Endoscopic submucosal dissection as a treatment for gastric noninvasive neoplasia: a multicenter study by Osaka University ESD Study Group

Treatment with endoscopic submucosal dissection (ESD) for gastric noninvasive neoplasia (NIN) diagnosed by endoscopic forceps biopsy specimen, whether as a follow-up or total incisional biopsy, is controversial. To validate the use of ESD for total incisional biopsy in NIN, we examined the underdiagnosis rate of NIN and the rates of complication associated with ESD. This is a cross-sectional multicenter retrospective study from 10 hospitals. Subjects diagnosed with NIN (equivalent to category 3 or 4.1 of the Vienna classification) by endoscopic forceps biopsy and treated with ESD were included. From March 2003 to December 2009, a total of 468 subjects were included and analyzed. The underdiagnosis rate was defined as the proportion of lesions diagnosed with adenocarcinoma after ESD. We assessed the complete en-bloc resection rate and the complication rate of ESD. Among the 468 subjects with NIN, 205 were diagnosed with adenocarcinoma after ESD, with an underdiagnosis rate of 44% (95% confidence interval: 39-49%). Two submucosal cancer lesions had invaded beyond 500 mu m and one had lymphatic involvement. The complete en-bloc resection rate was 97%. The incidences of post-ESD bleeding, perforation, and serious complications were 5.5, 4.7, and 0.43%, respectively. There were no procedure-related deaths. In this large-scale, multicenter cross-sectional study, over 40% of the noninvasive gastric neoplasia specimens were determined to have adenocarcinoma, and the ESD-related complication rate was relatively low. Therefore, ESD was useful and may be a therapeutic option for gastric NIN.