Three-year disease-free survival after transanal vs. laparoscopic total mesorectal excision for rectal cancer (TaLaR): A randomized clinical trial.

3516 Background: Transanal total mesorectal excision (taTME) has gained significant traction as an effective approach for treating rectal cancer. Many previous studies reported positive relevant short-term results, histopathological results and associated complications of taTME compared to laparoscopic total mesorectal excision (laTME). Nonetheless, long-term oncological outcomes of taTME remain controversial. This study aimed to compare the 3-year DFS of taTME with laTME. Methods: We conducted a phase 3, randomized, open-label, noninferiority trial to compare the survival outcomes of taTME versus laTME in patients with rectal cancer located below the peritoneal reflection. This trial encompassed 16 hospitals across 10 provinces in China, with a total enrollment of 1,115 patients. We set the 3-year disease-free survival (DFS) and 5-year overall survival (OS) as the primary endpoints for analysis. The analysis of the 3-year DFS was conducted following a predefined modified intention-to-treat principle. This study is registered with ClinicalTrials.gov, number NCT02966483. Results: The taTME group exhibited a 3-year DFS rate of 83.42%, and the laTME group achieved a 3-year DFS rate of 82.86%. The marginal difference of 0.56% between the DFS rates of the two groups (97.5% CI, −4.83 to 5.95, P < 0.0001 for noninferiority) suggests comparable outcomes. Moreover, the rates of local recurrence were 3.90% in the taTME group and 3.62% in the laTME group, indicating similar degrees of localized tumor control. Regarding overall survival, the taTME group demonstrated a rate of 94.50% compared to 92.01% in the laTME group. In the taTME group, patients who are male or underwent neoadjuvant showed a higher 3-year OS than that in the laTME group. Conclusions: In patients with mid-low rectal cancer, the 3-year DFS of taTME is not inferior to that of laTME. This study provides evidence supporting the clinical effectiveness of taTME in the treatment of rectal cancer. Clinical trial information: NCT02966483 .