The part of the bile duct that is outside the liver is called the extrahepatic bile duct. Bile, a fluid made by the liver that breaks down fats during digestion, is stored in the gallbladder. When food is being broken down in the intestines, bile is released from the gallbladder through the bile duct to the first part of the small intestine.
Several different tests may be utilized to detect bile duct cancer. These may include an ultrasound (a test that uses sound waves to create an image or picture of something internal), a CT (a computerized tomographic) scan, a special type of x-ray that uses a computer to make a picture of the inside of the abdomen) and an MRI (magnetic resonance imaging which uses a magnet to make a picture of the inside of the abdomen).
A test called an ERCP (endoscopic retrograde cholangiopancreatography) may be done. A flexible tube is put down the throat, through the stomach, and into the small intestine to where the bile ducts connects to the intestine. Radiographic dye can then be injected into the bile duct system.
PTC (percutaneous transhepatic cholangiography) is another test that can help find cancer of the extrahepatic bile duct. During this test, a thin needle is put into the liver through the right side of the patient. Dye is injected through the needle into the bile duct in the liver so that blockages can be seen on x-rays.
If an abnormal area is found on those tests, the doctor may remove a small amount of fluid or tissue from the bile duct and look at it under the microscope for cancer cells. This biopsy procedure is usually done during the ERCP.
Because it is sometimes hard to tell whether a patient has cancer or another disease, surgery may be needed. If extrahepatic bile duct cancer is found, further tests are done to see if the cancer cells have spread to other parts of the body. This is called staging the cancer. The stage of the cancer is important to the treatment plan and prognosis (outlook). The following stages are commonly used for extrahepatic bile duct cancer:
- Localized: The cancer is only in the area where it began and it can be removed by surgery.
- Unresectable: The cancer cannot be completely removed (resected) by surgery. The cancer may have spread to nearby organs and lymph nodes or to other parts of the body.
- Recurrent: This means the cancer has come back (recurred) after it has been treated. It may come back in the bile duct or in another part of the body.
The treatments for bile duct cancer include: surgery (taking out the cancer or taking steps to relieve symptoms caused by the cancer), radiation therapy (using high-dose x-rays to kill the cancer cells); and chemotherapy (using drugs to kill cancer cells).
The chances of recovery and the choice of treatment depend on the location of the cancer in the bile duct, the stage of the cancer and the patient's general health. Cancer arising in the extrahepatic bile duct is an uncommon disease. It is curable by surgery in fewer than 10% of all cases. The prognosis depends in part on the exact anatomic location of the tumor, which affects its resectability. Total resection is possible in 25% to 30% of cases in which the tumor arises in the distal bile duct, a resectability rate that is clearly better than for tumors that occur in more proximal sites. Bile duct cancer may occur more frequently in patients with a history of primary sclerosing cholangitis, chronic ulcerative colitis, choledochal cysts, or infections with the fluke Clonorchis sinensis. The most common symptoms of bile duct cancer are jaundice, pain, fever, and pruritus. In most patients, the tumor cannot be completely removed by surgery and is incurable. Palliative resections or other palliative measures such as irradiation (e.g., brachytherapy or external-beam radiation therapy) or stenting procedures may maintain adequate biliary drainage and allow for improved survival. Many bile duct cancers are multifocal. Perineural invasion has a negative impact on survival.