Reoperation rate after breast conserving surgery as quality indicator in breast cancer treatment: A reappraisal

Aim: To analyse the role of repeated breast surgery (RBS) after breast conserving surgery (BCS) as a quality indicator in a consecutive series of breast cancer patients. Methods: Data from 1233 breast cancer patients submitted to BCS from 2015 to 2019 were reviewed. The influence of several variables on RBS rate (182/1232; 14.8%) was examined. Univariate and multivariate analyses were conducted to look for significant associations with the risk of RBS. Results: Surgical workload, BCS rate and clinicopathological variables were consistent over the study period, while RBS rate decreased after the introduction of shaving of cavity margins (from 17.9% to 9.5%). Tumor persistence at RBS was higher for mastectomy vs. re-excision (87.3% vs. 37.8%; p = 0.05), inconclusive vs. positive diagnostic biopsy (48.2% vs. 69.4%; p = 0.003), ductal carcinoma in situ vs. invasive carcinoma (69.0% vs. 51.3%; p = 0.046) and lower after neoadjuvant therapy (14.3% vs. 57.8%; p = 0.044). Several clinicopathological variables were associated with the risk of RBS, but only multifocality [Odds Ratio (OR): 1.8; p = 0.009], microcalcifications (OR: 2.0, p = 0.000), neoadjuvant therapy (OR: 0.4; p = 0.014), pathological intraoperative assessment (OR: 0.6; p = 0.010) and shaving of cavity margins (OR: 0.3; p = 0.000) retained independent value at multivariate analysis. Conclusions: RBS rate can be reduced by shaving of cavity margins. Current standards for RBS should not be made more stringent due to the existence of non-actionable risk factors. The value of RBS as a quality indicator should be scrutinzed.