Comparison of Long-Term Ontological Outcomes in Oncoplastic Breast Surgery and Conventional Breast-Conserving Surgery for Breast Cancer: A Propensity Score-Matched Analysis

Purpose: The oncoplastic breast-conserving surgery (OPS) technique, combined with the principles of oncological safety and plastic surgery, results in complete tumor resection while preserving the natural appearance of the breast. The purpose of this study was to evaluate the long-term oncological results after OPS compared with conventional breast-conserving surgery (BCS) for early breast cancer. Methods: The medical records of patients who underwent breast cancer surgery and adjuvant radiation therapy at Seoul National University Hospital between 2011 and 2014 were reviewed. Ipsilateral breast tumor recurrence (IBTR)-free survival rate and recurrence-free survival (RFS) rates were compared between the OPS and BCS groups. Results: One-to-one propensity score matching was conducted, yielding 371 patients in each group. The mean tumor distance from the nipple was shorter, and the mean retrieved specimen size and pathologic tumor size, including ductal carcinoma in situ, were larger in the OPS group than in the conventional BCS group (p < 0.001). Surgical margin positivity was not significantly different between the two groups (p= 0.777). The surgical technique was not significantly associated with IBTR (OPS versus conventional BCS, 5-year survival rate, 96.9% vs. 98.6%; p= 0.355) and RFS (5-year survival rate, 92.9% vs. 94.5%; p = 0.357) on the log-rank test. Multivariate analysis revealed that OPS versus conventional BCS was not significantly associated with survival outcomes. Conclusion: We observed no significant differences in long-term IBTR and RFS between the OPS and conventional BCS groups in this retrospective analysis. OPS can be an ontologically and surgically safe alternative option for conventional BCS for early breast cancer.