Association of Adjuvant Radiotherapy De‐Escalation With Outcomes Following Oncoplastic Breast‐Conserving Surgery

BACKGROUND: Adjuvant radiotherapy (RT) following breast-conserving surgery reduces local recurrence but can introduce reconstructive morbidity. Although recent trials support the safe omission of RT in selected patients, its impact on surgical and patient-reported outcomes following oncoplastic breast-conserving surgery (OPBCS) remains poorly defined. We evaluated surgical and long-term patient-reported outcomes in patients undergoing OPBCS, stratified by receipt of RT. METHODS: We retrospectively studied consecutive patients who underwent OPBCS between 2017 and 2024 for stage 0-3 breast cancer. Patients were stratified based on receipt of RT. Postoperative complications, unplanned reoperation, and revision procedures were compared between cohorts. Long-term patient-reported outcomes were assessed using the validated BREAST-Q Reconstruction Module. Multivariable regression was used to evaluate the independent association between RT status and outcomes. RESULTS: We identified 257 patients; 210 patients received RT (81.7%) and 47 underwent RT de-escalation (18.3%). Surgical site infection (p = 0.100), delayed wound healing (p = 0.300), and skin flap necrosis rates (p = 0.0300) were similar between cohorts. Seroma (30% vs. 13%; p = 0.006) and unplanned reoperation (21% vs. 7.1%; p = 0.006) were more frequent with RT omission. Patients who did not receive RT demonstrated significantly higher mean Satisfaction with Breasts scores compared with those who received RT (57 ± 25 vs. 23 ± 24; p = 0.001). In adjusted models, RT de-escalation was associated with a 36-point increase in Satisfaction with Breasts scores (β = 36.0; 95% CI, 18.0-54.0; p < 0.001). CONCLUSIONS: RT omission was independently associated with higher patient-reported satisfaction with breasts, though patients had higher seroma and reoperation rates. These data support balanced shared decision-making for RT de-escalation in appropriately selected patients.