Robotic versus laparoscopic surgery for middle and low rectal cancer (REAL): Primary outcome of a multicenter randomized controlled trial.

3617 Background: Robotic surgery for rectal cancer is gaining popularity, but persuasive evidence on long-term oncological outcomes is lacking. This multicenter randomized controlled trial compared robotic and conventional laparoscopic surgery regarding surgical quality and long-term oncological outcomes among patients with middle and low rectal cancer. Previously the short-term outcomes of this trial had been reported that robotic surgery had significantly lower circumferential resection margin positivity rate, lower postoperative complication rate, and better postoperative recovery. Now the long-term oncological outcomes were reported. Methods: This superiority trial was undertaken at 11 hospitals in 8 Chinese provinces. Patients with middle (> 5–10 cm from anal verge) or low (0–5 cm from anal verge) rectal adenocarcinoma, cT1–T3 N0–1 or ycT1–T3 Nx after preoperative radio-/chemoradiotherapy, and no evidence of distant metastasis were enrolled and randomly assigned in a 1:1 ratio to receive robotic or conventional laparoscopic surgery. The 3-year locoregional recurrence rate was the primary outcome and was compared using modified intention-to-treat (mITT) analysis. Secondary outcomes included disease-free survival and overall survival. All time-to-event outcomes were calculated using Kaplan-Meier method with log-rank test. This trial was registered with ClinicalTrials.gov (NCT02817126). Results: Between July 2016 and December 2020, 1240 patients were enrolled, and 1171 were included in the mITT analysis (586 in robotic and 585 in laparoscopic group). The pathological TNM stage of the mITT population was 73 (6.2%) patients with complete response, 346 (29.5%) with stage I, 368 (31.4%) with stage II, 384 (32.8%) with stage III. And the median follow-up time was 43.0 months (interquartile range = 36.7 to 60.0), with 34 (2.9%) patients lost to follow-up. The 3-year locoregional recurrence rate in robotic group (1.5%) was significantly lower than in laparoscopic group (4.0%, log-rank p=0.025, hazard ratio = 0.451, 95% confidence interval = 0.221 to 0.921). Robotic group also had significantly higher 3-year disease-free survival rate (87.3% vs. 83.6%, log-rank p=0.035). No significant difference was observed in 3-year overall survival rate (94.8% vs. 93.1%, log-rank p=0.155). Conclusions: Robotic surgery for middle and low rectal cancer significantly reduced locoregional recurrence and improved disease-free survival, compared with conventional laparoscopic surgery. Clinical trial information: NCT02817126 .