Bile duct cancer risk factors: who is more likely to get it

What bile duct cancer is

Bile is a fluid the liver makes to break down fats during digestion. A network of tubes, the bile ducts, carries it from the liver and gallbladder to the small intestine. Bile duct cancer is a rare disease in which cancer cells form in these ducts (NCI). MedlinePlus also calls it rare (MedlinePlus).

NCI describes two types (NCI):

• Intrahepatic bile duct cancer forms in the ducts inside the liver. Only a small number of bile duct cancers are this type.
• Extrahepatic bile duct cancer forms in the ducts outside the liver. It is split into perihilar cancer (where the right and left ducts leave the liver, also called a Klatskin tumor) and distal cancer (near where the common bile duct passes through the pancreas).

NCI's health professional summary says about 50% of these cancers start in the perihilar region, 40% in the distal region and 10% inside the liver, and that the true number of cases is unknown because an accurate diagnosis is hard to make (NCI PDQ HP). MedlinePlus also says cancer of the ducts outside the liver is much more common (MedlinePlus).

Who is more likely to get bile duct cancer

NCI lists these conditions as risk factors (NCI):

• Primary sclerosing cholangitis, a progressive disease in which the bile ducts become blocked by inflammation and scarring.
• Chronic ulcerative colitis.
• Cysts in the bile ducts. Cysts block the flow of bile and can cause swollen bile ducts, inflammation and infection.
• Infection with a Chinese liver fluke, a parasite. The health professional summary names it as Clonorchis sinensis (NCI PDQ HP).

MedlinePlus sums up the risk factors as inflammation of the bile duct, ulcerative colitis and some liver diseases (MedlinePlus). See also our cirrhosis risk factors guide.

NCI adds that not everyone with one or more of these risk factors will get bile duct cancer, that it develops in some people who have no known risk factor, and that people who think they may be at risk should talk with their doctor (NCI). The NCI and MedlinePlus pages we use do not list further risk factors, so we do not add any here.

Screening and diagnosis

NCI says there are no routine screening tests for bile duct cancer before signs and symptoms appear (NCI).

To diagnose it, doctors may use a physical exam and health history, liver function tests, CEA and CA 19-9 tumor marker blood tests, and imaging such as ultrasound, CT, MRI or MRCP (an MRI of the liver, bile ducts, gallbladder and pancreas). A biopsy, a tissue sample checked under a microscope, may be taken during laparoscopy, a needle procedure through the skin into the liver (PTC), ERCP or endoscopic ultrasound (NCI). MedlinePlus lists the same main steps: a physical exam, imaging of the liver and bile ducts, blood tests and a biopsy (MedlinePlus).

Why it is often found late

NCI says bile duct cancer is usually found after it has spread and can rarely be completely removed by surgery. Palliative therapy may relieve symptoms and improve quality of life (NCI). Treatments include surgery, radiation therapy and chemotherapy (MedlinePlus).

Common questions

Is bile duct cancer the same as gallbladder or liver cancer?

No. It starts in the bile ducts. Cancer of the ducts inside the liver used to be grouped with primary liver tumors, and cancer of the ducts outside the liver with gallbladder cancer, but bile duct tumors are now classed on their own as intrahepatic or extrahepatic (NCI PDQ HP). See our gallbladder cancer and liver cancer risk factor guides.

I have ulcerative colitis. Will I get bile duct cancer?

Not necessarily. Chronic ulcerative colitis is a listed risk factor, but NCI says not everyone with a risk factor will develop the disease. If you think you may be at risk, talk with your doctor (NCI).

What are the first signs?

Cancers outside the liver often block bile flow, which leads to jaundice, weight loss, abdominal pain, fever and itching. Cancer inside the liver may grow slowly and be hard to tell apart from other tumors in the liver (NCI PDQ HP). See the full list of signs in the box at the top of this page.

Also see gallstones risk factors and pancreatic cancer risk factors.