Approximately two-thirds of cholangiocarcinomas occur in patients ages between 50 and 70 years, with a slight male predominance.[4]Carriaga MT, Henson DE. Liver, gallbladder, extrahepatic bile ducts, and pancreas. Cancer. 1995;75:171-190.
http://www.ncbi.nlm.nih.gov/pubmed/8000995?tool=bestpractice.com
The reported incidence of biliary tumors has increased in recent years; however, the increase is probably due to improvement in data collection and analysis.
The incidence varies worldwide. The highest known rates occur in north-east Thailand (>80 per 100,000 population).[2]Bridgewater J, Galle PR, Khan SA, et al. Guidelines for the diagnosis and management of intrahepatic cholangiocarcinoma. J Hepatol. 2014;60:1268-1289.
http://www.journal-of-hepatology.eu/article/S0168-8278%2814%2900067-1/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/24681130?tool=bestpractice.com
High rates of biliary cancer are also seen in South American countries (Bolivia, Chile) and northern Japan. Intermediate rates are seen in many European countries, and low rates are observed in the US, the UK, India, Nigeria, and Singapore.[5]Levin B. Gallbladder carcinoma. Ann Oncol. 1999;10(suppl 4):129-130.
http://www.ncbi.nlm.nih.gov/pubmed/10436804?tool=bestpractice.com
The lowest rates are seen in Canada (0.3 per 100,000).[2]Bridgewater J, Galle PR, Khan SA, et al. Guidelines for the diagnosis and management of intrahepatic cholangiocarcinoma. J Hepatol. 2014;60:1268-1289.
http://www.journal-of-hepatology.eu/article/S0168-8278%2814%2900067-1/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/24681130?tool=bestpractice.com
In the US, New Mexico has the highest incidence of biliary tree carcinoma (gallbladder carcinoma accounts for 8.5% of all cancers).[6]Pitt HA, Dooley WC, Yeo CJ, et al. Malignancies of the biliary tree. Curr Probl Surg. 1995;32:1-90.
http://www.ncbi.nlm.nih.gov/pubmed/7528652?tool=bestpractice.com