Robotic versus laparoscopic distal gastrectomy for resectable gastric cancer: a randomized phase 2 trial

Abstract

Robotic surgery may be an alternative to laparoscopic surgery for gastric cancer (GC). However, randomized controlled trials (RCTs) reporting the differences in survival between these two approaches are currently lacking. From September 2017 to January 2020, 300 patients with cT1-4a and N0/+ were enrolled and randomized to either the robotic (RDG) or laparoscopic distal gastrectomy (LDG) group (NCT03313700). The primary endpoint was 3-year disease-free survival (DFS); secondary endpoints reported here are the 3-year overall survival (OS) and recurrence patterns. The remaining secondary outcomes include intraoperative outcomes, postoperative recovery, quality of lymphadenectomy, and cost differences, which have previously been reported. There were 283 patients in the modified intention-to-treat analysis (RDG group: n = 141; LDG group: n = 142). The trial has met pre-specified endpoints. The 3-year DFS rates were 85.8% and 73.2% in the RDG and LDG groups, respectively (p = 0.011). Multivariable Cox regression model including age, tumor size, sex, ECOG PS, lymphovascular invasion, histology, pT stage, and pN stage showed that RDG was associated with better 3-year DFS (HR: 0.541; 95% CI: 0.314-0.932). The RDG also improved the 3-year cumulative recurrence rate (RDG vs. LDG: 12.1% vs. 21.1%; HR: 0.546, 95% CI: 0.302-0.990). Compared to LDG, RDG demonstrated non-inferiority in 3-year DFS rate.

Fig. 1. Trial profile.

Randomized controlled trial flowchart.

Fig. 2. Kaplan-Meier curves of disease-free survival for robotic and laparoscopic distal gastrectomies within 3 years after surgery.

The shadows on either side of the survival curves indicate 95% confidence intervals. p-values for all survival analyses have been calculated using the log-rank test. Adjusted p value was calculated using Benjamini–Hochberg method. Source data are provided as a Source Data file.

Fig. 3. Kaplan-Meier curves of disease-free survival for robotic and laparoscopic distal gastrectomies within 3 years after surgery by different pathologic T stage and N stage.

A patients with pT1 stage; B patients with pT2-4 stage; C patients with pN0 stage; D patients with pN+ stage. p-values for all survival analyses have been calculated using the log-rank test. The shadows on either side of the survival curves indicate 95% confidence intervals. Adjusted p value was calculated using Benjamini–Hochberg method. Source data are provided as a Source Data file.

Fig. 4. Subgroup analysis of disease-free survival including age, sex, ECOG PS, lymphovascular invasion, histology, tumor size, postoperative complication, and adjuvant chemotherapy (RDG [n = 141] vs. LDG [n  = 142]).

Forest plots show the hazard ratio (HR) as centers, and the upper and lower hinges represent the corresponding 95% confidence intervals (CIs). A Cox proportional hazard model without stratification factors was used to calculate HRs for group comparisons. P values were two-sided at the 5% significance level and adjusted by the Benjamini–Hochberg method. Source data are provided as a Source Data file.