Helicobacter pylori Infection and Risk of Lung Cancer: A Meta-Analysis

Background . Recent evidence showed that Helicobacter pylori seropositivity is a risk factor for gastric and several other cancers. However, evidence on H. pylori infection and risk of lung cancer has been controversial, with a limited number of underpowered studies. We therefore examined the association between H. pylori infection and risk of lung cancer. Methods . A comprehensive literature search was performed using PubMed, EMBASE (until October 2012) for studies investigating an association between Helicobacter pylori ( H. pylori ) infection and risk of lung cancer. Pooled odds ratio (OR) was calculated using random-effects model. Subgroup and sensitivity analysis were also done. Results . A total of seven studies (6 case-control and 1 cohort study) were included for the analysis. There was a significant heterogeneity among the studies, but no publication bias was observed. We found that H. pylori infection was associated with significantly increased risk of lung cancer (pooled OR, 2.29 (95% CI, 1.34–3.91) P = 0.01). Conclusions . Our meta-analysis suggests a significant increased risk of lung cancer in patients with H. pylori infection. Further research is needed to confirm these findings and to identify the underlying biological mechanisms.