BACKGROUND AND STUDY AIMS Natural history after endoscopic resection (ER) for gastric dysplasia is still unclear. The aim of this study was to evaluate the long-term clinical outcomes and risk factors after ER for gastric dysplasia between control and cases with synchronous or metachronous gastric neoplasm.

METHODS A total of 1090 patients who had undergone ER for gastric dysplasia and been followed up for at least one year from December 2002 to December 2013 were finally analyzed. Risk factors affecting the development of synchronous or metachronous neoplasm (SMN) and long-term clinical outcomes after ER for gastric dysplasia were evaluated.

RESULTS Synchronous and metachronous neoplasms had developed in 126 (11.6%) and 133 patients (12.2%) during the mean follow-up duration of 63.6 months, respectively. Five-year and 10-year risk of metachronous neoplasm were 9.8% and 27.2%, respectively. Median duration to the development of metachronous neoplasm was 103.1 months. While age (P < 0.001) and mucosal atrophy (P = 0.09) of index cases were associated with the development of synchronous neoplasm, age (P = 0.017), incomplete resection (P = 0.025), and intestinal metaplasia (P = 0.017) of background mucosa of index cases were significantly related to the development of metachronous neoplasm in multivariate analysis. Cumulative incidence of SMN was not significantly different among H. pylori negative, eradicated, and persistent group.

CONCLUSIONS Age, incomplete ER, and background intestinal metaplasia of index gastric dysplasia were significantly associated with metachronous recurrence. Endoscopic surveillance for metachronous recurrence after ER for gastric dysplasia is mandatory for longer than 10 years.