A randomized clinical trial comparing transanal and laparoscopic total mesorectal excision found no statistically significant difference in 3-year disease-free survival among patients with stage I to III mid-low rectal cancer.

Conducted across 16 centers in China, the TaLaR trial, published in JAMA, supported the use of transanal mesorectal excision (TME) as a viable surgical option. Between April 2016 and June 2021, 1,115 patients were randomly assigned 1:1 to undergo either transanal TME (n = 558) or laparoscopic TME (n = 557). The median age of participants was 60 years, with 692 male and 397 female patients included in the primary analysis. 

The patients in the transanal TME group achieved a 3-year disease-free survival rate of 82.1% (97.5% confidence interval [CI] = 78.4%–85.8%) compared with 79.4% (97.5% CI = 75.6%–83.4%) among the patients in the laparoscopic TME group. The difference of 2.7% (97.5% CI = –3.0% to 8.1%) met the predefined noninferiority margin of –10 percentage points.

Among the key findings were:

• Disease-Free Survival: transanal TME: 82.1%; laparoscopic TME: 79.4%
• Local Recurrence: transanal TME: 3.6% (95% CI = 2.0%–5.1%); laparoscopic TME: 4.4% (95% CI = –6.1%)
• Overall Survival: transanal TME: 92.6% (95% CI = 90.4%–94.8%); laparoscopic TME: 90.7% (95% CI = 88.3%–93.2%).

The trial demonstrated that the lower bound of the confidence interval for the difference in 3-year disease-free survival remained above the noninferiority threshold, supporting the clinical equivalence of transanal TME and laparoscopic TME in terms of long-term oncologic outcomes.

"Transanal TME is likely to continue being promoted as an alternative treatment for rectal cancer in areas where expertise in surgical robotic techniques is not available," explained lead study author Ziwei Zeng, MD, of the Department of General Surgery (Colorectal Surgery) at the Sun Yat-sen University in Guangzhou, Guangdong, China, and colleagues.

The researchers emphasized the need for continued investigation into long-term outcomes and the integration of transanal TME techniques into clinical practice.

The trial offered valuable insights for clinicians evaluating surgical options for rectal cancer, providing evidence that transanal TME may offer comparable oncologic outcomes to laparoscopic techniques.

The study authors disclosed no conflicts of interest.