Feasibility of endoscopic resection and impact of endoscopic ultrasound-based surveillance on colorectal subepithelial tumors.

Background: Owing to the rising number of screening endoscopies and instrumental advances in endoscopic ultrasound (EUS), colorectal subepithelial tumors (SETs) are being increasingly detected. We aimed to determine the feasibility of endoscopic resection (ER) and the impact of EUS-based surveillance on colorectal SETs.

Methods: The medical records of 984 patients with incidentally detected colorectal SETs between 2010 and 2019 were retrospectively reviewed. Overall, 577 colorectal SETs underwent ER, and 71 colorectal SETs underwent serial colonoscopy for > 12 months.

Results: The mean tumor size (± standard deviation) of 577 colorectal SETs for which ER was performed was 7.0 ± 5.7 (median, 55; range, 1-50) mm; 475 tumors were located in the rectum and 102, in the colon. En bloc resection was achieved in 560/577 treated lesions (97.1%), and complete resection was achieved in 516/577 (89.4%). ER-related adverse events occurred in 15/577 (2.6%) patients. SETs originating from the muscularis propria showed a higher risk of ER-related adverse events and perforation than SETs arising from the mucosal or submucosal layer (odds ratio [OR] 19.786, 95% confidence interval [CI] 4.556-85.919; P = 0.002 and OR 141.250, 95% CI 11.596-1720.492; P = 0.046, respectively). Seventy-one patients were followed up after EUS without any treatment for > 12 months, during which three showed progression; eight, regression; and sixty, no changes.

Conclusions: ER for colorectal SETs showed excellent efficacy and safety. Additionally, colorectal SETs without high-risk features in surveillance with colonoscopy showed an excellent prognosis.