Transanal vs laparoscopic total mesorectal excision for rectal cancer: a multicenter randomized phase III clinical trial (TaLaR trial) protocol

BACKGROUND: Total mesorectum excision (TME) is considered the standard surgical procedure for rectal-cancer treatment. Transanal TME (taTME) is a new procedure to treat low rectal cancer. Some published studies have proven that taTME can provide a better-quality resected specimen in low-rectal-cancer patients in comparison to the transabdominal procedure, yet long-term outcomes must be investigated. We designed this non-inferiority trial (TaLaR trial) to compare short-term and long-term outcomes between taTME and laparoscopic TME (lapTME) for rectal cancer. METHODS: The TaLaR trial is a phase III open-labeled multicenter randomized–controlled trial. Patients who are diagnosed with rectal cancer with no more than T3N2 stage, and with the tumor location below the peritoneal reflection by magnetic resonance imaging scan, digital rectal examination, or colonoscopy, qualify for this study. After calculating, a total of 1,114 patients (557 per group) will be randomly allocated to either the taTME or the lapTME group. Primary endpoints are the 3-year disease-free survival (DFS) rate and the 5-year overall survival (OS) rate. Secondary endpoints include specimen quality, perioperative results, pelvic and anal function, and quality of life. DISCUSSION: The TaLaR trial is expected to clarify whether taTME can achieve comparable oncological outcomes, as well as improve specimen quality and recovery conditions in rectal-cancer patients compared with lapTME.