Bile duct cancer causes and risk factors

This page was reviewed under our medical and editorial policy by

Maurie Markman, MD, President, Medicine & Science.

This page was updated on June 3, 2022.

The bile ducts play a significant role in the proper functioning of the digestive system. Bile duct system problems, such as inflammation, irritation or an obstruction, may cause digestive issues or jaundice or may develop into a chronic (long-lasting) disease. Some of these conditions are considered risk factors for bile duct cancer.

What is cholangiocarcinoma or bile duct cancer?

Bile duct cancer, or cholangiocarcinoma, occurs when cells in the bile duct become damaged or mutated. These damaged cells begin to grow and divide out of control and form a tumor or tumors.

Bile duct cancer (cholangiocarcinoma) is uncommon, accounting for 10 percent to 20 percent of liver cancers. The exact cause of bile duct cancer is not known, but research indicates that inflammation may play a role in altering the cells' DNA, causing cancer to form and grow. Bile duct cancer is not believed to be caused by genetics inherited by family members. There are, however, several risk factors that can increase the risk of developing bile duct cancer.

Bile duct cancer (cholangiocarcinoma) risk factors

Bile duct cancer risk factors include:

Age: More than 60 percent of bile duct cancer patients are 65 years or older.

Ethnicity: Certain ethnic groups have an increased risk of bile duct cancer. In the United States, it’s highest among Hispanic-Americans. People in China and Southeast Asia also face increased risk due to high infection rates from liver flukes, a type of parasite.

Non-alcoholic fatty liver disease (NAFLD): This is a type of disease in which extra fat builds up in the liver cells. It’s not caused by alcohol use. Over time, it may lead to liver swelling and scarring that may potentially become cancerous.

Diabetes: Patients with type 1 and type 2 diabetes have a higher-than-normal risk of bile duct cancer. However, it’s still considered low risk.

Hepatitis infection: Long-term infection with hepatitis B or C virus may increase risk. This is possibly because both viruses may cause cirrhosis of the liver.

Obesity: Being obese may increase the risk of some cancers, including bile duct and liver cancer.

Family history: Although a family history of bile duct cancer may increase a person’s bile duct cancer risks, the risk is low because this is a rare disease. Most cases of bile duct cancer do not appear to be hereditary.

Excessive alcohol use and/or cirrhosis of the liver: Alcohol abuse is a common cause of cirrhosis of the liver, which increases a person’s liver cancer risks.

Smoking: Tobacco use may increase the risk of developing bile duct cancer.

Exposure to hazardous chemicals: Exposure to certain chemicals have been linked to an increased risk of bile duct cancer. These include dioxins, nitrosamines, polychlorinated biphenyls (PCBs), asbestos, radon and thorotrast (thorium dioxide, a radioactive substance previously used as a contrast agent for certain X-rays).

Chronic irritation or inflammation of the bile duct: Some conditions that cause chronic inflammation and increase the risk of bile duct cancer are bile duct stones, ulcerative colitis (inflammation of the gastrointestinal tract) and primary sclerosing cholangitis (PSC), an autoimmune disease that causes inflammation of the bile duct and scarring.

Liver or bile duct diseases: Some diseases of the liver or bile duct, such as polycystic liver disease, pancreatitis (inflammation of the pancreas), irritable bowel syndrome, choledochal cysts (bile-filled sacs outside the liver with pre-cancerous cells) and Caroli’s syndrome (an inherited condition present at birth that causes dilation or widening of the intrahepatic bile ducts), may increase a person’s bile duct cancer risks.

Parasitic infections: A water-borne parasite called liver fluke (Clonorchis sinensis and Opisthorchis viverrini), which is commonly found in some parts of Asia and Europe, may infect the bile duct and cause cancer.

How to lower the risk of bile duct cancer

While it’s not always possible to prevent bile duct cancer, there are a number of steps patients may take to help lower the risk. Below, find a few lifestyle changes that may be possible.

  • Try to remain at a healthy weight and stay physically active.
  • Avoid risky behaviors, such as needle sharing, that may increase the risk of contracting hepatitis C.
  • Prevent risk of hepatitis B by getting vaccinated against it.
  • Limit alcohol consumption, or avoid it completely.
  • Quit smoking.
  • Avoid exposure to chemicals such as asbestos, radon and dioxin.

Next topic: What are the symptoms of bile duct cancer?

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Show references

  • American Cancer Society (2018, 3 July). Bile Duct Risk Factors.
  • American Cancer Society (2020, June 9). Can Bile Duct Cancer Be Prevented?