H. pylori eradication suppresses long-term gastric cancer risk

Helicobacter pylori eradication treatment leads to large reductions in the risk of gastric cancer and lower rates of associated deaths over 10 years of follow-up, according to a recent meta-analysis.

“This update of a previous meta-analysis, including only the four randomized controlled trials (RCTs) with ≥10 years of follow-up, demonstrates an even stronger effect of eradication therapy in preventing gastric cancer and gastric cancer-related mortality,” the researchers said.

Drawing from previous analyses and incorporating two recently published papers, this meta-analysis synthesized four RCTs enrolling a cumulative of 5,292 healthy, H. pylori-positive individuals. Follow-up durations ranged from 10 to 26.5 years. The primary outcome of interest was the occurrence of gastric cancer, while the impact of eradication on cancer-related mortality was set as a secondary endpoint.

Of the 2,660 patients who received eradication therapy, 69 cases of gastric cancers occurred during follow-up, corresponding to an incidence rate of 2.6 percent. In comparison, 127 (4.8 percent) such malignancies were reported in the 2,632 participants in placebo/no-treatment arms. [Gastroenterology 2022;doi:10.1053/j.gastro.2022.05.027]

Applying a random effects model on the pooled data revealed that eradication therapy significantly reduced the risk of gastric cancer by nearly half as compared with placebo (relative risk [RR], 0.54, 95 percent confidence interval [CI], 0.41–0.72). No heterogeneity among trials was observed.

Moreover, the number needed to treat (NNT) was 45 (95 percent CI, 35–74) in order to prevent one case of gastric cancer.

Three trials provided data regarding gastric cancer mortality. Pooled analysis showed that among the 2,242 recipients of eradication therapy, 47 died, with a mortality rate of 2.1 percent. Meanwhile, there was a 3.2-percent death rate among the 2,233 patients receiving placebo or no treatment.

Random effects modelling likewise confirmed that H. pylori eradication significantly lowered the likelihood of gastric cancer mortality by nearly 40 percent (RR, 0.66, 95 percent CI, 0.46–0.95), with an NNT of 92.5 (95 percent CI, 58–629) to prevent one gastric cancer death.

While the present meta-analysis already revealed that eradication therapy was already much more beneficial than previously thought, the researchers pointed out that this effect may even be an underestimate of the true benefits of H. pylori eradication.

Some of the included studies used eradication regiments that were no longer standard clinical recommendations due to suboptimal outcomes, while others eventually offered eradication therapy to participants randomized to placebo or no-treatment arms.

“In others, an increasing proportion of participants in the placebo or no treatment arms tested negative for H. pylori as duration of follow-up increased, suggesting some subjects sought out eradication therapy subsequently,” the researchers added.

Taken together, the findings of the present meta-analysis suggest that eradication therapy is indeed a highly effective method to lower rates of gastric cancer and related deaths.