Is survival after transanal total mesorectal excision (taTME) worse than that after traditional total mesorectal excision? A retrospective propensity score-adjusted cohort study.

PURPOSE: Transanal total mesorectal excision (taTME) was developed to provide better vision during resection of the mesorectum. Conflicting results have shown an increase in local recurrence and shorter survival after taTME. This study compared the outcomes of taTME and abdominal (open, laparoscopic, robotic) total mesorectal excision (abTME).

METHODS: Patients who underwent taTME or abTME for stages I-III rectal cancer and who received an anastomosis were included. A retrospective analysis of a prospectively conducted database was performed. The primary endpoints were overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS). Risk factors were adjusted by propensity score matching (PSM). The secondary endpoints were local recurrence rates and combined poor pathological outcomes.

RESULTS: From 2012 to 2020, a total of 189 patients underwent taTME, and 119 underwent abTME; patients were followed up for a mean of 54.7 (SD 24.2) and 78.4 (SD 34.8) months, respectively (p < 0.001). The 5-year survival rates after taTME and abTME were not significantly different after PSM: OS: 78.2% vs. 88.6% (p = 0.073), CSS: 87.4% vs. 92.1% (p = 0.359), and DFS: 69.3% vs. 80.9% (p = 0.104), respectively. No difference in the local recurrence rate was observed (taTME, n = 10 (5.3%); abTME, n = 10 (8.4%); p = 0.280). Combined poor pathological outcomes were more frequent after abTME (n = 36, 34.3%) than after taTME (n = 35, 19.6%) (p = 0.006); this difference was nonsignificant according to multivariate analysis (p = 0.404).

CONCLUSION: taTME seems to be a good treatment option for patients with rectal cancer and is unlikely to significantly affect local recurrence or survival. However, further investigations concerning the latter are warranted.

TRIAL REGISTRATION: ClinicalTrials.gov (NCT0496910).