Cholangiocarcinoma in USA- versus Asian-born Asians: Is viral hepatitis a factor?

Aim: Though liver and biliary tract cancers are more common in Asian countries they are increasing in incidence in the USA. This study attempted to clarify the risk factor profile for immigrant Asians compared with the USA population. Methods: A retrospective review was made of 128 cholangiocarcinoma cases presenting to a tertiary referral center from 1996-2007. Data were collected on patient characteristics, risk factors, tumor characteristics, treatment and survival. We then compared Asian immigrants (n = 40) to USA-born Asians (n = 46). Results: In our cohort, the mean age was 66.7 years, of whom 54% were men, 51% had cholelithiasis, 51% were smokers, 41% used alcohol, 10% had hepatitis C and 27% had hepatitis B. In four patients, one each had sclerosing cholangitis, liver flukes, choledochal cyst and previous biliary tract surgery. The distribution of tumors was as follows: 43 intrahepatic (ICC) and 85 extrahepatic cholangiocarcinoma (ECC) including 43 proximal, nine middle and 33 distal tumors. Immigrants were more likely to be younger (mean age 63 vs 70years old) and to have ICC than ECC (50% vs 26%) and hepatitis B (46% vs 14%). There was no significant difference between groups in hepatitis C, smoking, alcohol, cholelithasis, resectability or survival. Conclusion: Traditionally described risk factors for cholangiocarcinoma are not as evident in this largely Asian cohort. Asian immigrants were more likely to have ICC and have hepatitis B though whether hepatitis B is directly carcinogenic to the biliary tract is not clear. Immigrant status did not seem to have an effect on outcome from cholangiocarcinoma.