery. Second BCS for IBCR is a safe option with encouraging long-term oncological outcomes and should be proposed to all patients, when technically feasible.