The study investigated the relationship between long-term use of proton pump inhibitors (PPIs) and gastric cancer risk in five Nordic countries using a population-based case-control study.[1] The research included 17,027 gastric adenocarcinoma cases and 172,297 controls, with long-term PPI use (more than 1 year) occurring in 10.2% of cases and 9.5% of controls.[1] The main finding was that long-term use of proton pump inhibitors was not associated with an increased risk of gastric adenocarcinoma, with an adjusted odds ratio of 1.01 (95% confidence interval 0.96 to 1.07).[1] A similar result was also found with the use of histamine-2-receptor antagonists, where the adjusted odds ratio was 1.03.[1] The authors identified several methodological flaws in previous studies that led to false-positive associations, including the inclusion of PPI use shortly before diagnosis and insufficient adjustment for Helicobacter pylori-related variables.[1] The conclusion of the study suggests that long-term use of proton pump inhibitors may not be associated with an increased risk of gastric adenocarcinoma.[1]