Treating common bacterial infection could help prevent stomach cancer
"Further research will be needed to determine whether the benefits of treating H. pylori infection outweigh any possible risks" - Casey Dunlop, Cancer Research UK
Canadian scientists analysed the findings of six trials conducted in Asia and South America. The researchers found that combining antibiotic treatment with drugs that suppress stomach acid production for just one to two weeks helped prevent the development of stomach cancer later on.
Casey Dunlop, health information officer at Cancer Research UK, said the findings confirmed previous research indicating a potential benefit in targeting the infection.
“This is an interesting analysis of several different studies, which confirms that finding and treating H. pylori infection in otherwise healthy people without symptoms can reduce their chances of subsequently developing stomach cancer,” she said.
“But the benefits appear small, with the analysis suggesting that you would need to treat 124 people infected with H. pylori to prevent one case of stomach cancer,” she added.
Although rates vary widely between countries, around two-thirds of the global population have an H. pylori infection, but in most cases it causes no discomfort or other symptoms.
But aside from its link to stomach cancer, H. pylori is the main cause of stomach ulcers, so is often eradicated with a combination of antibiotics together with drugs that suppress stomach acid production – called Proton Pump Inhibitors (PPIs).
In the new analysis, researchers led by Dr Paul Moayyedi at Canada’s McMaster University wanted to see if eradicating H. pylori with the treatment also reduced the risk of subsequent stomach cancer.
The team analysed the findings of six trials that included a total of around 6500 participants. The criteria for inclusion in the analysis was that each study must have followed participants for at least two years and include a minimum of two patients who later developed stomach cancer.
Across the studies, 1.6 per cent of those given the PPIs and antibiotic therapy for at least a week later developed gastric cancer – compared with 2.4 per cent of those given a placebo or no treatment.
But the study was unable to show whether the reduction in cases of stomach cancer would also result in a reduction in the number of deaths from the disease.
The analysis was also based on studies outside the UK, and Dunlop cautioned that the findings may not apply to people in this country.
“Stomach cancer is the third-leading cause of cancer death globally, so the findings of this analysis could prove important, especially in developing countries where stomach cancer is more common.
“But further research will be needed to determine whether the benefits of treating H. pylori infection outweigh any possible risks. And all of the studies included in this analysis took place outside the UK, so it’s not clear how relevant this is to people in this country,” she said.
And while Moayyedi acknowledged that the findings were encouraging, he also said that further studies would be necessary to better understand any potential harms from the treatment.
"More research is needed on the extent of this effect and on any potential harms of H. pylori treatment before it can be advocated as a means of preventing gastric cancer," he said.
The analysis is published by the Cochrane Library.
- H. pylori image by Yutaka Tsutsumi, via Wikimedia Commons