Comparison of surgical and oncological outcomes between oncoplastic breast-conserving surgery versus conventional breast-conserving surgery for treatment of breast cancer: A systematic review and meta-analysis of 31 studies

Aims: To evaluate comparative outcomes of oncoplastic breast conserving surgery (OBCS) versus conventional breast conserving surgery (BCS) for breast cancer treatment. Methods: A systematic search of multiple electronic data sources was conducted, and all eligible studies comparing OBCS and BCS were included. Characteristics of the tumour includes preoperative size of tumour on imaging and the weight of the specimen after resection. While positive margins rate, re-excision rate, completion mastectomy rate and loco-regional recurrence were considered as oncological outcome parameters. Post-operative complications include surgical site infection (SSI), seroma, haematoma and skin/nipple necrosis. Results: Thirty-one studies reporting a total number of 115011 patients who underwent OBCS (n = 11978) or BCS (n = 103033) were included. OBCS group showed lower risk of positive margins rate [OR 0.76, P = 0.05], re-excision rate [OR 0.72, P = 0.02], and loco-regional recurrence [OR 0.62, P = 0.03] compared to BCS group. There was no significant difference between the two groups regarding post-operative complications. Conclusion: Although there is a lack of level 1 evidence, the available studies clearly demonstrate superior or at least equivalent outcomes when comparing OBCS with conventional BCS. The benefits of OBCS include dealing with larger tumours, wider surgical margins and better aesthetic results for patients.