HBV infection decreases risk of liver metastasis in patients with colorectal cancer：A cohort study

AIM：To evaluate the effect of hepatitis B virus （HBV） infection on liver metastasis of colorectal cancer.METHODS：A total of 1298 colorectal cancer patients were recruited from January 2001 to March 2005 in this study.Enzyme-linked immunosorbent assay was used to test serum HBV markers for colorectal cancer.Patients were divided into study （infection） group and control （non-infection） group.Clinical features of patients in two groups were compared.RESULTS：Liver metastasis was found in 319 out of the 1298 colorectal cancer patients.The incidence of liver metastasis was significantly lower in study group than in control group （14.2% vs 28.2%,P 0.01）.HBV infection significantly decreased the risk of liver metastasis [hazard ratio （HR）：0.50,95% confidence interval （95% CI）：0.38-0.66],but the incidence of extrahepatic metastasis was significantly higher in study group than in control group （31.9% vs 17.0%,P 0.01）.The HR was the lowest in chronic hepatitis B group （HR：0.29,95% CI：0.12-0.72）.The number of liver metastatic lesions was significantly less in study group than in control group with a higher surgical resection rate.However,no significant difference was found in survival rate between the two groups （P=0.95）.CONCLUSION：HBV infection decreases the risk of liver metastasis in patients with colorectal cancer and elevates the surgical resection rate of liver metastatic lesions.