Aberrant DNA Methylation Maker for Predicting Metachronous Recurrence After Endoscopic Resection of Gastric Neoplasms

Purpose This study aimed to investigate whether MOS methylation can be useful for the prediction of metachronous recurrence after endoscopic resection of gastric neoplasms. Materials and Methods From 2012 to 2017, 294 patients were prospectively enrolled after endoscopic resection of gastric dysplasia (n=171) or early gastric cancer (n=123). When Helicobacter pylori was positive, eradication therapy was performed. Among them, 124 patients completed the study protocol (follow-up duration > 3 years or development of metachronous recurrence during the follow-up). Methylation levels of MOS were measured at baseline using quantitative MethyLight assay from the antrum. Results Median follow-up duration was 49.9 months. MOS methylation levels at baseline were not different by age, sex, and current H. pylori infection, but they showed a weak correlation with operative link on gastritis assessment (OLGA) or operative link on gastric intestinal metaplasia assessment (OLGIM) stages (Spearman's ?=0.240 and 0.174, respectively; p < 0.05). During the follow-up, a total of 20 metachronous gastric neoplasms (13 adenomas and 7 adenocarcinomas) were developed. Either OLGA or OLGIM stage was not useful in predicting the risk for metachronous recurrence. In contrast, MOS methylation high group (> 34.82%) had a significantly increased risk for metachronous recurrence compared to MOS methylation low group (adjusted hazard ratio, 4.76; 95% confidence interval, 1.54 to 14.79; p=0.007). Conclusion MOS methylation can be a promising marker for predicting metachronous recurrence after endoscopic resection of gastric neoplasms. To confirm the usefulness of MOS methylation, validation studies are warranted in the future (ClinicalTrials No. NCT04830618).