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Cancer of the gallbladder is cancer of the pear-shaped organ that lies on the undersurface of the liver.
Bile from the liver is funneled into the gallbladder by way of the cystic duct. Between meals, the gallbladder stores a large amount of bile. To do this, it must absorb much of the water and electrolytes from the bile. In fact, the inner surface of the gallbladder is the most absorptive surface in the body. After a meal, the gallbladder's muscular walls contract to deliver the bile back through the cystic duct and eventually into the small intestine, where the bile can help digest food.
About 5,000 people are diagnosed with gallbladder cancer each year in the United States, making it the fifth most common gastrointestinal cancer. It is more common in females than males and most patients are elderly. Southwest American Indians have a particularly high incidence—six times that of the general population.
Causes and symptoms
Gallstones are the most significant risk factor for the development of gallbladder cancer. Roughly 75 to 90 percent of patients with gallbladder cancer also have gallstones. Larger gallstones are associated with a higher chance of developing gallbladder cancer. Chronic inflammation of the gallbladder from infection also increases the risk for gallbladder cancer.
Unfortunately, sometimes cancer of the gallbladder does not produce symptoms until late in the disease. When symptoms are evident, the most common is pain in the upper right portion of the abdomen, underneath the right ribcage. Patients with gallbladder cancer may also report symptoms such as nausea, vomiting, weakness, jaundice, skin itching, fever, chills, poor appetite, and weight loss.
Gallbladder cancer is often misdiagnosed because it mimics other more common conditions, such as gallstones, cholecystitis, and pancreatitis. But the imaging tests that are utilized to evaluate these other conditions can also detect gallbladder cancer. For example, ultrasound is a quick, noninvasive imaging test that reliably diagnoses gallstones and cholecystitis. It can also detect the presence of gallbladder cancer as well as show how far the cancer has spread. If cancer is suspected, a computed tomography scan is useful in confirming the presence of an abnormal mass and further demonstrating the size and extent of the tumor. Cholangiography, usually performed to evaluate a patient with jaundice, can also detect gallbladder cancer.
There are no specific laboratory tests for gallbladder cancer. Tumors can obstruct the normal flow of bile from the liver to the small intestine. Bilirubin, a component of bile, builds up within the liver and is absorbed into the bloodstream in excess amounts. This can be detected in a blood test, but it can also manifest clinically as jaundice. Elevated bilirubin levels and clinical jaundice can also occur with other conditions, such as gallstones.
On occasion, gallbladder cancer is diagnosed incidentally. About one percent of all patients who have their gallbladder removed for symptomatic gallstones are found to have gallbladder cancer. The cancer is found either by the surgeon or by the pathologist who inspects the gallbladder with a microscope.
Staging of gallbladder cancer is determined by the how far the cancer has spread. The effectiveness of treatment declines as the stage progresses. Stage I cancer is confined to the wall of the gallbladder. Approximately 25% of cancers are at this stage at the time of diagnosis. Stage II cancer has penetrated the full thickness of the wall, but has not spread to nearby lymph nodes or invaded adjacent organs. Stage III cancer has spread to nearby lymph nodes or has invaded the liver, stomach, colon, small intestine, or large intestine. Stage IV disease has invaded very deeply into two or more adjacent organs or has spread to distant lymph nodes or organs by way of metastasis.
Early Stage I cancers involving only the innermost layer of the gallbladder wall can be cured by simple removal of the gallbladder. Cancers at this stage are sometimes found incidentally when the gallbladder is removed in the treatment of gallstones or cholecystitis. The majority of patients have good survival rates. Late Stage I cancers, which involve the outer muscular layers of the gallbladder wall, are generally treated in the same way as Stage II or III cancers. Removal of the gallbladder is not sufficient for these stages. The surgeon also removes nearby lymph nodes as well as a portion of the adjacent liver (radical surgery). Survival rates for these patients are considerably worse than for those with early Stage I disease. Patients with early Stage IV disease may benefit from radical surgery, but the issue is controversial. Late Stage IV cancer has spread too extensively to allow complete excision. Surgery is not an option for these patients.
When long-term survival is not likely, the focus of therapy shifts to improving quality of life. Jaundice and blockage of the stomach are two problems faced by patients with advanced cancer of the gallbladder. These can be treated with surgery, or alternatively, by special interventional techniques employed by the gastroenterologist or radiologist. A stent can be placed across the bile ducts in order to re-establish the flow of bile and relieve jaundice. A small feeding tube can be placed in the small intestine to allow feeding when the stomach is blocked. Pain may be treated with conventional pain medicines or a celiac ganglion nerve block.
Current chemotherapy or radiation therapy cannot cure gallbladder cancer, but they may offer some benefit in certain patients. For cancer that is too advanced for surgical cure, treatment with chemotherapeutic agents such as 5-fluorouracil may lengthen survival for a few months. The limited benefit of chemotherapy must be weighed carefully against its side effects. Radiation therapy is sometimes used after attempted surgical resection of the cancer to extend survival for a few months or relieve jaundice.
Cholangiography — Radiographic examination of the bile ducts after injection with a special dye
Cholecystitis — Inflammation of the gallbladder, usually due to infection
Computed tomography — A radiology test by which images of cross-sectional planes of the body are obtained
Jaundice — Yellowish staining of the skin and eyes due to excess bilirubin in the bloodstream
Metastasis — The spread of tumor cells from one part of the body to another through blood vessels or lymphatic vessels
Pancreatitis — Inflammation of the pancreas
Stent — Slender hollow catheter or rod placed within a vessel or duct to provide support or maintain patency
Ultrasound — A radiology test utilizing high frequency sound waves
Abeloff, Martin D. "Gallbladder Carcinoma." In Clinical Oncology. 2nd ed. New York: Churchill Livingstone, 2000, pp.1730-1737.
Ahrendt, Steven A., and Henry A. Pitt. "Biliary Tract." In Sabiston Textbook of Surgery, edited by Courtney Townsend, Jr., 16th ed. Philadelphia: W.B. Saunders Company, 2001, pp. 1076-1111.
National Cancer Institute Cancer Trials web site. http://cancertrials.nci.nih.gov/system. http:// www.cancertrials.com.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
gallbladder cancerThe fifth most common GI cancer in the US, and most common hepatobiliary cancer. It arises in a background of chronic inflammation, most (>75%) are linked to cholesterol gallstones (which increase the risk of gallbladder cancer 4- to 5-fold). Less common causes of chronic inflammation include primary sclerosing cholangitis, ulcerative colitis, liver flukes, chronic Salmonella typhi and S paratyphi colonization, and Helicobacter infection.
Asymptomatic if early; if late, jaundice, abdominal pain, fever, nausea, vomiting, bloating, palpable mass, periumbilical lymphadenopathy.
ERCP with biopsy.
Mass on ultrasound, CT, MRI, percutaneous transhepatic cholangiography.
CEA, CA19-9, liver enzymes might be elevated.
Excision is possible; if not resectable (which is common), palliative procedures may be used including biliary bypass, endoscopic stent placement, and percutaneous transhepatic biliary drainage.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.