Looks like there is yet another reason to rethink the long-term use of proton pump inhibitors. And this one is a doozy.According to a new study, recently published in the BMJ journal, Gut, the long-term use of PPIs is linked to a more than doubling of the risk of developing stomach cancer.And before you jump to the reasonable conclusion that these patients might have had untreated Helicobacter Pylori, this 2.4 fold increase in gastric cancer risk occurred in patients who had had H.pylori but had been successfully treated more than 12 months previously.What’s more, the risk increased proportionally with the duration of PPI use and the dose, which the Hong Kong authors said suggested a cause-effect relationship. No such increased risk was found among those patients who took H2 receptor antagonists.While the study was observational, the large sample size (more than 63,000 patients with a history of effective H.pylori treatment) and the relatively long duration of follow-up (median 7.6 years) lent validity to the findings.The link between H.pylori and gastric cancer, has been known for decades. It has been shown that eradicating H.pylori reduces the risk of developing gastric cancer by 33-47%. However, the study authors said, it is also known that a considerable proportion of these individuals go on to develop gastric cancer even after they have successfully eradicated the bacteria.“To our knowledge, this is the first study to demonstrate that long-term PPI use, even after H. pylori eradication therapy, is still associated with an increased risk of gastric cancer,” they said.By way of explanation, the researchers note that gastric atrophy is considered a precursor to gastric cancer. And while gastric atrophy is a known sequela of chronic H. pylori infection, it could also be worsened and maintained by the profound acid suppression associated with PPI use and this could be why the risk persisted even after the infection had been treated.Bottom line? According to the study authors, doctors need to ‘exercise caution when prescribing long-term PPIs to these patients even after successful eradication of H. pylori.’Ref:Gut 2017; 0:1-8. Doi:10.1136/gutjnl-2017-314605
Expert/s: Dr Linda Calabresi