Bile Duct Cancer (Cholangiocarcinoma) Explained

Bile ducts are thin tubes. They carry bile from the liver and gallbladder into the small intestine, where bile helps digest fat. Bile duct cancer, also called cholangiocarcinoma, starts in the cells lining these tubes. It is rare. Nearly all cases are adenocarcinomas, a type that starts in gland cells.

Doctors classify bile duct cancer by where it starts, because location affects symptoms, treatment, and surgical options.

• Intrahepatic cancer starts in the smaller bile duct branches inside the liver itself. It makes up about 1 in 10 cases.
• Perihilar cancer, sometimes called a Klatskin tumor, starts where the ducts from the left and right sides of the liver join together.
• Distal cancer starts farther along the bile duct, closer to where it passes through the pancreas and empties into the small intestine.

Several conditions that damage or inflame the bile ducts raise cancer risk over time:

• Primary sclerosing cholangitis, a disease that inflames the bile ducts and causes scar tissue to form.
• Bile duct stones and choledochal cysts, both of which cause long-term irritation in the ducts.
• Liver fluke infection, caught from eating undercooked fish, a major reason bile duct cancer is far more common in parts of Southeast Asia and China.
• Cirrhosis and chronic hepatitis B or C infection.
• Inflammatory bowel disease, including ulcerative colitis and Crohn's disease.
• Inherited conditions, including Lynch syndrome and cystic fibrosis.

Diabetes, obesity, and older age also raise risk, most cases occurring in people in their sixties and seventies. Having a risk factor does not mean you will get bile duct cancer. Many people diagnosed have no clear risk factor at all.

Bile duct cancer often causes no symptoms until a tumor grows large enough to block bile flow. Once that happens, symptoms tend to appear together:

• Jaundice, a yellowing of the skin and eyes, from bile backing up into the bloodstream.
• Itching, caused by the same buildup in the skin.
• Pale, greasy, bulky stools, because bile is not reaching the intestine.
• Dark urine, as the body tries to remove the excess through the kidneys instead.
• Pain below the right ribs, appetite loss, weight loss, and sometimes fever.

These symptoms are far more often caused by something other than bile duct cancer, most commonly gallstones or hepatitis. Even so, jaundice always needs prompt medical evaluation. It points to a problem, most often in the liver or bile ducts, that needs to be identified.

Surgery to remove the tumor offers the best chance of cure. It is only possible when the cancer is caught before it has spread too far. The location also has to allow a surgeon to safely reach it. Perihilar and distal tumors often sit near major blood vessels. That makes them harder to remove completely than smaller intrahepatic tumors.

Some cancer cannot be fully removed. For that, treatment usually combines chemotherapy with targeted therapy or immunotherapy. The combination depends on specific features found through testing the tumor. Radiation can help control local growth. A stent can relieve a blocked bile duct, even when cure is not possible. This can meaningfully ease symptoms and improve day-to-day comfort.

• Which type of bile duct cancer do I have, based on its location?
• Is surgery possible for my tumor, and what would it involve?
• Has my tumor been tested for specific genetic features that could guide targeted therapy?
• If a cure is not possible, what can be done to relieve symptoms like jaundice or itching?

• American Cancer Society — What Is Bile Duct Cancer?
• American Cancer Society — Bile Duct Cancer Risk Factors
• American Cancer Society — Signs and Symptoms of Bile Duct Cancer