Factors Predictive of Re-excision After Oncoplastic Breast-conserving Surgery.

Background: Oncoplastic surgery (OPS) consists of breast-conserving surgery (BCS) that allows for oncologically safe breast conservation and breast remodeling, thus reducing postoperative deformities. The purpose of the present study was to identify factors determining the risk of re-excision and complications after OPS. Patients and Methods: A retrospective analysis was conducted on patients who underwent OPS between 2009 and 2013, regardless of whether neoadjuvant chemotherapy was administered. Clinical and pathological factors were evaluated. Recursive partitioning analysis (RPA) was used to build regression trees for the prediction of re-excision. Results: Amongst the 129 patients treated by OPS procedures, 30.3% required re-excision. Predictive factors for re-excision were: being overweight (p=0.02), the presence of microcalcifications on mammography (p=0.003), and tumor multifocality (p=0.03). The RPA identified five terminal nodes based on microcalcifications on mammography, being overweight and the presence of ductal carcinoma in situ. Another model included minimal invasive margins (p<0.001), being overweight (p=0.02) and the presence of microcalcifications (p=0.01) on mammography yielded a model with an area under the receiver operating characteristic curve of 0.875. Conclusion: Microcalcifications, tumor multifocality and being overweight were the factors identified as predictors of re-excision after OPS. These factors can serve as decisional tools before surgery.