Comparison of the Safety and Aesthetic Outcomes of a Novel Endoscopic-Assisted Breast-Conserving Surgery (SRRSHzb-EABCS) With Those of Conventional Breast-Conserving Surgery

Conditions studied

Breast Cancer

About this study

This multicenter, open-label, prospective, randomized controlled study compares a novel endoscopy-assisted breast-conserving surgery technique (SRRSHzb-EABCS) with conventional open breast-conserving surgery (CBCS) in women with breast cancer who wish to preserve their breast. Breast-conserving surgery followed by radiotherapy is a standard treatment for early-stage breast cancer. Conventional open surgery leaves visible scars on the breast, while traditional endoscopy-assisted techniques are time-consuming, difficult to learn, and costly. The investigators developed a novel technique, SRRSHzb-EABCS, which uses a gasless expansion-traction endoscopic system with a custom-built skin flap dissector and V-shaped retractor, together with percutaneous U-shaped metal wires placed around the marked tumor margin, enabling precise tumor localization and margin control through a single axillary incision. The technique is designed to be easier to learn, shorter in operative time, less expensive, and more cosmetic. Eligible participants are randomly assigned in a 1:1 ratio to undergo either SRRSHzb-EABCS or conventional open breast-conserving surgery. The main goal of the study is to compare the intraoperative and postoperative positive margin rates between the two techniques. The study also compares aesthetic outcomes measured by BREAST-Q scores at 1 and 18 months after surgery, complication rates, and 5-year local recurrence, disease-free survival, and overall survival. A total of 422 participants (211 per arm) will be enrolled at Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, and multiple participating centers in China. Participants are followed at 1 month and 18 months after surgery, with long-term follow-up for up to 5 years.

Interventions

• Procedure: Endoscopy-assisted breast-conserving surgery (SRRSHzb-EABCS) — A novel gasless endoscopy-assisted breast-conserving surgery using an expansion-traction system (a skin flap dissector and a V-shaped retractor) and a metal wire-based tumor localization system. Through a single 3.0-4.5 cm axillary incision, the retromammary space is created endoscopically. The resection margin is marked 1.5-2.0 cm beyond the tumor edge; U-shaped cutting wires and marking wires are placed percutaneously. The flap is dissected while the V-shaped retractor maintains the working space. Each cutting wire is energized with an electrocautery pencil to cut along the planned margin ("hot-wire" cutting). Margins are assessed by frozen section; positive margins undergo local re-excision, and repeatedly positive margins lead to mastectomy. Axillary management: sentinel lymph node biopsy (SLNB) for clinically node-negative patients, with axillary lymph node dissection (ALND) performed according to biopsy results; clinically node-positive patients undergo ALND directly.
• Procedure: Conventional open breast-conserving surgery (CBCS) — Conventional open breast-conserving surgery performed according to the Chinese Anti-Cancer Association guidelines for breast-conserving therapy. Generally, separate incisions are made on the breast and in the axilla. The resection includes the tumor together with a margin of surrounding breast tissue. Specimen margins are marked and assessed (inking and/or intraoperative frozen section). Four to six titanium clips are placed in the tumor bed for radiation boost localization. Oncoplastic volume displacement or volume replacement techniques are applied when needed. If a margin is positive on intraoperative or postoperative pathology, local re-excision of the margin is performed, and if margins remain repeatedly positive, mastectomy is performed. Axillary management: sentinel lymph node biopsy (SLNB) for clinically node-negative patients, with axillary lymph node dissection (ALND) performed according to biopsy results; clinically node-positive patients undergo ALND directly.

Primary outcomes

• Intraoperative and Postoperative Positive Margin Rate (Intraoperatively and up to 1 month after surgery (final pathology report))