Risk Factors of Cholangiocarcinoma

Executive Summary

There are several risk factors associated with cholangiocarcinoma. Primary sclerosing cholangitis (PSC), parasite liver infections, chronic liver illness, cognitive liver abnormalities, thorotrast are the common risk factors for cholangiocarcinoma. Primary sclerosing cholangitis (PSC) is the inflammatory illness of the bile ducts associated with ulcerative colitis found in the Western world (UC). The parasite infection linked with liver flukes originated due to raw and undercooked food consumption. Chronic liver illness such as viral hepatitis, alcoholic liver disease, or cirrhosis of the liver owing to other causes puts people at a higher risk of developing cholangiocarcinoma. Thorotrast is related to the development of cholangiocarcinoma 30–40 years after exposure to thorium dioxide, mainly causing risk to the United States.

What are the Risk Factors of Cholangiocarcinoma?

Several risk factors of cholangiocarcinoma have been identified, despite the fact that most persons present with no known risk factors.

Primary sclerosing cholangitis (PSC)

An inflammatory illness of the bile ducts strongly related to ulcerative colitis is the most frequent in the Western world (UC) ^​1​. Epidemiologic research has revealed that a person with PSC has a 10–15 per cent lifetime risk of getting cholangiocarcinoma. However, autopsy studies have shown that this population has rates as high as 30%.

Parasite liver infections

Certain Parasite liver infections could also be a risk factor. Cholangiocarcinoma has been linked to infection with the liver flukes Opisthorchis viverrini (found in Thailand, Lao PDR, and Vietnam) or Clonorchis sinensis (found in China, Taiwan, eastern Russia, Korea, and Vietnam) ^​2​. In some countries, control efforts (Integrated Opisthorchiasis Control Program) targeted at reducing raw and undercooked food consumption have successfully lowered the incidence of cholangiocarcinoma.

Also Read: Diagnostic Approaches

Chronic liver illness

Chronic liver illness such as viral hepatitis (e.g., hepatitis B or C), alcoholic liver disease, or cirrhosis of the liver owing to other causes puts people at a higher risk of developing cholangiocarcinoma ^​3​. HIV infection was also found as a possible risk factor for cholangiocarcinoma in one study. However, it was unclear whether the connection was caused by HIV or other contact and confounding factors (such as hepatitis C). Biliary carcinoma can be caused by the bacteria Helicobacter bilis and Helicobacter hepaticus.

Congenital liver abnormalities

Such as Caroli disease (one of five types of choledochal cysts) has been linked to a 15% lifetime risk of cholangiocarcinoma ^​4​. This tumour has also been linked to the rare genetic illnesses Lynch syndrome II and biliary papillomatosis. Gallstones (cholelithiasis) are not related to the development of cancer. Intrahepatic stones (also known as hepatolithiasis), uncommon in the West but widespread in Asia, have been linked to cholangiocarcinoma.

Thorotrast

A type of thorium dioxide used as a radiologic contrast medium has been related to the development of cholangiocarcinoma 30–40 years after exposure; thorium dioxide was outlawed in the United States in the 1950s due to its carcinogenicity ^​5​.

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