Abstract
BACKGROUND: Breast-conserving surgery (BCS) is a widely used alternative to mastectomy for early-stage breast cancer. Achieving clear surgical margins is critical to reducing local recurrence, but re-excision is sometimes required, potentially delaying adjuvant therapy and affecting outcomes. Data on trends, predictors, and implications of re-excision in Saudi Arabia are limited. METHODS: We conducted a retrospective cohort study of 1,248 women who underwent BCS for invasive breast cancer or ductal carcinoma in situ at tertiary hospitals in the Eastern Province from 2015 to 2024. Patient demographics, tumor characteristics, surgical details, margin status, and adjuvant therapy timelines were collected. The primary outcome was re-excision, defined as any subsequent breast operation to achieve negative margins. Univariable and multivariable logistic regression analyses were performed to identify predictors of re-excision. Temporal trends in re-excision rates and time to adjuvant therapy were analyzed. RESULTS: The median patient age was 54 years (interquartile range (IQR): 46-63), and invasive ductal carcinoma was the most common histology (78.6%). Overall, 181 (14.5%) patients underwent re-excision, with rates declining from 18.6% in 2015 to 11.2% in 2024. Positive margin status at the index surgery was the strongest predictor of re-excision (adjusted odds ratio (OR): 4.52; 95% confidence interval (CI): 3.15-6.47). Other independent predictors included younger age (<45 years; OR: 1.82), lobular histology (OR: 1.94), tumor size > 2 cm (OR: 1.73), and multifocal disease (OR: 2.06). Preoperative MRI was associated with reduced odds of re-excision (OR: 0.66). Median time from index surgery to final margin clearance was 18 days for patients undergoing re-excision. Delays in radiotherapy beyond eight weeks occurred in 41.6% of re-excised patients versus 19.3% without re-excision (P<0.001). Three-year local recurrence did not differ significantly between groups (4.1% versus 2.7%; P=0.11). CONCLUSIONS: Re-excision rates after BCS in Saudi Arabia have declined over the past decade. Positive margin status, younger age, lobular histology, larger tumors, and multifocal disease remain key risk factors. Re-excision is associated with delays in adjuvant radiotherapy, highlighting the importance of strategies to minimize repeat surgery while ensuring oncologic safety.