[Proton pump inhibitors and cancers: A hazardous association?]

Proton pump inhibitors, a major progress in gastro-enterology, are globally among the most widely prescribed drugs. But, due to their strong gastric acid inhibition, they can be responsible for side effects, particularly in cancer patients. They are involved in renal function impairment, bone fractures, digestive bacterial overgrowth, particularlyclostridium difficile infections, anemia and hypomagnesemia. Long term use can increase the risks of gastric, pancreatic and liver cancers. They decrease absorption of weak bases drugs, particularly tyrosine kinase inhibitors and capecitabine and are responsible for a poorer prognosis if taken concomitantly with erlotinib, gefitinib and pazopanib. Modification of cyclin dependent kinases is also possible as well as decrease of efficacy of immune check point inhibitors (microbiome modifications). Absoption and efficacy of capecitabine seem also poorer with negative prognosis effect on treatment of gastric and colon cancer. Their long term use, particularly in cancer patients, should probably be avoided.