The Comparison Between M-E-BCS and C-O-BCS.

Breast cancer is a highly prevalent malignant tumor among women, and comprehensive treatment mainly based on surgery is the main mode. Breast aesthetics is important, breast-conserving surgery (BCS) is a common surgical approach, which can preserve the breast shape, does not affect subsequent treatment, and has been confirmed to be safe in terms of oncology. Conventional open breast-conserving surgery (C-O-BCS) requires multiple incisions, resulting in prominent scars. With the introduction of minimally invasive techniques, endoscopic breast-conserving surgery (E-BCS) has emerged as an alternative. It reduces the number of incisions, lowers the incidence of complications, and enhances aesthetic outcomes and patient satisfaction, while maintaining similar oncological safety compared to open surgery. However, single-incision E-BCS is limited by restricted operative space, making precise tumor resection and oncoplastic procedures challenging. Although multi-incision E-BCS facilitates surgical procedures, it does not improve scar aesthetics and may increase surgical trauma and costs. As a result, the adoption of endoscopic breast-conserving surgery has been limited, and there is a lack of high-quality clinical studies in this area. Our team proposed the minimal accessory-incision-assisted endoscopic breast-conserving surgery (M-E-BCS), which has concealed incisions, strong operability, and good cosmetic effects. It is being popularized in China. To comprehensively evaluate its clinical benefits, large-scale multicenter studies are needed to provide evidence-based medical evidence and optimize surgical plans. Therefore, this national multicenter, open-label, randomized controlled trial will compare outcomes between patients undergoing M-E-BCS versus C-O-BCS. The study aims to evaluate differences in operative efficiency (e.g., operative time), economic effect, surgical safety (e.g., surgical complication rates), postoperative aesthetics (e.g., BREAST-Q scores, Harris scores, SCAR-Q scores and Ueda scores), and oncological safety (e.g., margin status, no local recurrence survival).