Proton pump inhibitors and all-cause mortality risk among cancer patients

Proton pump inhibitors (PPIs) are widely used, including among cancer patients, to manage gastroesophageal reflux and other gastric acid-related disorders. Recent evidence suggests associations between long-term PPI use and higher risks for various adverse health outcomes, including greater mortality. To investigate the association between PPI use and all-cause mortality among cancer patients by a comprehensive analysis after adjustment for various confounders and a robust methodological approach to minimize bias. This retrospective cohort study used data from the TriNetX research network, with electronic health records from multiple healthcare organizations. The study employed a new-user, active comparator design, which compared newly treated PPI users with non-users and newly treated histamine2 receptor antagonists (H2RA) users among adult cancer patients. Newly prescribed PPIs (esomeprazole, lansoprazole, omeprazole, pantoprazole, or rabeprazole) users were compared to non-users or newly prescribed H2RAs (cimetidine, famotidine, nizatidine, or ranitidine) users. The primary outcome was all-cause mortality. Each patient in the main group was matched to a patient in the control group using 1:1 propensity score matching to reduce confounding effects. Multivariable Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence interval (CI). During the follow-up period (median 5.4 ± 1.8 years for PPI users and 6.5 ± 1.0 years for non-users), PPI users demonstrated a higher all-cause mortality rate than non-users after 1 year, 2 years, and at the end of follow up (HRs: 2.34-2.72). Compared with H2RA users, PPI users demonstrated a higher rate of all-cause mortality HR: 1.51 (95%CI: 1.41-1.69). Similar results were observed across sensitivity analyses by excluding deaths from the first 9 months and 1-year post-exposure, confirming the robustness of these findings. In a sensitivity analysis, we analyzed all-cause mortality outcomes between former PPI users and individuals who have never used PPIs, providing insights into the long-term effects of past PPI use. In addition, at 1-year follow-up, the analysis revealed a significant difference in mortality rates between former PPI users and non-users (HR: 1.84; 95%CI: 1.82-1.96). PPI use among cancer patients was associated with a higher risk of all-cause mortality compared to non-users or H2RA users. These findings emphasize the need for cautious use of PPIs in cancer patients and suggest that alternative treatments should be considered when clinically feasible. However, further studies are needed to corroborate our findings, given the significant adverse outcomes in cancer patients.