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

SIMPLE SUMMARY: Community-driven projects have characterized health impacts of Helicobacter pylori (Hp) infection in Indigenous communities in the Northwest Territories (NT) and Yukon (YT), Canada. These projects address concerns expressed by community leaders about the frequent diagnosis of Hp infection and its relation to gastric cancer deaths, perceived to occur with alarming frequency in this region. Previous project results showed a high prevalence of stomach pathologies associated with increased cancer risk among Hp-positive participants at baseline. This follow-up study investigated changes in precancerous stomach pathologies after treatment to eliminate Hp infection among 69 project participants with follow-up data. Most participants who had successful treatment to eliminate Hp at baseline remained infection-free at follow-up and the prevalence of precancerous stomach pathologies was lower at follow-up than baseline. The more frequent improvements in precancerous stomach pathologies observed in participants who were Hp-negative at follow-up relative to those who were Hp-positive at follow-up suggests that treatment to eliminate Hp infection has the potential to reduce stomach cancer risk in participating communities. ABSTRACT: Community-driven projects have characterized Helicobacter pylori (Hp) infection in Indigenous communities in the Northwest Territories (NT) and Yukon (YT), Canada. These projects address concerns about the frequent diagnosis of Hp 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 Hp infection, gastroscopy with gastric biopsies, and treatment to eliminate Hp infection. Previous project results showed a high prevalence of stomach pathologies associated with increased cancer risk among Hp-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 Hp 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 Hp infection and precancerous gastric pathology was substantially lower at follow-up; most participants who were Hp-positive at baseline and Hp-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 Hp treatment has the potential to reduce the risk of gastric cancer in Arctic Indigenous communities.