Objective: As Helicobacter spp. have been successfully isolated from the biliary system, a hypothetical question was raised about the role of these organisms in the development of biliary tract cancer. This meta-analysis has been carried out to explore the association between Helicobacter spp. infection and biliary tract cancer.
Methods: A systematic literature search was carried out to identify all eligible articles. Meta-analysis used odds ratio and a random-effect model, and 95% confidence intervals for odds ratios were calculated. Heterogeneity was quantitatively assessed using the χ-test, with significance set at a P-value of 0.01, and was measured using the I-statistic.
Results: Ten studies published between 2002 and 2011 were finally included for meta-analysis. Helicobacter pylori, Helicobacter bilis, Helicobacter hepaticus, and Helicobacter ganmani were studied. With heterogeneity (I=0%, P=0.685), a significantly higher pooled infection rate of Helicobacter spp. was observed in the biliary tract cancer group compared with the normal group (P=0.0001) and the benign biliary disease group, respectively (P=0.0001). Studies from East Asia and South Asia showed a higher prevalence of Helicobacter spp. in the malignant group. Evidence supporting the higher presence of Helicobacter spp. in the cancer group was obtained using PCR and immunohistochemical analysis of specimens from bile and biliary tissues.
Conclusion: Our meta-analysis suggests a trend of a higher presence of Helicobacter spp. in patients with biliary tract cancers compared with normal controls or those with benign biliary diseases.