Risk of gastric cancer among long-term proton pump inhibitor users: a population-based cohort study

Abstract

Purpose: To elucidate whether long-term proton pump inhibitor (PPI) users have an increased gastric cancer (GC) risk. Methods: We searched the 2009–2019 Korean National Health Insurance Services Database for patients aged > 40 years who claimed for Helicobacter pylori eradication (HPE) during 2009–2014. The GC incidence following a PPI exposure of > 180 cumulative defined daily dose (cDDD) and that following an exposure of < 180 cDDD were compared. The outcome was GC development at least 1 year following HPE. A propensity score (PS)–matched dataset was used for analysis within the same quartiles of the follow-up duration. Additionally, dose–response associations were assessed, and the mortality rates were compared between long-term PPI users and non-users. Results: After PS matching, 144,091 pairs of PPI users and non-users were analyzed. During a median follow-up of 8.3 (interquartile range, 6.8–9.6) years, 1053 and 948 GC cases in PPI users and non-users, respectively, were identified, with the GC incidence (95% confidence interval (CI)) being 0.90 (0.85–0.96) and 0.81 (0.76–0.86) per 1000 person-years, respectively. The adjusted hazard ratio (aHR) for GC with PPI use was 1.15 (95% CI, 1.06–1.25). Among PPI users, patients in the highest tertile for annual PPI dose showed higher GC development than those in the lowest tertile (aHR (95% CI): 3.87 (3.25–4.60)). GC–related mortality did not differ significantly between PPI users and non-users. Conclusion: In this nationwide analysis in Korea, where the GC prevalence is high, long-term PPI use after HPE showed a significant increase in GC, with a positive dose–response relationship.