The Biliary System
The bile ducts are the tubes connecting the liver and gall bladder to the small intestine (small bowel). Bile is a fluid made by the liver and stored in the gall bladder. Its main function is to break down fats during their digestion in the small bowel. In people who have had their gall bladder removed, bile flows directly into the small intestine. The bile ducts and gall bladder are known as the biliary system.
Bile Duct Cancer
The terms cholangiocarcinoma and bile duct cancer are often used interchangeably. Primary biliary tract malignancies affect one in every 100,000, or 4600 people per year in the United States. More than 95% of these malignancies are cholangiocarcinomas frequently found in the extrahepatic biliary tree. This form of cancer is slightly more prevalent in males than females (1.3 to 1.0) and usually affects patients in the fifth to seventh decade of life.
Causes and Risk Factors
The cause of most bile duct cancers is unknown. There are a number of risk factors that can increase your risk of developing bile duct cancer. These are:
Inflammatory Bowel Disease ~ People who have a chronic inflammatory bowel condition, known as ulcerative colitis, are at an increased risk of developing this type of cancer.
Abnormal Bile Ducts ~ People who are born with (congenital) abnormalities of the bile ducts, such as choledochal cysts, are more at risk of developing this type of cancer.
Infection ~ In Africa and Asia, infection with a parasite known as the liver fluke is thought to cause a large number of bile duct cancers.
Bile duct cancer, like other cancers, is not infectious and cannot be passed on to other people.
Signs and Symptoms
If cancer develops in the bile ducts it may block the flow of bile from the liver to the intestine. This causes the bile to flow back into the blood and body tissues, and leads to the skin and whites of the eyes becoming yellow (known as jaundice). The urine also becomes a dark yellow colour and stools (bowel motions) are pale. The skin may become itchy. Mild discomfort in the abdomen, loss of appetite, high temperatures (fevers) and weight loss may also occur.
These symptoms can be caused by many things other than bile duct cancer, but any jaundice or any symptoms which get worse or last for a few weeks should always be checked by your doctor.
The stage of a cancer is a term used to describe its size and whether it has spread beyond its original site. Knowing the particular type and the stage of the cancer helps the doctors to decide on the most appropriate treatment.
Cancer can spread in the body, either in the blood stream or through the lymphatic system. The lymphatic system is part of the body’s defense against infection and disease. The system is made up of a network of lymph glands (also known as lymph nodes) that are linked by fine ducts containing lymph fluid. Doctors will usually look at the lymph nodes close to the biliary system in order to find the stage of this type of cancer.
Stage 1A ~ The cancer is contained within the bile duct.
Stage 1B ~ The cancer has spread through the wall of the bile duct but has not spread into nearby lymph nodes or other structures.
Stage 2A ~ The cancer has spread into the liver, pancreas or gall bladder or to the nearby blood vessels, but not the lymph nodes.
Stage 2B ~ The cancer has spread into nearby lymph nodes.
Stage 3 ~ The cancer is affecting the main blood vessels that take blood to and from the liver, or it has spread into the small or large bowel, the stomach or the abdominal wall. Lymph nodes in the abdomen may also be affected.
Stage 4 ~ The cancer has spread to distant parts of the body such as the lungs.