Relationship between hepatitis B virus infection and hepatic metastasis from colorectal cancer: a Meta analysis

Objective To investigate the relationship between hepatitis B virus (HBV) infection and hepatic metastasis from colorectal cancer. Methods Published literatures and unpublished conference papers from January 1990 to December 2011 were searched in PubMed, Cochrane library, Wanfang Database and CNKI. Data of the literatures were extracted by a table. All the patients with colorectal cancer were divided into the infected group and the control group according to the patients whether infected by HBV or not. The hepatic metastatic rate was analyzed. The Meta analysis was carried out by using the Review Manager 5.0 software, and the heterogeneity between studies was analyzed using the I₂. Random effect regression model or fixed effects regression model was used according to the P value. The funnel plot was drawn to assess the potential for publication bias. The count data were presented by odds ratio (OR) and 95% confidence intervals (95% CI). Results Fiftysix articles were retrieved, and 11 of which met the criteria. The number of patients with colorectal cancer was 5622, and 924 were in the infected group, 4698 in the control group. There was no statistical difference in the heterogeneity between all the articles (I₂=0, df=10, P>0.05). The hepatic metastatic rate was 10.61% (98/924) in the infected group, which was significantly lower than 23.84% (1120/4698) of the control group (OR=0.35, P<0.05). The funnel plot showed that there was no obvious publication bias in these studies. Conclusion Patients with colorectal cancer and infected by HBV have lower incidence of hepatic metastasis.