Evaluation of risk factors and clinicopathologic features for intrahepatic cholangiocarcinoma in Southern China: a possible role of hepatitis B virus.

Background: Recent efforts suggest an etiologic role of hepatitis B virus (HBV) infection in intrahepatic cholangiocarcinoma (ICC) and the involvement of hepatic progenitor cell in ICC development, without definitive conclusions. This case-control study was undertaken to investigate risk factors for ICC, and clinicopathological features of HBV-associated ICC were analyzed.
Methods: The report comprised 98 patients with pathologically confirmed ICC and 196 healthy control subjects. Logistic regression was used to determine odds ratios and 95% confidence intervals. The sex and age distributions of HBV-related and unrelated ICC patients were compared respectively with those of 882 HBV-associated hepatocellular carcinoma patients from a random selection, and the clinicopathological data of 62 ICC patients with or without HBV infection undergoing surgical resection were compared.
Results: There was an association between ICC and each of HBV infection, liver cirrhosis, hepatolithiasis, and liver fluke infestation with the odds ratios (95% confidence intervals) of 2.75 (1.27-5.95), 8.42 (2.50-28.37), 22.81 (7.16-72.68), and 3.55 (1.60-7.89), respectively, with a marked synergism of cirrhosis and HBV infection (20.67; 5.40-79.06). Compared with HBV-unrelated ICC patients, HBV-related ICC patients were more common in male and younger subjects, had a higher incidence of abnormal serum alfa-fetoprotein level, cirrhosis, and neutrophilic infiltration, and had a lower proportion of elevated carbohydrate antigen 19-9 (CA19-9) values.
Conclusions: The independent association of HBV infection with ICC, synergy between cirrhosis and HBV infection, and some clinicopathological similarities between HBV-related ICC and hepatocellular carcinoma suggests that both may share similar or common tumorigenic process and may possibly originate from malignant transformation of hepatic progenitor cell.