Abstract
Proton pump inhibitors (PPIs) are widely utilized in oncology to treat gastroesophageal reflux disease, peptic ulcer disease, and chemotherapy-induced mucosal injury. Emerging evidence has suggested that prolonged use of PPIs is associated with increased mortality in patients with cancer. The findings of Krishnan et al are proof of this but need to be considered cautiously due to potential confounding factors. This letter raised important methodological concerns, including confounding by indication, reverse causality, and polypharmacy that can influence the observed association. While PPIs are important in oncology, their advantages and disadvantages should be weighed judiciously by clinicians. Future prospective studies with robust analytical approaches will be required to ascertain more definite causality.