Comparative study of surgical and oncological outcomes in oncoplastic versus non oncoplastic breast-conserving surgery for breast cancer treatment.

BACKGROUND: Oncoplastic surgery has been increasingly used in breast cancer treatment and allows the performance of breast-conserving surgery in cases of larger tumors with unfavorable location or tumor-breast disproportion. PURPOSE: To compare surgical and oncological outcomes of patients undergoing oncoplastic and nononcoplastic breast-conserving surgery. METHODS: Retrospective cohort study with convenience sampling of 866 patients who consecutively underwent breast-conserving surgery from 2011 to 2015. RESULTS: The mean follow-up was 50.4 months. Nononcoplastic breast conservation surgery was performed on 768 (88.7%) patients and oncoplastic surgery on 98 (11.3%) patients. Patients in the oncoplastic group were younger (p<0.0001) and most were premenopausal (p<0.0001). Comorbidities such as diabetes (p=0.003) and hypertension (p=0.0001) were less frequent in this population. Invasive carcinoma >2 cm (p<0.0001), multifocality (p=0.004), ductal in situ carcinoma (p=0.0007), clinically positive axilla (p=0.004), and greater weight of surgical specimens (p<0.0001) were more frequent in the oncoplastic group. A second surgery for margin re-excision was more frequently performed in the nononcoplastic group (p=0.027). There was more scar dehiscence in the oncoplastic group (p<0.001), but there was no difference in early major complications (p=0.854), conversion to mastectomy (p=0.92), or local recurrence (p=0.889). CONCLUSION: Although used for the treatment of larger and multifocal tumors, surgical re-excisions were performed less often in the oncoplastic group, and there was no increase in conversion to mastectomy or local recurrence. In spite of the higher rate of overall complications in the oncoplastic group, major complications were similar in both groups.