Cancer-Related Resources Informative and helpful resources on other Web sites for cancer patients and their caregivers 
|
|
|
The incidence of both gallbladder and bile duct cancer is rare and accounts for a very small percentage of all cancers. According to the American Cancer Society, approximately 8,750 new cases of gallbladder and bile duct cancer will be diagnosed in 2006.
Functions of the Gallbladder & Bile Duct
The gallbladder is a small, pear-shaped organ that stores and concentrates bile. Located under the right lobe of the liver, the gallbladder is connected to the liver by the hepatic duct. The gallbladder is approximately three to four inches long and about one inch wide.
The gallbladder stores bile (a fluid made by the liver that helps digest fats in the small intestine) and concentrates it. Bile may be released from the liver directly into the small intestine or stored in the gallbladder and released later. When food is being digested, the gallbladder contracts, and releases bile into the small intestines through the common bile duct.
The primary function of the bile duct is to transport bile to the small intestine where it aids in the digestion of food. The bile duct is a thin tube -- about four to five inches long -- and runs from the liver to the small intestine. The bile duct begins as many small channels that gather bile from the liver, join to form one tube -- called the common hepatic duct. Joining the gallbladder to the bile duct is the cystic duct, and the combined duct is called the common bile duct. The common bile duct empties into the small intestine.
How Gallbladder or Bile Duct Cancer Develops
Most primary gallbladder and bile duct cancers originate in the mucosa -- the innermost layer of the organs -- and spread through the outer layers as the cancer grows. Gallbladder cancer is difficult to detect and diagnose because it causes few symptoms until it has reached an advanced stage. It is most often discovered incidentally through surgical removal of the gallbladder for other reasons. Since only one-fourth of gallbladder cancer is detected in early stages, the rate of cure for patients diagnosed with gallbladder cancer is, on average, 15 percent.
Bile duct cancer can develop within the liver (intrahepatic cholangiocarcinoma) or outside the liver (extrahepatic cholangiocarcinoma). Only five to ten percent of bile duct cancers are "intrahepatic," meaning those cancers that develop in those small duct channels inside the liver. But according to the American Cancer Society, intrahepatic bile duct cancers are on the rise. This type of bile duct cancer creates minimal symptoms and is typically discovered as a liver mass during a diagnostic scan.
Outside the liver, "extrahepatic" bile duct cancers usually develop in one of two places -- in either the perihilar or the distal regions of the bile duct. About two-thirds of bile duct cancers are "perihilar," meaning that they develop at the hepatic duct where the small ducts have joined and are leaving the liver. About one-fourth of bile duct cancers are found in the common bile duct near the intestine and pancreas -- these are called "distal" bile duct cancers.
Extrahepatic bile duct cancers often go undetected until the person becomes jaundiced, a condition in which the skin and the whites of the eyes become yellow, urine darkens, and the color of stool becomes lighter than normal. Becoming jaundiced is an indicator that the liver is not working properly or that the bile duct is blocked. Some tumors can be diagnosed before the onset on jaundice if blood work shows abnormal liver function. A proper work-up is done to determine next steps.
Some tumors can be diagnosed early, before jaundice, if blood work shows abnormal liver function. In these cases, a full work-up is done to determine the next steps in treatment.
Gallstones or conditions such as porcelain gallbladder are risk factors for gallbladder cancer. Patients with certain medical conditions -- such as ulcerative colitis or primary sclerosing cholangitis -- have a higher incidence of bile duct cancer, but most of these cancers develop in otherwise healthy patients with no known risk factors. For more information, visit the Risk Factors and Symptoms sections of this Web site.
