Hepatitis B virus-associated intrahepatic cholangiocarcinoma and hepatocellular carcinoma may hold common disease process for carcinogenesis

Abstract Aims To evaluate potential risk factors for intrahepatic cholangiocarcinoma (ICC) and analyse clinicopathologic characteristics of ICC patients with seropositive hepatitis B surface antigen (HBsAg). Methods A retrospective case–control study was conducted. Cases were 317 ICC patients referred to the Eastern Hepatobiliary Surgery Hospital in China between 2003 and 2006. Controls were 634 healthy individuals. Adjusted odds ratios (ORs) were calculated in logistic regression analysis. Among 317 consecutively enrolled ICC patients, 154 patients were seropositive HBsAg (48.6%). We compared clinicopathologic characteristics of these patients (group I) with ICC patients seronegative for HBsAg (group II; n =163) and compared the age and sex distributions of patients in group I with randomly selected hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) (group III; n =1140). Results Compared with the controls, ICC patients had a high prevalence of seropositive HBsAg, cirrhosis, hepatolithiasis and hepatic schistosomiasis. Compared with seronegative-HBsAg ICC patients, seropositive-HBsAg ICC patients were younger, more frequently male and had a higher proportion of abnormal aminotransferase and serum alpha-fetoprotein (AFP) level, histological inflammation and cirrhosis, right-lobe focus, poor tumour differentiation, tumour encapsulation and microvascular invasion; had a lower proportion of abnormal serum carbohydrate antigen 19-9 (CA19-9) level and lymphatic metastasis. The age and sex distribution profiles were nearly identical between seropositive-HBsAg ICC patients and HBV-associated HCC patients. Conclusions The HBV infection, cirrhosis, hepatolithiasis and hepatic schistosomiasis may be potential risk factors for ICC. HBV-associated ICC shares many clinicopathological similarities with HBV-associated HCC. The result indicated HBV-associated ICC and HBV-associated HCC may hold common disease process for carcinogenesis.