Pushing the Limits of Breast-Conserving Surgery with Extreme Oncoplasty.

Introduction: We aimed to report the long-term surgical outcomes of extreme oncoplasty techniques in selected patients with unifocal (UF)/cT3 or multifocal-multicentric tumors (MFMC). Material and Methods: Patients who were initially recommended to have mastectomy underwent extreme oncoplastic breast-conserving surgery (eOBCS) including therapeutic reduction mammoplasty, racquet, and round-block mammoplasty, Grisotti flap, or combined technique were included. Preoperative tumor parameters, clinical outcomes, rate of local recurrence, survival, and patients' satisfaction were assessed. Results: Eighty-six patients with a median age of 51 years were followed for a median follow-up of 75 (8-154) months; 31 (36%) had cT3 and 55 (64%) had MFMC tumors. The majority of patients (83.6%) had invasive cancer. The median UF tumor size was 58 mm (range 51-100) on imaging and 51 mm (range 50-60) on final pathology. The median tumor span for MFMC was 65 mm (range 53-95) on imaging, whereas the median of the largest tumor size was 30 mm (range 22-60) on final pathology. Seventy-one patients (82.5%) were ER-positive, 17 (19.7%) were HER2 positive, and 8 (9.3%) were triple-negative breast cancer. Four patients (4.7%) required further intervention for having positive margins (3 re-excisions, 1 completion mastectomy). Three local recurrences (3.4%) and 10 (11.6%) distant metastasis occurred. The cosmetic outcome was excellent in 37 (43%) patients. No major complications were observed. Conclusions: eOBCS can be a good option for patients who initially require mastectomy. Appropriate patient selection, a multidisciplinary approach, and patient consent are essential steps of the procedure.