Incidence of metachronous gastric neoplasia after endoscopic submucosal dissection for gastric dysplasia.

Abstract

20 Background: Endoscopic submucosal dissection (ESD) has been usually performed to treat gastric high-grade dysplasia (HGD) and selected lesions of low-grade dysplasia (LGD). However, HGD was classified into the same category of non-invasive carcinoma which were different from LGD in the Vienna classification of gastrointestinal epithelial neoplasia. We investigated whether the incidence of metachonous gastric neoplasia after ESD for gastric dysplasia is different between patients with LGD and HGD. Methods: Between March 2011 and December 2016, 508 patients underwent ESD for 545 gastric dysplasias or cancers at the Chung-Ang University Hospital. Of them, 198 patients with LGD (LGD group) and 46 with HGD (HGD group) who had been followed up for at least one year were included. The primary outcome was the incidence of gastric neoplasia occurred at 1-year follow-up or later after ESD. The secondary outcome was the composite incidence of metachronous HGD and gastric cancers. Results: During a median follow-up of 2.5 years, overall cumulative incidence of metachronous gastric neoplasm was 33.2 cases/1000 person-years. The metachronous neoplasms developed in 17 patients (8.6%; 11 LGD, 2 HGD and 4 gastric cancers) in the LGD group and in 6 patients (13.0%; 3 LGD, 1 HGD and 3 gastric cancers) in the HGD group. The incidence of metachronous gastric neoplasia in LGD group was not significantly different from that in HGD group (hazard ratio [HR] in the LGD group, 0.56; 95% confidence interval [CI], 0.22-1.43; P = 0.229). The composite incidences of metachronous HGD and gastric cancers were not also different between the two groups (HR for the composite incidences in the LGD group, 0.42; 95% CI, 0.10-1.68; P = 0.218). Conclusions: After ESD for gastric LGD, the incidence of metachronous gastric neoplasia was not different from that after ESD for HGD. Thus, similar surveillance strategies are needed for patients who underwent ESD for LGD and HGD.