Evaluation of risk factors for extrahepatic cholangiocarcinoma: ABO blood group, hepatitis B virus and their synergism

Abstract

Little is known about the role of association between ABO blood group and development of extrahepatic cholangiocarcinoma (ECC) through effects on hepatitis B viral (HBV) infection. Our aim was to address this question using a matched case-control study in Southern China.We prospectively analyzed 239 ECC patients, and 478 age- and sex-matched controls in Sun Yat-sen Memorial Hospital of Sun Yat-sen University from 1999 to 2011. Information on ABO blood group, HBV infection and other clinicopathologic factors was collected. Adjusted odds ratios (AORs) and the corresponding 95% confidence intervals (CIs) were computed from unconditional logistic regression models, adjusted for major confounding factors. The estimated AORs were as follows: A blood group, 1.784; HBsAg+/HbcAb+, 1.848 and HBsAg-/HbcAb+, 1.501. The A blood type had a significant effect on modifying the risk of ECC among subjects with HBsAg+/HbcAb+ (AOR 3.795, 95% CI 1.427-10.090). ECC patients with A blood group were more common in younger subjects, and a lower proportion of serum CA-125 and CA19-9 elevation in patients with blood type A was found. Our study suggests an association between A blood type, HBV infection and ECC risk, and a synergism between A blood type and HBV infection in the development of ECC. What's new? Hepatitis B virus (HBV) infection is a suspected risk factor for extrahepatic cholangiocarcinoma (ECC), though how it gives rise to malignant disease of the bile ducts situated outside the liver is unclear. Here, a significant association was found for HBV infection, A blood type, and ECC risk in the Han Chinese ethnic group of Southern China. Compared with non-A blood group ECC patients, type A ECC patients tended to be younger and had lower CA-125 and CA19-9 levels. The study is the first to confirm an association between A blood group, HBV, and ECC risk. Copyright © 2013 UICC.