Impact of Helicobacter pylori Infection and Treatment on Colorectal Cancer in a Large, Nationwide Cohort
PURPOSE Helicobacter pylori is the most common cause of infection-associated cancer worldwide. We aimed to evaluate the impact of H. pylori infection and treatment on colorectal cancer (CRC) incidence and mortality. PATIENTS US Veterans who completed H. pylori testing between 1999 and 2018. METHODS We conducted a retrospective cohort analysis among adults within the Veterans Health Administration who completed testing for H. pylori. The primary exposures were (1) H. pylori test result (positive/negative) and (2) H. pylori treatment (untreated/treated) among H. pylori–positive individuals. The primary outcomes were CRC incidence and mortality. Follow-up started at the first H. pylori testing and continued until the earliest of incident or fatal CRC, non-CRC death, or December 31, 2019. RESULTS Among 812,736 individuals tested for H. pylori, 205,178 (25.2%) tested positive. Being H. pylori–positive versus H. pylori–negative was associated with higher CRC incidence and mortality. H. pylor