Comparison of Short-term and Three-year Oncological Outcomes between Robotic and Laparoscopic Gastrectomy for Gastric Cancer: A Large Multicenter Cohort Study

Objective: To compare the short-term and long-term outcomes between robotic gastrectomy (RG) and laparoscopic gastrectomy (LG) for gastric cancer. Background: The clinical outcomes of RG over LG have not yet been effectively demonstrated. Methods: This retrospective cohort study included 3599 patients with gastric cancer who underwent radical gastrectomy at eight high-volume hospitals in China from January 2015 to June 2019. Propensity score matching was performed between patients who received RG and LG. The primary end point was 3-year disease-free survival (DFS). Results: After 1:1 propensity score matching, 1034 pairs of patients were enrolled in a balanced cohort for further analysis. The 3-year DFS in the RG and LG was 83.7% and 83.1% (P=0.745), respectively, and the 3-year overall survival was 85.2% and 84.4%, respectively (P=0.647). During 3 years of follow-up, 154 patients in the RG and LG groups relapsed (cumulative incidence of recurrence: 15.0% vs 15.0%, P=0.988). There was no significant difference in the recurrence sites between the 2 groups (all P>0.05). Sensitivity analysis showed that RG had comparable 3-year DFS (77.4% vs 76.7%, P=0.745) and overall survival (79.7% vs 78.4%, P=0.577) to LG in patients with advanced (pathologic T2-4a) disease, and the recurrence pattern within 3 years was also similar between the 2 groups (all P>0.05). RG had less intraoperative blood loss, lower conversion rate, and shorter hospital stays than LG (all P>0.05). Conclusions: For resectable gastric cancer, including advanced cases, RG is a safe approach with comparable 3-year oncological outcomes to LG when performed by experienced surgeons.