Long-term use of proton pump inhibitors (PPIs), a common treatment for acid reflux and ulcers, has been the subject of ongoing safety concerns. A new, decades-long study involving over 17,000 patients offers significant reassurance, finding no substantial link between PPI use and an increased risk of gastric adenocarcinoma, the moast prevalent form of stomach cancer. The research, spanning 26 years and conducted across five Nordic countries, provides a robust analysis of this frequently prescribed medication class and may impact clinical practice for the over 15% of Americans who report regularly taking a PPI [[1]].
A large, decades-long study is offering reassurance about the long-term safety of proton pump inhibitors (PPIs), a commonly prescribed class of medications used to reduce stomach acid. Concerns have lingered for years about a potential link between PPI use and an increased risk of gastric cancer, but new research suggests those fears may be largely unfounded.
The study, which analyzed health records from over 17,000 patients with gastric cancer and compared them to more than 172,000 healthy individuals across five Nordic countries, found no significant association between PPI use and the development of gastric adenocarcinoma, the most common type of stomach cancer. The research spanned a 26-year period, from 1994 to 2020.
Researchers utilized a case-control study design, a robust methodology for evaluating exposures – in this case, PPIs – that require a long observation period. This approach compares individuals diagnosed with a condition to those without, while statistically adjusting for other factors like age, sex, and risk factors. “This study has a case-control design, in which patients diagnosed with a pathology (in this case, gastric adenocarcinoma) are compared with others without that problem, while being similar or statistically adjusted for other factors such as age, sex, risk factors, etc., which provides an adequate and quality methodology to evaluate exposures (the proton pump inhibitors in this example) that require a very long observation period.”
Historically, some studies suggested that PPIs might increase the risk of gastric cancer by elevating gastrin levels. Recent meta-analyses even estimated the risk could double. However, the new findings clarify the situation by demonstrating that when key factors like Helicobacter pylori infection, smoking, obesity, and diabetes are accounted for, the apparent association disappears. “These new findings clarify the situation by demonstrating that, once determinants such as infection by the bacterium Helicobacter pylori, smoking, obesity and diabetes are adjusted for, the supposed association disappears,” researchers said.
The study’s large sample size and access to detailed clinical information helped mitigate weaknesses found in previous research on the topic. The inclusion of data from multiple countries also strengthens the study’s external validity, meaning the results are more likely to be applicable to broader populations. “In addition to this, data from health records from five Nordic countries have been included for a period of 26 years (1994-2020), which increases its external validity. On the other hand, by including more than 17,000 patients with cancer and comparing them with more than 172,000 healthy people, together with access to detailed clinical information, the researchers managed to mitigate many of the weaknesses that affected previous investigations on this same topic.”
For healthcare professionals and patients alike, the findings offer reassurance about the long-term safety of PPIs, one of the most frequently prescribed medications. The results could help streamline clinical decision-making and bolster confidence in these treatments, which are often necessary for long-term management of conditions like acid reflux and ulcers. “Both for all healthcare personnel and patients, this finding is of great value and interest, as it provides peace of mind and reaffirms the safety of proton pump inhibitors in the long term, one of the most prescribed drugs in Spain. By eliminating some of the doubts about this increased risk, the results facilitate clinical decision-making and increase (even more) our confidence with these treatments necessary, on many occasions in the long term, with a more solid evidence base.”
While the data is robust, researchers caution that the study is observational and cannot definitively prove a cause-and-effect relationship. Factors like diet, family history of stomach cancer, and geographic predisposition, which weren’t fully measured, could also play a role. Additionally, the study focused specifically on adenocarcinoma, and doesn’t encompass all types of gastric cancer. “Although the data is solid and has significantly improved the limitations of previous studies, we must remember that this is an observational study, which means that it cannot establish a definitive cause-and-effect relationship. In addition, despite the researchers’ efforts, there are factors that could not be measured, such as the patients’ diet, their family history of stomach cancer, or the variable predisposition to this type of cancer in certain geographical areas, and which, together with others, could influence the results.”
Despite these limitations, the study provides one of the most reliable perspectives on the relationship between PPIs and gastric cancer to date, offering valuable insights for both clinical practice and public health. The findings underscore the importance of considering multiple factors when assessing cancer risk and highlight the need for continued research in this area.
