Multicenter phase 3 trial of robot-assisted versus conventional minimally invasive esophagectomy for esophageal squamous cell carcinoma

Robot-assisted minimally invasive esophagectomy is used increasingly worldwide. The phase 3 RAMIE trial, at sicx centers in China has compared long-term survival as the primary endpoint between robot-assisted esophagectomy and conventional thoracoscopic esophagectomy in patients aged 18 to 75 years with resectable ESCC, ECOG performance status 0-2, and with tumor and nodal classifications of cT1-4a, N0-2, M0 or M1 (supraclavicular lymph node metastasis. Patients were randomized to robot-assisted esophagectomy (n=183) or thoracoscopic esophagectomy (n=179). The primary endpoint was overall survival. Median follow-up for the planned analysis was 71.5 months (IQR 63.9-81.8). At five years, overall survival was 69.4% (95% CI 62.1-75.6) with robot-assisted esophagectomy and 56.2% (48.5-63.2) with thoracoscopic esophagectomy (HR 0.71; 95% CI0.51-0.97), confirming noninferiority (p=0.0001; exploratory analysis of p=0.032 for superiority). Intraoperative conversions to open surgery were similar betweenstudy groups, as were postoperative grade 3 or higher complications. One treatment-related death occurred in each group. The authors conclude that in patients with resectable ESCC, robot-assisted esophagectomy was noninferior, and seemed superior, to thoracoscopic esophagectomy in terms of 5-year overall survival.