Efficacy and Safety of Gel Immersion Endoscopic Mucosal Resection for Gastric Neoplasms in Patients With Familial Adenomatous Polyposis: A Multicenter Retrospective Study

ABSTRACT Objectives Approximately 10%–30% patients with familial adenomatous polyposis (FAP) develop gastric neoplasms (GNs). Although recent reports have suggested the effectiveness of gel‐immersion endoscopic mucosal resection (GI‐EMR) for FAP‐associated GNs, given its simplicity and safety, treatment outcomes for such lesions have not been evaluated. We aimed to investigate the efficacy and safety of GI‐EMR compared with endoscopic submucosal dissection (ESD) for GNs in patients with FAP. Methods In this multicenter, retrospective study, treatment outcomes of ESD and GI‐EMR for GNs measuring ≤20 mm with protruding or flat elevated morphology between April 2011 and November 2024 were compared. Results This study included 15 ESD and 12 GI‐EMR cases. En bloc and R0 resection rates did not significantly differ between the ESD and GI‐EMR groups (100% vs. 100% and 100% vs. 83.3%, p = 0.19, respectively). The procedure time was significantly shorter for GI‐EMR than for ESD (2 vs. 47 min, p Conclusions GI‐EMR may be considered one of the therapeutic options for GNs in patients with FAP.