Effectiveness of Helicobacter pylori eradication in preventing metachronous gastric cancer and preneoplastic lesions. A systematic review and meta-analysis

Background: Helicobacter pylori is a significant risk factor for gastric cancer. Recent trials show eradication decreases the incidence of gastric cancer in patients with early-stage gastric cancer. However, data on gastric cancer prevention are inconsistent for patients with precancerous lesions such as atrophic gastritis and intestinal metaplasia. Aim: The aim of the study is to assess the efficacy of H. pylori eradication in gastric cancer prevention in patients with varying risk factors for gastric cancer at baseline. Methods: A systematic review and meta-analysis were performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. PubMed, Medline, and Google Scholar were searched from inception through March 2019 for randomized controlled trials (RCTs) studying H. pylori eradication on gastric cancer prevention. We estimated the odds ratio (OR) with 95% confidence interval (CI) for each outcome using a random-effects model. P values of less than 0.05 were considered significant. Results: Nine RCTs with total of 6967 patient were included in the analysis. There was significant reduction in gastric cancer incidence in the H. pylori group for patients with early gastric cancer status post endoscopic mucosal resection OR, 0.47; 95% CI, 0.33–0.67; P < 0.0001; I 2 = 0%. There was no difference in gastric cancer incidence in patients with atrophic gastritis and intestinal metaplasia at baseline for H. pylori arm OR, 0.67; 95% CI, 0.42–1.07; P = 0.09; I 2 = 0%). Atrophic gastritis and intestinal metaplasia improved from baseline in the H. pylori arm compared to placebo OR, 2.61; 95% CI, 1.41–4.81; P = 0.002; I2 = 88 and OR, 2.61; 95% CI, 1.66–4.11; P ≤ 0.0001; I 2 = 0%, respectively. Conclusions: H. pylori eradication is associated with reduced gastric cancer incidence in patients with early-stage gastric cancer and improvement in atrophic gastritis and intestinal metaplasia. There was no difference in gastric cancer incidence in patients with atrophic gastritis and intestinal metaplasia at baseline.