Gallbladder cancer develops in the tissues of the gallbladder, the organ in the body that collects bile from the liver used to digest fat. Gallstones occur when bile inside the gallbladder hardens. While important to digesting fat, the gallbladder can be removed without causing problems. The causes of gallbladder cancer are unclear. According to the National Cancer Institute, gallbladder cancer is uncommon with only 9,760 cases reported in the United States in 2009.
Irritation and Inflammation
Irritation and inflammation may stimulate cell growth and increase sensitivity to cancer-causing substances. If gallstones develop, the gallbladder releases bile more slowly, leading to irritation. Chronic inflammation can develop over time. According to the American Cancer Society, a longer exposure to potential cancer-causing substances in the bile could cause gallbladder cancer.
Cell Changes
Cancer develops when cells change, or mutate, inappropriately. Changes in the cells of the tissues lining the inside of the organ cause gallbladder cancer. Cell mutation is caused by changes in DNA, the portion of the cell that stores inherited genetic information. Some cancers are caused by inherited DNA, but changes in DNA in gallbladder cancer are more likely due to environmental exposure, according to the American Cancer Society. Excessive sunlight, smoking, exposure to cancer-causing agents and some chemical exposures increase the risk of cell mutation that could lead to cancer. While not directly inherited, a family history of gallstones increases the risk of gallbladder cancer, according to CancerHelp UK.
Exposure to Asbestos
The Environmental Protection Agency has identified asbestos as a cancer-causing agent. According to the National Cancer Institute, exposure to asbestos may be a cause of gallbladder cancer.
Choledocal Cysts and Abnormal Bile Ducts
Cysts filled with bile and attached to the common bile duct can have pre-cancerous cells in their lining. These are called choledocal cysts and can increase the risk for developing gallbladder cancer, according to the American Cancer Society. Ducts, the tubes that carry fluids to and from the gallbladder, may also be abnormal, allowing pancreatic juice to flow backward into the organ causing irritation. Abnormal ducts may be present at birth.
Obesity
The National Cancer Institute reports that obesity may contribute to a variety of cancers, including gallbladder cancer. Controlling weight may decrease the risk of developing gallbladder cancer.
Gallbladder Polyps
Polyps are abnormal growths that can occur in the tissues of the gallbladder. Over time, these polyps may become cancerous. The gallbladder may be removed if polyps are found.
