Known also as cholangiocarcinoma, bile duct cancer occurs when the bile ducts, which carry bile from the liver and gallbladder to the small intestine, are affected. The bile fluid is responsible for digesting fats and removing waste products from the body. It can affect the liver, small intestine, or outer liver. The bile ducts are either located in the liver (intrahepatic), outside the liver (extrahepatic), or outside the liver (distal) .
The exact cause of bile duct cancer is unknown, but some factors may increase the risk of developing it. These include:
Chronic inflammation or infection of the bile ducts, such as primary sclerosing cholangitis (PSC), a condition that causes scarring and narrowing of the bile ducts
Liver diseases, such as cirrhosis, hepatitis B or C, or liver fluke infection, a parasitic disease common in some parts of Asia
Age, as most cases of bile duct cancer occur in people over 50 years old
Smoking, which may damage the DNA of the bile duct cells
Obesity, which may increase the pressure on the bile ducts and cause inflammation
Exposure to certain chemicals, such as asbestos, dioxins, or thorium dioxide, which may be carcinogenic
Family history, as some genetic mutations may predispose to bile duct cancer
Bile duct cancer may not cause any symptoms in the early stages, but as it grows or spreads, it may cause:
Jaundice, which is yellowing of the skin and eyes due to the buildup of bilirubin, a pigment in bile
Itching, which is caused by the irritation of the skin by bilirubin
Abdominal pain, which may be felt on the right side, under the ribs, or in the upper abdomen
Weight loss, which may be due to loss of appetite, nausea, or malabsorption of nutrients
Fever, which may indicate infection or inflammation
Dark urine and pale stools, which may result from the reduced flow of bile into the intestine
Enlarged liver or gallbladder, which may be felt as a lump or mass in the abdomen
To diagnose bile duct cancer, the doctor may perform a physical examination and ask about the medical history and symptoms. The doctor may also order some tests, such as:
Blood tests, to check the liver function and the level of a tumor marker called CA 19-9, which may be elevated in bile duct cancer
Imaging tests, such as ultrasound, CT scan, MRI, or MRCP, to visualize the bile ducts and look for any tumors or blockages
Endoscopic tests, such as ERCP or EUS, to examine the bile ducts with a camera and take a biopsy, which is a sample of tissue for microscopic analysis
Biopsy, to confirm the diagnosis and determine the type and grade of the cancer
The treatment of bile duct cancer depends on the location, size, stage, and type of the cancer, as well as the overall health and preferences of the patient. The main treatment options are:
Depending on the extent of the cancer, surgery may be required to remove the tumor and some surrounding tissue, as well as the liver or gallbladder. A surgical procedure may also be used to unblock bile ducts and restore bile flow. Surgery may cure some cancers at an early stage, but may not be able to cure cancers that are advanced or widespread.
In radiation therapy, high-energy beams are used to kill cancer cells or shrink tumors. A radioactive substance placed near the tumor can be used to deliver radiation therapy before or after surgery, or as a palliative treatment to relieve symptoms. Radiation therapy may be delivered externally or internally.
Chemotherapy involves using drugs to kill cancer cells or stop them from growing. Chemotherapy may be given before or after surgery, or as a palliative treatment to relieve symptoms. Chemotherapy can be administered intravenously, orally, or directly into the bile ducts or the liver.
Some types of bile duct cancer that have certain genetic mutations or markers, such as HER2 or FGFR2, may respond to targeted therapy.
Certain types of bile duct cancer that have certain genetic mutations or markers, such as MSI-H or dMMR, may benefit from immunotherapy.
Palliative care includes pain management, nutritional support, emotional support, and complementary therapies to alleviate the symptoms and side effects of cancer.
There is no sure way to prevent bile duct cancer, but some steps may help reduce the risk or detect it early. These include:
Getting vaccinated against hepatitis B virus, which can cause liver damage and increase the risk of bile duct cancer
Treating hepatitis infections and liver diseases, which can cause inflammation and scarring of the bile ducts and increase the risk of bile duct cancer
Quitting smoking, which can damage the DNA of the bile duct cells and increase the risk of bile duct cancer
Maintaining a healthy weight, which can reduce the pressure on the bile ducts and prevent inflammation
Avoiding exposure to certain chemicals, such as asbestos, dioxins, or thorium dioxide, which may be carcinogenic
Having regular check-ups and screening tests, especially for people who have a family history or a high-risk condition, such as PSC, liver fluke infection, or ulcerative colitis
As a rare and serious form of cancer, bile duct cancer requires prompt diagnosis and treatment. By being aware of the symptoms, causes, and risk factors, and by following the prevention tips, one may be able to lower the risk of developing bile duct cancer or catch it earlier, when it is more treatable.
