Аннотация:OBJECTIVE: As conflicting studies have recently been published, we aimed to determine if Helicobacter pylori (H. pylori) infection is associated with gastric adenocarcinoma. METHODS: This was a meta-analysis of observational epidemiological studies. RESULTS: A total of 42 studies met the selection criteria and were categorized by the type of study design: eight cohort and 34 case-control studies. The pooled odds ratio for H. pylori in relation to gastric carcinoma was 2.04 (95% CI: 1.69–2.45). Both patient age (OR 0.77, 95% CI: 0.68–0.89) and intestinal type cancers (OR 1.14, 95% CI: 1.05–1.25) were independent effect modifiers. Analysis of other effect modifiers showed no relationship with female gender (OR 0.76, 95% CI: 0.64–0.89), stage of cancer (advanced %) (OR 1.12, 95% CI: 0.88–1.43), anatomical location (cardia %) (OR 1.54, 95% CI: 0.32–7.39) or cohort (nested case-control) studies (OR 1.72, 95% CI: 0.32–9.17). There was significant heterogeneity among the studies (τ2= 149; p < 0.001). The quality of the studies varied considerably, with the majority of excellent studies producing positive results and the very poor to moderate studies producing mixed results. CONCLUSIONS: H. pylori infection is associated with a 2-fold increased risk of developing gastric adenocarcinoma.