Robotic versus laparoscopic surgery for middle and low rectal cancer: a retrospective cohort study emulating the target trial

BACKGROUND: Robotic surgery for rectal cancer is popular, but persuasive evidence of long-term oncological outcomes in real-world populations is still lacking. MATERIALS AND METHODS: This retrospective cohort study emulated the target trial to compare surgical quality and long-term oncological outcomes between robotic and conventional laparoscopic surgery for middle and low rectal cancer in real-world populations. Patients were consecutively enrolled from a multicenter cohort database in Shanghai, China, with middle or low rectal adenocarcinoma, cT1-T3 N0-N1 or ycT1-T3 Nx, no distant metastasis. Eligible patients were classified into robotic or laparoscopic groups and propensity score matched at a 1:1 ratio. The primary endpoint was 3-year disease-free survival rate. RESULTS: From 3742 eligible patients, 2702 were included in primary analyses after matching: 1351 in robotic group and 1351 in laparoscopic group. The median follow-up time was 42.4 months (interquartile range = 39.5-45.3). The robotic group had higher 3-year disease-free survival rate (86.7% vs. 83.3%, p = 0.017, unadjusted hazard ratio [HR] = 0.800, 95% confidence interval [CI] = 0.666-0.961, adjusted HR = 0.786, 95% CI = 0.654-0.945). The robotic group also had lower 3-year locoregional recurrence rate (2.2% vs. 4.7%, p = 0.001), lower 30-day postoperative complication rate (14.3% vs. 19.5%, p < 0.001), lower abdominoperineal resection rate (7.5% vs. 12.4%, p < 0.001), and lower circumferential resection margin positivity rate (2.2% vs. 4.2%, p = 0.005). No significant difference in 3-year overall survival rate was observed (96.4% vs. 95.5%, p = 0.063). CONCLUSIONS: Compared with conventional laparoscopic surgery, robotic surgery significantly improved long-term oncological outcomes and short-term recovery of middle and low rectal cancer in real-world populations.