Cold snare endoscopic mucosal resection versus standard hot technique for large flat non-pedunculated colonic lesions: Results of the CS-EMR 2019 randomized controlled trial

Backgrounds and Aims: Cold snare EMR (CS-EMR) in large flat non-pedunculated colonic lesions (LFNPCLs) is an alternative to the standard EMR procedure with a better safety profile, but scientific evidence on its efficacy is unavailable. Primary objective: To compare the recurrence rate between the two techniques at six months. Secondary objectives: comparison of the safety profile and several procedure-related outcomes. Patients and methods: This was a noninferiority, multicentric, open-label, randomized controlled trial of consecutive large (>20 mm) LFNPCLs without suspicious features of submucosal invasion. Results: A total of 229 patients were randomized to receive CS-EMR (n=115) or EMR (n=114), with adenomas (76.4%) and a median size of 25 mm. The trial was stopped early by clinical consensus according to a safety monitoring board. At first surveillance colonoscopy (n=220) the recurrence rate (RR) was significantly greater in the CS-EMR group than in the EMR group: 33.0% vs. 16.2% (p=0.004) and 34.7% vs. 14.8% (p=0.001) in the ITT and PP analyses, respectively. According to the subgroup analysis, the RR was significantly greater for LFNPCLs >30 mm (18.2% EMR vs. 43.1% CS-EMR). There was no difference in the rate of adverse events. The use of clips was more common in the EMR group (2.21 vs. 1.30). Conclusions: Compared with the conventional hot technique, the RR of LFNPCL after CS-EMR was significantly greater. A similar safety profile was found between groups.