Effects of Proton Pump Inhibitors Intake During Chemoradiotherapy for Rectal Cancer: a Retrospective Cohort Study.

No significant association was observed between PPI co-medication and complete pathological response or survival in patients treated for locally advanced rectal cancer. However, the safety of PPIs could not be confirmed. Further ancillary studies of prospective clinical trials or studies using the Health Data Hub are necessary to explore the effects of PPIs on rectal cancer more accurately.