Endoscopic resection for colorectal laterally spreading tumors in East Asian countries: a systematic review

Background: To assess the efficacy and safety of different endoscopic resection methods for colorectal laterally spreading tumors (LSTs) in East Asian countries. Methods: A literature search was performed in PubMed, Embase, Cochrane Library and Web of Science databases. Colorectal LSTs of the included studies were resected with endoscopic mucosal resection (EMR) and/or endoscopic submucosal dissection (ESD). The main outcomes involved rates of en bloc resection, R0 resection, adverse events and recurrence. Results: A total of 20 studies were finally included in the present study. The total number of lesions were 3,903 (EMR: 1,230, ESD: 2,673). EMR-en bloc resection was obtained in 395/591 (66.8%), with ESD-en bloc resection reported in 2,020/2,265 (89.2%) [odds ratio (OR) 0.244, P<0.0001, 95% confidence interval (CI): 0.197-0.304]. EMR-R0 resection was achieved in 409/547 (74.8%), which was lower than that of ESD (1,895/2,241, 84.6%) (OR 0.541, P<0.0001, 95% CI: 0.432-0.677). Bleedings occurred more frequently in EMR than in ESD group (10.4% vs. 3.1%, OR 3.559, P<0.0001, 95% CI: 2.618-4.836). Rates of perforations in EMR and ESD were 0.4% and 4.1% (OR 0.099, P<0.0001, 95% CI: 0.036-0.27). Recurrence of EMR was higher than ESD group (6.3% vs. 1.0%, OR 6.732, P<0.0001, 95% CI: 3.751-12.082). Discussion: Endoscopic resections of colorectal LSTs are safe and effective. ESD leads to higher rates of en bloc and R0 resection, as well as lower rates of bleeding and recurrence, but it has a high risk of perforation, compared with EMR.