Factors predicting in-breast tumor recurrence after breast-conserving surgery

Purpose: The main objectives of this study were to identify risk factors for local in-breast tumor recurrence after breast-conservation and to evaluate the impact of IBTR (in-breast tumor recurrence) on overall survival. Methods: A total of 335 consecutive patients with 346 invasive and in situ breast cancers were treated with breast conserving therapy. Univariate and multivariate statistical analysis were performed and survival rates were calculated and analyzed using the Kaplan–Meier method. Results: With a median follow-up period of 70.6 months 14 patients (4%) developed an IBTR. Overall survival and the disease-free 8-year actuarial survival of patients were 95% and 93%, respectively. The overall survival of patients with tumour recurrence on any site was significantly shorter than of those without recurrence (64% versus 85% after 8 years of follow-up; P < 0.0001). Similarly, overall survival was significantly reduced in patients with distant metastases compared to all others without distant disease (88% versus 40% after 8 years; P < 0.0001). In contrast, overall survival of patients who experienced IBTR did not differ significantly from the group of patients who never developed IBTR (87% versus 70% after 8 years of follow-up). By univariate analysis, lobular carcinoma, high grade tumours, multifocality, concomitant LCIS and DCIS, the absence of estrogene and progesterone receptor status, as well as R1-status, were significant predictors of IBTR. By multivariate analysis, only R1-status (P < 0.002) and the presence of LCIS around the invasive tumour (P < 0.03) remained as significant factors predicting IBTR. Conclusions: Concomitant lobular carcinomas in situ, as well as R1 surgical status are independent significant risk factors for in breast tumor recurrence after breast conserving therapy.