Rare occurrence of metastatic colorectal cancers in livers with replicative hepatitis B infection

Background: It has been demonstrated that colorectal carcinomas rarely metastasize to diseased livers. However, this phenomenon has not been thoroughly evaluated in patients with various forms of chronic hepatitis B virus (HBV) infection. Therefore, the present study examined the relationship between the incidence of hepatic metastasis of colorectal carcinomas and chronic HBV infection, with emphasis on the influence of HBV viral replication and chronic liver damage. Methods: We analyzed the clinicopathological data of 512 patients undergoing surgical treatment of colorectal carcinomas at our department from 1992 to 1998. Among these cases, 74 had chronic HBV infection, including 28 cases with HBV replication and 21 with chronic liver damage. Results: The incidence of liver metastasis in the HBV infection group (13.5%) was significantly lower than that of the noninfection group (27.1%, P <0.05). In addition, patients with HBV infection survived longer than those without infection (P = 0.018). Furthermore, liver metastatic rate in patients with HBV replication (3.6%) was lower than those without virus replication (19.6%, P <0.05). In contrast, there was no significant difference in liver metastasis between HBV infected patients with or without chronic liver damage (P >0.05). Conclusions: Chronic HBV infection with viral replication reduces hepatic metastasis of colorectal cancer, and thus prolongs the survival of patients.