Comparative Oncologic Outcomes of Laparoscopic versus Open Surgery for Early-Onset Low Rectal Cancer: 3-Year Results From the LASRE Trial.

Abstract

Low rectal cancer poses unique surgical challenges due to its anatomy, complicating the balance between radical resection and functional preservation. Early-onset low rectal cancer (EO-LRC, < 50 years) adds complexity: it has distinct, more aggressive biological/clinical features but no age-stratified surgical guidelines. Moreover, laparoscopic surgery's efficacy in EO-LRC is controversial-though non-inferior in general low rectal cancer, EO-LRC's aggressiveness may offset its benefits. This study aims to compare oncologic outcomes of laparoscopic versus open surgery in EO-LRC patients. In this post-hoc analysis of the LASRE trial, the cohort included 240 EO-LRC and 799 late-onset low rectal cancer (LO-LRC, ≥ 50 years) patients, and were randomly assigned to open or laparoscopic resection. Primary endpoints were 3-year overall survival (OS) and disease-free survival (DFS). EO-LRC exhibited better ECOG performance status and lower ASA scores; however, they presented with more advanced disease and received more preoperative therapy. The operative time and blood loss were comparable. EO-LRC patients had a higher proportion of pN2 stage and poorly differentiated tumors. The total mesorectal excision quality and negative margins were similar. The 3-year OS (laparoscopic 91.3% vs. open 95.5%, p = 0.270) and DFS (laparoscopic 78.6% vs. open 76.1%, p = 0.657) were comparable between groups. Multivariate analysis identified preoperative therapy and pN classification as significant prognostic factors for DFS. No significant differences in oncologic outcomes were observed between groups. Laparoscopic TME provides non-inferior oncologic control in EO-LRC patients. The small EO-LRC sample size necessitates cautious interpretation of findings, requiring validation in larger cohorts.