Gastric Cancer Risk in Patients with Long-Term Use of Proton Pump Inhibitors: A Systematic Review and Meta-Analysis of Observational and Interventional Studies.

ABSTRACT

BACKGROUND: A growing number of studies that differ in design, quality, and results report an association between the use of proton pump inhibitors (PPIs) and the risk of gastric cancer (GC). We conducted a systematic review and meta-analysis, when possible, of observational and interventional studies examining PPI use and risk of GC. METHODS: We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We identified studies fully published in English through January 2023 using MeSH and non-MeSH keywords. We used random effects models to calculate pooled risk estimates with 95% confidence interval (CI) between PPI use and overall GC, cardia GC, and non-cardia GC. We estimated heterogeneity (I2) among studies. We examined the effect of study design and quality, GC site, H. pylori infection, and PPI duration. We assessed quality using the Newcastle-Ottawa Quality Assessment Scale and Risk Of Bias In Non-randomized Studies of Interventions. RESULTS: We identified 15 observational studies, of which 13 were included in the meta-analysis (six cohort and seven case-control). There was a modest 1.67-fold increase in overall GC risk (95% CI 1.39, 2.00) and no increase in cardia GC risk [odds ratio (OR) 1.12; 95% CI 0.80, 1.56] with PPI use. However, there was high heterogeneity (I2 = 61.3%, p = 0.004) among studies. All but one study had at least moderate risk of bias. In the six studies accounting for H. pylori, GC risk associated with PPI use increased slightly (OR 1.78; 95% CI 1.25, 2.52). Duration response was not reported consistently to allow pooled estimates. We identified only one interventional randomized controlled study that included GC as an outcome of interest, and it did not show increased GC risk. CONCLUSIONS: The overall available evidence is not supportive of a meaningful change in GC risk, either cardia or non-cardia, with PPI use.