Outcomes of endoscopic resection for superficial duodenal tumors: 10 years' experience in 18 Japanese high volume centers

Background Data on endoscopic resection (ER) for superficial duodenal epithelial tumors (SDETs) are insufficient owing to their rarity. There are two main ER techniques for SDETs: endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). In addition, modified EMR techniques, such as underwater EMR (UEMR) and cold polypectomy, are becoming popular. We conducted a large-scale retrospective multicenter study to clarify the detailed outcomes of duodenal ER. Methods Patients with SDETs who underwent ER at 18 institutions from January 2008 to December 2018 were included. The rates of en bloc resection and delayed adverse events (AEs; defined as delayed bleeding or perforation) were analyzed. Local recurrence was analyzed using the Kaplan–Meier method. Results In total, 3107 patients (including 1017 undergoing ESD) were included. En bloc resection rates were 79.1 %, 78.6 %, 86.8 %, and 94.8 %, and delayed AE rates were 0.5 %, 2.2 %, 2.8 %, and 6.8 % for cold polypectomy, UEMR, EMR and ESD, respectively. The delayed AE rate was significantly higher in the ESD group than in non-ESD groups for lesions 20 mm (6.1 % vs. 7.1 %; P = 0.64). The local recurrence rate was significantly lower in the ESD group than in the non-ESD groups (P 30 mm, the cumulative local recurrence rate at 2 years was 22.6 % in the non-ESD groups compared with only 1.6 % in the ESD group (P Conclusions ER outcomes for SDETs were generally acceptable. ESD by highly experienced endoscopists might be an option for very large SDETs.