Gallbladder cancer refers to cancers that start in the gallbladder, a pear-shaped organ under the right lobe of the liver. The gallbladder generates and concentrates bile, which aids in the digestion of fats.
Cancer of the gallbladder is fairly rare in the United States. There are about 6,000 new cases of gallbladder cancers in the U.S. each year, more than 60 percent of diagnosed cases are in women. About one-third of all cases result in death, but the death rate has been dropping slowly over the past twenty years. About 90 percent of gallbladder cancers are adenocarcinomas. The remainder are papillary adenocarcinomas (which are far less aggressive), and other rare forms.
Most doctors believe that gallbladder cancer is caused by chronic inflammation. The most common risk factor is having gallstones: the hard, rock-like formations of cholesterol in the gallbladder that cause chronic inflammation. About 75 percent of gallbladder cancer patients have gallstones when diagnosed, although many more people experience gallstones without contracting cancer. A condition called porcelain gallbladder – where the inside of the gallbladder becomes covered with calcium deposits – has also been linked to gallbladder cancer.
Age is an important risk factor for gallbladder cancer. The average age of diagnosis is 73, with 75 percent of all cases occurring in people over the age of 65. In the U.S., gallbladder cancer is most common in Mexican-Americans and Native Americans; it is least common in African-Americans. Worldwide, gallbladder cancer is much more common in Asia, Eastern Europe, and South America than in the U.S. Obesity can increase the risk, as can certain cysts and abnormalities of the bile ducts.
Symptoms of gallbladder cancer include abdominal pain in the upper right part of the abdomen, nausea, vomiting, jaundice, enlargement of the gallbladder, and black, tarry stools. These are also symptoms of gallstones and some other conditions; most people with these symptoms do not have gallbladder cancer. However, if these symptoms are present, the patient should consult a physician.
Gallbladder cancers are most likely to be cured if diagnosed and treated early, before the cancer can metastasize (spread to other organs). The five-year survival rate of gallbladder cancer patients diagnosed at or before stage 1, is over 50 percent.
Most of the risk factors for gallbladder cancer are beyond anyone's control, so it is difficult to prevent onset of the disease. Doctors recommend leading a healthy lifestyle, consuming most calories from plant sources, maintaining a healthy weight, and limiting intake of fat.
When the cancer has not spread beyond the gallbladder, the most common treatment option is surgery. Many people live normal lives without a gallbladder. Gallbladder cancer is also treated with radiation or chemoradiation. Chemotherapy is used to reduce tumors or slow their growth, but does not cure the cancer by itself.