Gallbladder and bile duct cancer are relatively rare. According to the American Cancer Society, approximately 9,500 new cases of gallbladder and bile duct cancer are diagnosed each year in the United States.
The Gallbladder & Bile Ducts
The gallbladder is a small, pear-shaped organ located just underneath the liver. The gallbladder stores and concentrates bile, a fluid made by the liver that helps digest fats in the small intestine. The gallbladder contracts during digestion, releasing bile into the small intestine.
Bile ducts within the liver join together to form one main bile duct, located immediately outside the liver, which carries bile to the small intestine. This main bile duct is called the common hepatic duct. The cystic duct joins the gallbladder to the common hepatic duct, and the combined duct is called the common bile duct.
Types of Gallbladder and Bile Duct Cancer
Most primary gallbladder and bile duct cancers are adenocarcinomas, growths that begin in the mucus glands that line the insides of the gallbladder and bile ducts.
Bile duct tumors are known as cholangiocarcinoma. These tumors can occur in the main bile duct outside the liver (extrahepatic) or within the liver (intrahepatic):
Most bile duct cancers develop outside the liver. About two-thirds of all extrahepatic tumors are found in the perihilar region of the bile ducts, where the two main bile ducts meet as they leave the liver. These tumors are also called Klatskin tumors. The remaining extrahepatic bile duct tumors are called distal tumors, which are found closer to the small intestine.
About one in ten bile duct cancers develop in the small duct branches within the liver. Intrahepatic bile duct tumors are often confused with primary liver cancer (hepatocellular carcinoma), a type of cancer that begins in the liver. (For information about hepatocellular carcinoma, visit that section of our website.)
Risk Factors for Gallbladder Cancer
Gallbladder cancer typically strikes older people (aged 70 and above). It is more common among Mexican Americans, southwestern Native Americans, and people from certain South American countries, particularly Chile.
- Gallstones and Inflammation
Gallstones — hard, rocklike formations made of cholesterol and other substances in the gallbladder —are the biggest risk factor for gallbladder cancer. Up to 90 percent of people diagnosed with gallbladder cancer also have gallstones and chronic inflammation of the gallbladder. These conditions are more common in women, who are twice as likely as men to develop gallbladder cancer. People with larger gallstones (3 centimeters) are ten times more likely to develop gallbladder cancer than those with small stones (1 centimeter). However, gallstones are very common, and most people with gallstones never develop gallbladder or bile duct cancer.
Other risk factors for gallbladder cancer include:
- Porcelain Gallbladder
This is a condition in which the gallbladder becomes covered in calcium deposits, resembling porcelain ceramic. Porcelain gallbladder can occur when the gallbladder becomes inflamed.
People who are chronically, or persistently, infected with salmonella (the bacterium that causes typhoid) are six times more likely to develop gallbladder cancer than those who are not infected.
Many patients with gallbladder cancer are overweight or obese, and have a high-carbohydrate or low-fiber diet.
- Family History
Gallbladder cancer sometimes runs in families.
- Gallbladder Polyps
Gallbladder polyps are growths that protrude from the gallbladder’s mucous membrane. These polyps are usually symptomless. Some polyps are precancerous and can progress to cancer. Polyps that are 1 centimeter or larger, appear to be growing, or have a broad base should be removed to prevent cancer.
Risk Factors for Bile Duct Cancer
Like gallstones, smaller stones that form in the bile ducts can lead to chronic inflammation and increase the risk of developing bile duct cancer. Other inflammatory conditions can increase the risk of developing bile duct cancer:
- Ulcerative Colitis
Ulcerative colitis is an inflammation of the large intestine that is often associated with inflammation of the bile duct (a condition known as sclerosing cholangitis). Ulcerative colitis can progress to cancer, particularly in people exposed to other carcinogens such as cigarette smoke.
- Biliary Parasites
Although rarely seen in the United States, food- or water-borne parasites that reside in the bile ducts are common in Asia and raise the risk of developing bile duct cancer.
- Congenital Bile Duct Cysts (Choledochal Cysts)
These bile-filled sacs are connected to the common bile duct. Congenital bile duct cysts are typically diagnosed in childhood. The lining of these sacs often contains precancerous cells that increase the risk of developing cancer later in life.
- Chronic Hepatitis C
This inflammatory disease — the most common risk factor for liver cancer —also is considered a risk factor for cancer of the intrahepatic bile ducts. (For more information about hepatitis, visit the Risk Factors section of the Primary Liver Cancer overview.)
A recent study suggests that intrahepatic bile duct cancer is more common among heavy smokers.
This condition appears to be an increasingly important risk factor for intrahepatic bile duct cancer.
Gallbladder and bile duct cancer cause few symptoms until they reach an advanced stage and have spread to other organs and tissues.
Jaundice (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) and itchy skin (which can occur when a tumor blocks the bile duct) often are the first signs of bile duct cancer.
Other symptoms may include:
- general feeling of poor health or weakness
- loss of appetite
- weight loss
- swelling of the legs
1 Welzel TM, Graubard BI, El-Serag HB, Shaib YH, Hsing AW, Davila JA, McGlynn KA. Risk factors for intrahepatic and extrahepatic cholangiocarcinoma in the United States: a population-based case-control study. Clin Gastroenterol Hepatol. 2007 Oct;5(10):1221-8. Epub 2007 Aug 6. [PubMed Abstract]