Inclusion Criteria:  Adults >= 18 years of age Written informed consent obtained Diagnosed with current or past H. pylori infection, Histologically proven atrophic gastritis (body and/or antrum of stomach), intestinal metaplasia (complete and incomplete), dysplasia (any grade) and/or gastric cancer (post- treatment)  Exclusion Criteria:  Co-morbid illness that prohibit endoscopic surveillance Declines for study questionnaire, biobanking of specimens and/or regular review per study protocol