Long-term oncological outcomes of transanal versus laparoscopic total mesorectal excision for mid-low rectal cancer: a retrospective analysis of 2502 patients

Abstract

Background: Transanal total mesorectal resection (taTME) has recently emerged as a promising surgical approach for the treatment of mid-low rectal cancer. However, there is limited evidence on the long-term survival outcomes associated with taTME. This retrospective study aimed to compare the overall survival (OS), disease-free survival (DFS), and cancer-specific survival of taTME and laparoscopic TME (laTME) in patients with mid-low rectal cancer. Materials and Methods: From July 2014 to June 2022, a total of 3,672 patients were identified from two prospective cohorts: the laparoscopic rectal surgery cohort and the CNTAES cohort. To balance the baseline characteristics between the taTME and laTME groups, propensity score matching (PSM) was performed. Results: A total of 2,502 patients were included in the study. Prior to PSM, the laTME group comprised 1,853 patients, while the taTME group comprised 649 patients. The 5-year OS (82.9% vs. 80.4%, P=0.202) and 5-year DFS (74.4% vs. 72.5%, P=0.167) were comparable between the taTME and laTME groups. After PSM, the taTME group showed no statistically significant difference in the 5-year OS (83.1% vs. 79.2%, P=0.101) and 5-year DFS (74.8% vs. 72.1%, P=0.135) compared to the laTME group. Subgroup analysis further suggested that taTME may potentially reduce the risk of death (HR 0.652; [95% CI, 0.452-0.939]) and disease recurrence (HR 0.736; [95% CI, 0.562-0.965]) specifically in patients with low rectal cancer. Conclusion: In our study, taTME demonstrated comparable oncologic safety to laTME in patients with mid-low rectal cancer. Moreover, the results indicate that taTME may confer potential survival benefits for patients with low rectal cancer.