Stoma Rate and Oncological Outcomes of Primary TaTME Vs Completion TaTME in Patients With Early-Stage Rectal Cancer

BACKGROUND: Local excision as a first step in the treatment of early rectal cancer has gained interest. However, in the presence of histopathological risk factors, (inter)national guidelines recommend completion total mesorectal excision. Although oncologically safe, completion total mesorectal excision is associated with an increased end colostomy rate compared to primary total mesorectal excision, especially in distal lesions. Transanal total mesorectal excision may facilitate lower anastomoses, potentially reducing end colostomy rates. OBJECTIVE: To compare the end colostomy rate and oncological outcomes of primary transanal total mesorectal excision with local excision followed by completion transanal total mesorectal excision in patients with cT1-2N0M0 rectal cancer. DESIGN: Data were prospectively collected and retrospectively analyzed. SETTINGS: This study was conducted in 6 Dutch high-volume centers experienced in transanal total mesorectal excision. PATIENTS: All patients with cT1-2N0M0 rectal cancer who underwent primary transanal total mesorectal excision or local excision followed by completion transanal total mesorectal excision between 2012 and 2022. MAIN OUTCOME MEASURES: The primary outcome was end colostomy rate. Secondary outcomes included anastomotic leakage, involvement of the circumferential resection margin, specimen quality, local recurrence, distant metastases, overall survival, and disease-free survival. RESULTS: A total of 150 patients were included with a median follow-up of 32 and 23 months for primary transanal total mesorectal excision and local excision followed by completion transanal total mesorectal excision, respectively. The end colostomy rate was significantly lower in the local excision followed by completion transanal total mesorectal excision group (21%) compared to the primary transanal total mesorectal excision group (42%, p = 0.022). More anastomotic leakages occurred in the local excision followed by completion transanal total mesorectal excision group (33% vs 18%, p = 0.064). No differences were observed in circumferential resection margin involvement and specimen quality. Two-year local recurrence rates were 4% for primary transanal total mesorectal excision and 3% for local excision followed by completion transanal total mesorectal excision (p = 0.343), whereas distant metastases occurred in 8% and 10% (p = 0.424), respectively. There were no significant differences in 2-year overall survival (88% vs 97%, p = 0.101) and 2-year disease-free survival (82% vs 90%, p = 0.463) between groups. LIMITATIONS: The small sample size, which precluded correction for group differences, and selection bias. CONCLUSIONS: This study demonstrated that local excision followed by completion transanal total mesorectal excision for cT1-2N0 rectal cancer neither increased the end colostomy rate nor compromised oncological outcomes compared to primary transanal total mesorectal excision in experienced centers.