Analysis of factors affecting aesthetic outcomes and safety in breast-conserving surgery: A multicentre prospective cohort study.

e12569 Background: Breast conservation surgery (BCS) has gradually become the mainstream surgical approach for breast cancer; however, few studies have explored which factors influence the aesthetic outcome, complications, and tumor safety after BCS. This study aims to compare the factors affecting the aesthetics and safety of breast conservation surgery in a multicenter prospective breast cancer cohort. Methods: Women from a prospective, multicenter breast cancer cohort who underwent BCS were included. Aesthetic scores (AIS and Breast-Q scores) were evaluated at 1, 3, 6, and 12 months postoperatively, and various postoperative complications, perioperative parameters such as margins, and long-term follow-up indicators including disease-free survival (DFS), overall survival (OS), and recurrence-free survival (RFS) were also assessed. Results: A total of 701 individuals were ultimately included in the study, with a median follow-up time of 30.5 month. Among them, 398 (56.8%) underwent single-port non-liposuction endoscopic surgery, 401 (57.2%) had areolar incisions, and 405 (57.7%) had tumors located more than 2 cm from the nipple. Our findings revealed that non-endoscopic surgery and non-circumareolar incision provided worse breast aesthetic outcomes compared to endoscopic groups (12 months-AIS [effect size: -1.34; 95% CI: -1.70 to -0.99]) and circumareolar incision(12 months-AIS [effect size: -1.20; 95% CI: -0.55 to -1.86]), as well as similar postoperative complications, recurrence, and survival. Additionally, tumors located farther from the nipple (12 months-AIS [effect size: 0.44; 95% CI: 0.09 to 0.80]) also demonstrated better aesthetic outcomes and comparable safety profiles. Conclusions: Endoscopic breast-conserving surgery and areolar incisions can increase postoperative breast aesthetics and patient satisfaction without compromising complications and oncological safety, providing guidance for clinical decision-making. Clinical trial information: ChiCTR2100043403 .