Changes in Gastric Pathology after Treatment in Community-Driven Research Aimed at Gastric Cancer Prevention.

Community-driven projects have characterized () infection in Indigenous communities in the Northwest Territories (NT) and Yukon (YT), Canada. These projects address concerns about the frequent diagnosis of infection among community members and its relation to gastric cancer deaths, perceived to occur with alarming frequency in this region. Projects included breath-test screening for infection, gastroscopy with gastric biopsies, and treatment to eliminate infection. Previous project results showed a high prevalence of stomach pathologies associated with increased cancer risk among -positive participants at baseline. This analysis describes changes in precancerous gastric pathologies in project participants who had gastroscopy before baseline treatment during 2008-2013 and again in 2017. Throughout the study period, the same pathologist graded density, active gastritis, chronic gastritis, atrophic gastritis, and intestinal metaplasia using the updated Sydney System. Of 310 participants from three communities with baseline pathology data, 69 had follow-up pathology data. Relative to baseline, the prevalence of infection and precancerous gastric pathology was substantially lower at follow-up; most participants who were -positive at baseline and -negative at follow-up had reduced severity of active, chronic, and/or atrophic gastritis at follow-up. Though follow-up numbers are small, these results yield evidence that successful treatment has the potential to reduce the risk of gastric cancer in Arctic Indigenous communities.