It’s been a hard year for heartburn drugs. First, they were linked with kidney damage. Then, further studies suggested they’re associated with an increased risk of death. Now, long-term use of these drugs – known as proton pump inhibitors (PPI) – has been associated with double the risk of stomach cancer.
The new findings were published in the journal, Gut and may have worrying implications for the millions of people in the US who take the acid reducers.
Patients exhibiting symptoms of acid reflux are often tested for a bacterial strain known as Helicobacter pylori. This pathogen has been implicated in the development of stomach cancer, so patients who test positive for the bacteria are prescribed a course of antibiotics in order to eliminate it.
While this can substantially lower a person’s risk of developing stomach cancer, the recent study found that long-term use of PPIs still increased this risk in individuals who were negative for H. pylori. As stomach cancer is currently the third leading cause of cancer death globally, identifying potential risk factors is of the utmost importance.
In their study, the researchers compared the use of PPIs with histamine H2 receptor antagonists (H2 blockers), which are also commonly used to inhibit excess stomach acid production. Over 63,000 patients were included in the 9-year study, with PPIs being taken alongside two antibiotics to eliminate H. pylori, over the course of one week.
In all, 3,271 study participants were prescribed PPIs for an average of three years, while over 21,000 participants took H2 blockers. One hundred and fifty individuals taking PPIs along with two antibiotics developed stomach cancer over the follow-up period.
The researchers concluded that patients taking PPIs were over two times more likely to develop stomach cancer, compared to those taking the H2 blockers. Importantly, none of the patients diagnosed with stomach cancer tested positive for H. pylori at the time.
The risk of developing stomach cancer was also found to be linked to the duration and dose of the PPIs. Patients who took the medication daily were more than 4 times as likely to develop stomach cancer, and patients taking PPIs for more than one year faced a five-fold greater risk.
While the patient population taking PPIs in this study was relatively small compared to the sample size as a whole, the results are still concerning. While the findings do not prove causation, the researchers still urge doctors to be cautious when prescribing PPIs to patients with acid reflux.