Robotic Resection is a Good Prognostic Factor in Rectal Cancer Compared with Laparoscopic Resection: Long-term Survival Analysis Using Propensity Score Matching

Background: Robotic total mesorectal excision for rectal cancer has rapidly increased and has shown short-term outcomes comparable to conventional laparoscopic total mesorectal excision. However, data for long-term oncologic outcomes are limited. Objective: The aim of this study is to evaluate long-term oncologic outcomes of robotic total mesorectal excision compared with laparoscopic total mesorectal excision. Design: This was a retrospective study. Settings: This study was conducted in a tertiary referral hospital. Patients: A total of 732 patients who underwent totally robotic (n = 272) and laparoscopic (n = 460) total mesorectal excision for rectal cancer were included in this study. Main Outcome Measures: We compared clinicopathologic outcomes of patients. In addition, short- and long-term outcomes and prognostic factors for survival were evaluated in the matched robotic and laparoscopic total mesorectal excision groups (224 matched pairs by propensity score). Results: Before case matching, patients in the robotic group were younger, more likely to have undergone preoperative chemoradiation, and had a lower tumor location than those in the laparoscopic group. After case matching most clinicopathologic outcomes were similar between the groups, but operative time was longer and postoperative ileus was more frequent in the robotic group. In the matched patients excluding stage IV, the overall survival, cancer-specific survival, and disease-free survival were better in the robotic group, but did not reach statistical significance. The 5-year survival rates for robotic and laparoscopic total mesorectal excision were 90.5% and 78.0% for overall survival, 90.5% and 79.5% for cancer-specific survival, and 72.6% and 68.0% for disease-free survival. In multivariate analysis, robotic surgery was a significant prognostic factor for overall survival and cancer-specific survival (p = 0.0040, HR = 0.333; p = 0.0161, HR = 0.367). Limitations: This study has the potential for selection bias and limited generalizability. Conclusions: Robotic total mesorectal excision for rectal cancer showed long-term survival comparable to laparoscopic total mesorectal excision in this study. Robotic surgery was a good prognostic factor for overall survival and cancer-specific survival, suggesting potential oncologic benefits.