Risk assessment of metachronous gastric cancer after endoscopic submucosal dissection based on endoscopic intestinal metaplasia.

Background and Aim: The incidence of metachronous gastric cancer (MGC) after endoscopic treatment for early gastric cancer (EGC) is high, but a method of risk assessment for MGC based on endoscopic findings has not been established. In this study, we focused on endoscopic intestinal metaplasia (IM) and investigated the risk for MGC after endoscopic submucosal dissection (ESD) for EGC. Methods: This retrospective observational study involved patients who underwent curative ESD for EGC from April 2015 to January 2021. We assessed endoscopic IM using the pretreatment endoscopic examination images. The severity of endoscopic IM was classified into four levels: 0 (none), 1 (mild), 2 (moderate), and 3 (severe). Four different gastric areas were evaluated. We divided the patients into a low-score group and a high-score group, and compared the cumulative incidence of MGC. Results: In total, 156 patients who met the inclusion criteria were followed up for at least 12 months after ESD, and MGC developed in 14 patients during a mean period oof 41.5 months. The endoscopic IM scores in the lesser curvature of the antrum, lesser curvature of the corpus, and greater curvature of the corpus were higher in patients with MGC than in those without MGC. In the corpus, the 5-year cumulative incidence of MGC was significantly higher in the high-score group than in the low-score group (29.8% Conclusion: The severity of endoscopic corpus IM was associated with MGC. Thus, patients with severe corpus IM at the time of ESD require careful examination and intensive follow-up.