Predictors of re-excision for positive or close margins in breast-conservation therapy for pT1 tumors

Background An increasing number of patients with early-stage breast cancer is being diagnosed by way of population-wide mammographic screening in women. Because breast-conservation therapy (BCT) is the standard treatment, the aim of our study was to determine factors predisposing patients to re-excision for pT1 tumors. Methods A retrospective study was conducted at Besancon University Hospital in France. Patients with pathologic diagnosis of invasive breast carcinoma <20 mm in size (pT1) and undergoing BCT were selected. From these, “no–re-excision” and “re-excision” subgroups were constituted and compared in terms of patient and tumor characteristics. The intent of all surgeries was therapeutic. Results Of 206 patients who underwent BCT for pT1 tumors, 84 (41%) needed re-excision. After multivariate analysis, factors predicting re-excision were the absence of positive histologic diagnosis before surgery (P <.0001), limited superficial and deep surgical resection (P <.0001), multifocal lesion (P <.0001), and size of the in situ carcinoma (P <.0001). Conclusions These predictive factors could be useful in reducing the rate of re-excision as well as in identifying patients with multifocal tumors and/or extensive in situ carcinoma whose disease would be better managed by mastectomy.