What is Bile Duct Cancer?
The bile duct is a thin tube, about 4 to 5 inches long, that reaches from the liver to the small intestine. The major function of the bile duct is to move a fluid called bile from the liver and gallbladder to the small intestine, where it helps digest the fats in foods.
The bile duct system has different parts. The part near the liver is described as intrahepatic. The two small branches within the liver are called intrahepatic bile ducts. They exit the liver and join to form one duct in an area called the hilum. A third duct extending from the gall bladder, joins the merged duct, developing into one common bile duct. The common bile duct passes through part of the pancreas before emptying into the small intestine.
Bile duct cancers have different names, depending on where they develop.
Intrahepatic Bile Duct Cancers - These cancers develop in the smaller bile duct branches inside the liver.
Extrahepatic Bile Duct Cancers - These develop outside of the liver. There are two main types:
Perihilar Bile Duct Cancers develop at the hilum, where the two smaller branches leave the liver and merge into one duct. They are also called Klatskin tumors. These are the most common type of bile duct cancer.
Distal or Distal Extrahepatic Bile Duct Cancers are found further down the duct, closer to the small intestine.
More than 95% of bile duct cancers are adenocarcinomas, which means they start in glandular cells. Bile duct adenocarcinomas develop from the mucus glands that line the inside of the duct.
Research is improving our understanding of bile duct cancer and its causes. The following are known risk factors for the disease:
Liver Diseases: Having colitis or certain liver diseases can increase the risk of developing extrahepatic bile duct cancer. These include:
- Primary sclerosing cholangitis
- Chronic ulcerative colitis
- Choledochal cysts
- Infection with a Chinese liver fluke parasite
Signs and Symptoms
These symptoms may be caused by bile duct cancer or by other conditions. Consult a doctor if any of the following occur:
- Jaundice (yellowing of the skin or whites of the eyes)
- Pain in the abdomen
- Itchy skin
The diagnosis of bile duct cancer requires a physical exam. Once you learn the results of the tests or procedures, you will be able to work with your health care team to make thoughtful decisions. Some of the tests that you may undergo as doctors determine if you have bile duct cancer include:
- Physical Exam – A doctor will collect information on your health history and habits, take your temperature and blood pressure and check for signs of disease, such as lumps or anything else unusual.
- Ultrasound Exam - A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram.
- CT Scan - Detailed pictures of areas inside the body are taken from different angles. A dye may be swallowed or injected into a vein to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography or computerized axial tomography.
- MRI - A procedure that uses a magnet, radio waves and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).
- ERCP (Endoscopic Retrograde Cholangiopancreatography) – A procedure to x-ray the ducts that carry bile to and from the gallbladder. An endoscope is passed through the mouth, esophagus and stomach into the small intestine. A smaller tube is then inserted through the endoscope. A dye is injected through the smaller tube into the ducts and the x-ray is taken.
- PTC (Percutaneous Transhepatic Cholangiography) - A procedure to x-ray the liver and bile ducts. A thin needle is inserted through the skin below the ribs and into the liver. Dye is injected into the liver or bile ducts and an x-ray is taken. If a blockage is found, a thin, flexible tube called a stent is sometimes left in the liver to drain bile into either the small intestine or a collection bag outside the body.
- Biopsy – A sample of cells or tissues is removed and viewed under a microscope to check for signs of cancer. The sample may be taken using a thin needle inserted into the duct during an x-ray or ultrasound. This is called a fine-needle aspiration biopsy (FNA.) The biopsy is usually done during PTC or ERCP.
- Liver Function Tests - A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by the liver. A higher than normal amount of a substance can be a sign of liver disease that may be caused by extrahepatic bile duct cancer.
If cancer is diagnosed, the doctor needs to know the stage, or extent, of the disease to determine the best treatment. Staging is used to find out whether the cancer has spread, and if so, to which parts of the body.
The following stages are used for extrahepatic bile duct cancer:
Stage 0 (carcinoma in situ)
In stage 0, abnormal cells are found in the innermost layer of tissue lining the extrahepatic bile duct. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.
In stage I, cancer has formed. Stage I is divided into stage IA and stage IB.
- Stage IA - The cancer is found in the bile duct only.
- Stage IB - The cancer has spread through the wall of the bile duct.
Stage II is divided into stage IIA and stage IIB.
- Stage IIA - Cancer has spread to the liver, gallbladder, pancreas or to either the right or left branch of either the hepatic artery or to the right or left branch of the portal vein.
- Stage IIB - Cancer has spread to nearby lymph nodes, through the wall of the bile duct or has spread to the liver, gallbladder, pancreas or to the right or left branch of either the hepatic artery or the portal vein.
In stage III, cancer has spread to the main portal vein, both its branches, or to the hepatic artery or other nearby organs or tissues, such as the colon, stomach, small intestine or abdominal wall. Cancer may have spread to nearby lymph nodes.
In stage IV, cancer has spread to lymph nodes and other distant organs.
Your treatment options depend on the stage of cancer, your overall health and your preferences about treatment. In metastatic disease, the location and extent of the bile duct cancer is also important. In all cases, treatment should be individualized for you. Although cancers are classified into particular stages, each person is unique.
Keep these tips in mind as you discuss treatment:
- Take your time. Consider your treatment options carefully. Seek a second opinion if needed.
- Ask questions. Ask your doctor to say something again or explain a medical term. Research shows that people of all educational levels and backgrounds can have a hard time communicating with their health care team.
- Ask about clinical trials. Clinical trials can offer the opportunity to benefit from the latest treatments or combinations of treatments while helping advance knowledge of the disease and its treatment options.
- Prepare for visits. Improve communication by writing down questions in advance. Plan to take notes. Consider bringing a friend or family member to take notes for you.
- Make a treatment plan. Focus on both the short- and long term goals of managing your cancer. Talk through the options and develop a treatment plan that best fits your needs.