Comparison of short- and long-term outcomes of robotic vs. laparoscopic gastrectomy for clinical serosa-invasive gastric cancer: A multicenter cohort study

Objective: Robotic gastrectomy (RG) is increasingly used in the treatment of gastric cancer. However, studies on patients with clinical serosa-invasive (cT4a) gastric cancer remain scarce. This study aimed to compare the short- and long-term outcomes of RG and laparoscopic gastrectomy (LG) in the treatment of stage cT4a gastric cancer. Methods: A retrospective analysis was conducted on the clinical data of patients with stage cT4a gastric cancer diagnosed and treated at eight high-volume tertiary teaching hospitals in China from 2016 to 2019. Propensity score matching (PSM) analysis and inverse probability of treatment weighting (IPTW) analysis was used to adjust for the imbalance in baseline characteristics. The primary research endpoint was the 3-year overall survival (OS) and disease-free survival (DFS). The secondary research endpoint was intraoperative outcomes and postoperative complications. Results: After IPTW and PSM adjustments, baseline characteristics between the RG and LG groups were comparable [standardized mean difference (SMD) <0.10]. Post-PSM analysis revealed that the RG group exhibited longer operative time (P<0.001), lower postoperative complication rates (P<0.001), shorter postoperative hospital stays (P=0.037), and earlier initiation of adjuvant chemotherapy (P=0.041) compared with the LG group. Survival analysis demonstrated comparable 3-year OS (P=0.110) and DFS (P=0.088) in the PSM cohort, whereas the IPTW cohort showed superior OS (P=0.030) and DFS (P=0.046) for RG. No significant differences were observed in overall recurrence rates or recurrence sites between groups. Conclusions: For patients with stage cT4a gastric cancer, compared with the LG group, the RG group had shorter postoperative hospital stay, lower incidence of postoperative complications, earlier postoperative adjuvant chemotherapy, and no worse long-term efficacy.