Are the Outcomes of Breast Conservation Surgery Inferior to Those of Mastectomy in Patients with Stage II-IIIA Triple-Negative Breast Cancer?

Abstract

Purpose: Breast conserving surgery (BCS) is generally not considered for breast cancer because of concerns about the poor prognosis of triple negative breast cancer (TNBC). We assessed the outcomes of BCS and mastectomy for patients with stage II-IIIA TNBC.Methods: The data of 172 breast cancer patients diagnosed with stage II-IIIA TNBC who underwent treatment at Pusan National University Hospital and Pusan National University Yangsan Hospital from 2010 to 2014 were retrospectively analyzed. The patients were divided into the following two groups: patients who underwent BCS (n=101) and those who underwent mastectomy (n=71). The Cox regression model was used to examine the outcomes of both treatments. The median follow-up period was 71 months in the BCS group, and 67 months in the mastectomy group.Results: The median age of the 172 patients was 51 years (range, 22-82 years). In the BCS group, radiation therapy and chemotherapy (p<0.001 and p=0.007, respectively) were performed more frequently. The BCS group had more patients with a high Ki-67 index (p=0.006), while the mastectomy group included more patients with a higher pathologic T (pT) stage (p=0.005). The 5-year loco-regional recurrence-free, disease-free, and overall survival rates of the BCS group versus the mastectomy group were 93.8% versus 95.3%, 89.8% versus 90.7%, and 90.8% versus 86.3%, respectively, but the differences were not statistically significant. Lymphovascular invasion was a risk factor for disease-free survival and advanced stage was an important risk factor for overall survival.Conclusion: In stage II-IIIA TNBC, BCS was not inferior to mastectomy in locoregional recurrence rates, disease-free survival rates, or overall survival rates.