Antibiotics that target ulcer-causing bacteria also prevent stomach cancer

Antibiotics that eradicate Helicobacter pylori bacteria in the stomach have at least a small benefit in preventing gastric cancer. But the jury is still out whether this treatment actually decreases cancer deaths, according to a comprehensive review in the Cochrane Library.

“The findings of this systematic review and meta-analysis add to the increasing evidence that eradicating H. pylori in the general population has the potential to prevent gastric cancer. International guidelines for the management of H. pylori infection may change as a result,” said study co-author Paul Moayyedi, PhD, of McMaster University in Hamilton, Ontario, Canada.

About two-thirds of the world’s population are infected with H. pylori, and its role as a major risk factor for gastric ulcers is well known. Those who are infected are also more likely to develop gastric cancer—the third most common cause of cancer death worldwide. However, H. pylori infection is easily treatable with a one-week course of antibiotics.

To determine whether eliminating H. pylori might reduce the incidence of gastric cancer, researchers at centers in Canada, France, and the United Kingdom analyzed all published randomized controlled trials that compared at least one week of H. pylori therapy with placebo or no treatment in otherwise healthy and asymptomatic but infected adults. The review included only trials that followed participants for at least 2 years and that had at least 2 participants who developed gastric cancer.

Six trials with a total of nearly 6,500 participants met the researchers’ criteria. One study was conducted in Colombia and the others were conducted in Asian countries (China and Japan) where stomach cancer is more common. The studies mainly used a treatment combination of antibiotics and proton pump inhibitors that suppress gastric acid production.

An analysis of the studies’ results revealed that a 1- to 2-week course of antibiotic/gastric acid suppressor therapy resulted in fewer gastric cancers in treated patients (1.6%) compared with gastric cancers that occurred in subjects given placebo or no treatment (2.4%).

The researchers acknowledged that the number of deaths from gastric cancer in the trials was low, which offered insufficient evidence to determine whether eradication improved survival.

“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,” Dr. Moayyedi said.