Causes & risk factors for gallbladder cancer

Researchers have found several risk factors that make a person more likely to develop gallbladder cancer.

Most doctors studying the subject think that chronic inflammation is the major cause of gallbladder cancer. When the gallbladder release bile slowly, the gallbladder tissue is exposed to the bile for longer than usual. This may lead to irritation and inflammation. Scientists also suspect that this longer exposure to possible cancer-causing substances in the bile could also be responsible. Certain abnormalities in the ducts that carry fluids from the gallbladder and pancreas to the small intestine can cause juices from the pancreas to flow backward into the gallbladder and bile ducts. Researchers suspect that this reflux (backward flow) of pancreatic juices may irritate the cells lining the gallbladder and bile ducts in a way that causes irritation and inflammation. This may stimulate their growth and perhaps make them more sensitive to cancer-causing substances.

Risk factors for gallbladder cancer 

• Gallstones: Gallstones are the most common risk factor for gallbladder cancer.
• Porcelain gallbladder: Porcelain gallbladder is a condition in which the wall of the gallbladder becomes covered with calcium deposits.
• Female gender: In the United States, gallbladder cancer occurs more than twice as often in women. Gallstones and gallbladder inflammation, 2 important risk factors for gallbladder cancer, are much more common among women than men.
• Obesity: Patients with gallbladder cancer are more often overweight or obese than people without this disease.
• Older age: While it can occur at younger ages, gallbladder cancer is seen mainly in older people. The average age at the time of diagnosis is 73. Almost 3 out of 4 people with gallbladder cancer are older than age 65 when it is found.
• Ethnicity: Native Americans, particularly in the southwestern United States, and Mexican Americans have a higher rate of gallbladder cancer.
• Choledochal cysts: Choledochal cysts are bile-filled sacs that are connected to the common bile duct, the tube that carries bile from the liver and gallbladder to the small intestine. The cysts can grow over time and may contain as much as 1 to 2 quarts of bile. The cells lining the sac often have areas of pre-cancerous changes, which increase a person’s risk for developing gallbladder cancer.
• Abnormalities of the bile ducts: The pancreas is another organ that releases fluids through a duct into the small intestine to aid digestion. This duct normally meets up with the common bile duct just as it enters the small intestine. Some people have abnormalities where these ducts meet that allow juice from the pancreas to reflux (flow back “upstream”) into the bile ducts. This backward flow also prevents the bile from being emptied through the bile ducts as quickly as normal. These people are at higher risk of gallbladder cancer.
• Gallbladder polyps: A gallbladder polyp is a growth that bulges outward from the surface level of the inner gallbladder wall. Some polyps are formed by cholesterol deposits in the gallbladder wall. Others may be small tumors (either cancerous or benign) or may be caused by inflammation. Polyps larger than 1 centimeter (a little less than half an inch) are more likely to be malignant, so doctors often advise removing the gallbladder in patients with gallbladder polyps that size or larger.
• Industrial and environmental chemicals: It is not clear if exposure to certain chemicals in the workplace or the environment increases the risk of gallbladder cancer. This is a difficult area to study because this cancer is not common. Some animal studies have suggested that chemical compounds called nitrosamines may increase the risk of gallbladder cancer. Other studies have found that workers in the rubber and textile industries may have more gallbladder cancers than the general public.
• Typhoid: People chronically infected with salmonella (the bacterium that causes typhoid) and those who are carriers of the disease are more likely to develop gallbladder cancer than
  those not infected. Typhoid is rare in the United States.
• Family history: A history of gallbladder cancer in the family seems to increase a person’s chances of developing this cancer, but the risk is still low because this is a rare disease.

~ by marigold on August 12, 2009.