[Chinese expert consensus for resection margin in rectal cancer surgery (2024 edition)]

Colorectal cancer is the second most common malignant tumor in China, with rectal cancer accounting for approximately 50% of all cases. While neoadjuvant therapy is essential for diagnosis and treatment, proctectomy with radical resection remains indispensable. Especially for middle and low rectal cancer, the length of the distal resection margin is critical for prognosis, organ preservation, and postoperative quality of life. However, determining a "safe" margin to ensure the radical resection (R0) while maximizing the function of the anal sphincter poses a significant challenge for surgeons. Aiming at this, we conducted a comprehensive review of authoritative guidelines and literature domestically and internationally. We divided the issues related to resection margin in proctectomy into three chapters: (1) the concept and definition of the resection margin; (2) the evaluation of the resection margin in preoperative, intra-operative, and post-operative stages; and (3) radical resection of rectal cancer after neoadjuvant therapy. With the help of the Delphi method, the expert group voted twice for 14 recommendations and finally established the "Chinese Expert Consensus for Resection Margin in Rectal Cancer Surgery (2024 version)". This consensus serves as a valuable reference for clinicians to carry out proctectomy of rectal cancer, which can improve patient's quality of life without affecting their prognosis.