Proton pump inhibitors (PPIs) are amongst the most prescribed medications in the whole world due to their effectiveness and safety profile. However, doubts have arisen about its safety in long term use and have been associated with an increased risk of developing gastric cancer. We aim to study if there is an association between chronic PPI use and the risk of gastric cancer. If this is true, we would like to know the duration of use at which the risk of cancer is high. We performed a literature review of relevant full articles present in the PubMed database that were published in the last five years. Articles that were in the English language and discussed the risk of gastric cancer with chronic PPI use in adult age groups (18 years and above) were evaluated. Only observational or interventional studies with more than 20,000 participants were considered. Two nationwide based studies were included in this review, the Cheung study, and the Brusselaers study. The Cheung study included a total of 63,397 individuals, where 153 cases developed gastric cancer. PPI users had a hazard ratio of 2.44 (95% confidence interval [CI] 1.42-4.20), and the risk of cancer increased with the duration of PPI use. The Brusselaers study included a total of 797,067 individuals, where 2,219 cases developed gastric cancer. The standardized incidence ratio of gastric cancer among PPI users was 3.38 (95% CI 3.23-3.53), and the risk of cancer increased with the duration of PPI use. Therefore, chronic PPI use is associated with an increase in the risk of gastric cancer. It might also be an independent risk factor for gastric cancer.
Keywords: gastric cancer; helicobacter pylori; long term use; omeprazole; pantoprazole; proton pump inhibitors; stomach neoplasms.