Breast Conservation Therapy versus Mastectomy in Patients with T1-2N1 Triple-Negative Breast Cancer: Pooled Analysis of KROG 14-18 and 14-23

Abstract

PurposeThe aim of this study is to compare the treatment outcomes of breast conserving surgery (BCS) plus radiotherapy (RT) versus mastectomy for patients with pT1-2N1 triple-negative breast cancer (TNBC).Materials and MethodsUsing two multicenter retrospective studies on breast cancer, a pooled analysis was performed among 320 patients with pT1-2N1 TNBC. All patients who underwent BCS (n=212) received whole breast RT with or without regional nodal RT, while none who underwent mastectomy (n=108) received it. All patients received taxane-based adjuvant chemotherapy. The median follow-up periods were 65 months in the BCS+RT group, and 74 months in the mastectomy group.ResultsThe median age of all patients was 48 years (range, 24 to 70 years). Mastectomy group had more patients with multiple tumors (p < 0.001), no lymphovascular invasion (p=0.001), higher number of involved lymph node (p=0.028), and higher nodal ratio. 0.2 (p=0.037). Other characteristics were not significantly different between the two groups. The 5-year locoregional recurrence-free, disease-free, and overall survival rates of BCS+RT group versus mastectomy group were 94.6% versus 87.7%, 89.5% versus 80.4%, and 95.0% versus 87.8%, respectively, and the differences were statistically significant after adjusting for covariates (p=0.010, p=0.006, and p=0.005, respectively).ConclusionIn pT1-2N1 TNBC, breast conservation therapy achieved better locoregional recurrence-free, disease-free, and overall survival rates compared with mastectomy.