Breast-conserving surgery is not associated with increased local recurrence in patients with early-stage node-negative triple-negative breast cancer treated with neoadjuvant chemotherapy

Background: Neoadjuvant chemotherapy (NACT) is routinely used for patients with triple-negative breast cancer (TNBC). Upfront breast-conserving therapy (BCT) consisting of breast-conserving surgery (BCS) and adjuvant radiotherapy (RT) has been shown to be associated with improved outcome in patients with early TNBC as compared to mastectomy. Methods: We identified 2632 patients with early TNBC from the German Breast Group meta-database. Patients with cT1-2 cN0 and ypN0, available surgery and follow-up data were enrolled. Data of 1074 patients from 8 prospective NACT trials were available. Endpoints of interest were locoregional recurrence as first site of relapse (LRR), disease-free survival (DFS) and overall survival (OS). We performed univariate and multivariate Fine-Gray analysis and Cox regression models. Results: After a median follow-up of 64 months, there were 94 (8.8%) locoregional events as first site of relapse. Absence of pathologic complete response (pCR) was associated with increased LRR upon uni- and multivariate analysis (hazard ratio [HR] = 2.28; p