Reoperation rates following breast-conserving surgery in a contemporary cohort

Breast-conserving surgery (BCS) followed by adjuvant radiotherapy is the standard of care for early-stage breast cancer. However, reoperations after BCS may compromise aesthetic outcomes, increase surgical complications, and cause psychological distress. This study aimed to determine the reoperation rate after BCS in a multi-institutional cohort from Brazil and to identify predictive factors associated with reoperation. This retrospective multicenter cohort study included female breast cancer patients (AJCC clinical stage 0–III) who underwent BCS followed by adjuvant radiotherapy at six treatment centers in Brazil between January 2016 and December 2022. Logistic regression was used to assess the association between potential risk factors and reoperation. The overall reoperation rate was 5.2%, with a higher rate in the public hospital (9.9%) than in private hospitals (4.8%). Patients had a mean age of 58.2 years, with 70.5% aged over 50; 58.3% were White, and 89.8% were treated in private settings. The most common histological type was invasive ductal carcinoma (67.0%), with AJCC stage I (49.3%) and hormone receptor–positive tumors (54.6%) predominating. Logistic regression showed that ductal carcinoma in situ (DCIS) was significantly associated with an increased risk of reoperation (OR 2.59, 95% CI 1.08–5.76, p = 0.024), whereas the absence of multifocal tumors was associated with a reduced risk (OR 0.37, 95% CI 0.16–0.98, p = 0.031). Reoperation after BCS was infrequent in this cohort. DCIS was associated with an increased risk of reoperation, whereas the absence of multifocal disease was associated with a reduced risk. Higher reoperation rates observed in the public hospital should be interpreted with caution given the limited representation of this setting.