Triple-negative breast cancer is not a contraindication for breast conservation

Triple-negative breast cancer (TNBC) is an aggressive subtype shown to have a high risk of locoregional recurrence (LRR). The purpose of this study was to determine the impact of operation type on LRR in TNBC patients.

A total of 1325 patients with TNBC who underwent breast-conserving therapy (BCT) or mastectomy from 1980 to the present were identified. Clinical and pathological factors were compared by the chi-square test. LRR-free survival (LRRFS), distant metastasis-free survival, and overall survival were estimated by the Kaplan-Meier method. Multivariate analysis was performed by the Cox proportional hazard models.

BCT was performed in 651 patients (49%) and mastectomy in 674 (51%). The mastectomy group had larger tumors, a higher incidence of lymphovascular invasion, and higher pathologic N stage (all P < 0.001). At 62-month median follow-up, LRR was seen in 170 (26%) in the BCT group and 203 (30%) in the mastectomy group. Five-year LRRFS rates were higher in the BCT group (76% vs. 71%, P = 0.032), as was distant metastasis-free survival (68% vs. 54%, P < 0.0001) and overall survival (74% vs. 63%, P < 0.0001). On multivariate analysis, T stage (hazard ratio [HR] 1.37, P = 0.006), high nuclear grade (HR 1.92, P = 0.002), lymphovascular invasion (HR 1.93, P < 0.0001), close/positive margins (HR 1.89, P < 0.0001), and use of non-anthracycline or taxane-based adjuvant chemotherapy (HR 2.01, P < 0.0001) increased the LRR risk, while age >50 years was protective (HR 0.73, P = 0.007). Operation type (mastectomy vs. BCT, HR 1.07, P = 0.55) was not statistically significant.

BCT is not associated with increased LRR rates compared to mastectomy. TNBC should not be considered a contraindication for breast conservation.