The gallbladder is a small pear shaped sac that lies under the liver. Its main function is to store and concentrate bile. Bile is a yellowish green liquid produced by the liver that helps digest fats. Its main function is to break down fats in food.
Bile is passed from the liver through a series of channels, called bile ducts, into the gallbladder, where it is stored. The gallbladder concentrates the bile to increase its effectiveness in digesting fats.
The gallbladder releases bile into the digestive system when it is needed. The gallbladder along with bile ducts is called the biliary system.
Although an important organ, the gallbladder can be safely removed when diseased so that the bile flows directly from the liver into the digestive system. Thus, it is a useful but not essential, organ.
Gallbladder cancer is the cancer of this organ that affects around 670 people each year and affects women more commonly than men. The cancer affects people over 50 more commonly and is rare among younger adults and children.
It is relatively uncommon in Europe but is more common in Chile, Bolivia and Israel. In the United States an estimated 9,810 new cases are diagnosed with 4,480 in men and 5,330 in women.
Most of the gall bladder cancers are of the type adenocarcinoma. These begin in the inner walls and linings of the organ.
The early symptoms of this cancer are often not detectable. As the disease progresses the symptoms manifest themselves and include abdominal pain, nausea, vomiting and jaundice. The urine also becomes a dark yellow or brown colour and stools are pale and chalky. The skin may become itchy. These are symptoms of liver disease as well and need to be evaluated carefully.
Patients with a history of gallstones or in people who have inflammation of the gall bladder (cholecystitis) are at a higher risk of getting gall bladder cancer. However, not all individuals with gallstones will get cancer.
People that are at a greater risk of gallbladder cancer include:
people with non-cancerous benign tumors of the gall bladder called polyps,
those with congenital abnormalities of the bile ducts,
those with a family member (parent, brother or sister) affected with this cancer,
those who are obese or overweight,
those who have a condition called porcelain gall bladder.
Gallbladder cancer is usually detected when operating for gall stones. In some patients it may detected while evaluating for liver disease. Tests for diagnosis include liver function tests and blood tests and imaging studies like ultrasonography, MRI and CT scans.
Gallbladder cancer is treated using a combination of surgical removal of the organ followed by chemotherapy with anticancer drugs and radiation therapy. If detected in fairly early stages, the cancer may be well controlled.
Those with advanced disease however have a poor outlook from treatment and these patients need palliative therapy to ease the symptoms. Palliative care also includes support in very advanced cases and end-of-life care.
Gallbladder cancer is a rare cancer in the European countries. Around 640 to 670 new cases are diagnosed each year.
Gallbladder cancer is more common in women than in men. About 7 out of every 10 cases diagnosed are in women. In addition, they are commonly seen in individuals over the age of 70 and are rare in people below 50.
Most of the gallbladder cancers are adenocarcinoma where the cancer begins in the inner lining of the gall bladder. The exact cause of gallbladder cancer is unknown but there are certain risk factors that raise the risk of gallbladder cancer.
Different cancers have different risk factors. Those with the risk factors do not mean that they will definitely get the cancer.
Risk factors that predispose to gallbladder cancer include old age, sex of the patient, cholecystitis and so forth.
Most of the gallbladder cancers affect elderly people and the cancer is rare under the age of 70 in the UK.
Gallbladder disease as such is more common in women. Similarly gallbladder cancer affects women more commonly than men.
Gallstones and inflammation of the gallbladder is also known as cholecystitis. This is by far the most common risk factor that predisposes to gallbladder cancer.
Gallstones are hard stones that are formed within the gallbladder due to deposition of cholesterol and minerals from bile.
About 8 out of 10 people with gallbladder cancer (80%) have gallstones or an inflamed gallbladder at diagnosis. However, most people with an inflamed gallbladder or gallstones do not get gallbladder cancer.
Those with someone in the family (a first degree relative like a parent or a sibling) with gallstones have a double the chance of gallbladder cancer.
In addition, those with a family history of gallstones who also have gallstones themselves have almost 60 times the normal risk of gallbladder cancer.
Those with a first degree relative with gallbladder cancer are five times more likely to develop gallbladder cancer than people who do not have a relative with it. The risk, however, still remains very small as the cancer is rare.
The genetic mutation BRCA2 that leads to increased risk of breast and ovarian cancer also slightly increases the risk of gallbladder and bile duct cancer.
Some races and ethnicities are more at risk of gall bladder cancer than others. The basis could be genetics. For example, north India has the highest rate of gallbladder cancer in the world. Other countries with significantly high rates are Israel, Chile, Ecuador, Bolivia, Mexico, Korea, Japan and Pakistan.
Among Americans black and Hispanic population as well as Native Americans in south-western USA have a greater incidence of gallbladder cancer than the white population. Lower rates are found in Singapore and Nigeria.
Cigarettes and some industrial chemicals containing nitrosamines can damage the DNA and lead to genetic mutations and raise the risk of gallbladder and other cancers. Workers in the metal or rubber industry are more likely to develop gallbladder cancer.
This is a condition where calcium deposits build up on the inside wall of the gallbladder hardening the walls. This is usually seen in individuals who have repeated cholecystitis or inflammation of the gallbladder.
This is a form of inflammation of the bile ducts. This also raises the risk of gallbladder cancer.
Defects of the pancreas and bile ducts raise the gallbladder cancer risk. Abnormalities in the connection between the bile duct and the pancreas, outgrowths in the bile duct (choledochal cysts) may also be risk factors for gall bladder cancer. These conditions may affect a baby since birth but symptoms may appear much later.
These are non-cancerous growths within the gallbladder. They develop on the surface lining of the gallbladder. Over a long time these may develop into cancers. Polyps over 1 centimetre (10mm) usually need surgical removal of the gallbladder to prevent cancer.
Being obese or overweight raises the risk of gallstones and cholecystitis. This is mainly because they change the hormonal balances of the body particularly for women. Studies show that more than one in ten cases of gallbladder cancer in men and almost a third of cases in women are due to being overweight.
Diet high in carbohydrates and low in fibre may increase the risk of gallbladder cancer. Diet rich in fresh fruit and vegetables seems to reduce the risk of many cancers, including gallbladder cancer. Inclusion of vitamins A, C and E and antioxidant chemicals in diet is also important for cancer prevention.
Diabetes may also raise the risk of gallbladder cancer.
Typhoid causing Salmonella infection can increase the risk of gallbladder cancer in people who have gallstones. This is seen commonly in Chile and North India. Helicobacter pylori - bacteria responsible for peptic ulcers, may also raise risk of gallbladder cancers.
Women who have increased exposure to the hormone oestrogen may have an increased risk of gallbladder cancer. With longer use of Hormone replacement therapy the risk of gallbladder cancer seems to rise.
Gallbladder cancers are notoriously difficult to detect early. These cancers usually do not cause symptoms in its early stages. By the time symptoms manifest the cancer may have advanced to later stages.
At diagnosis the cancer has often spread outside the gallbladder itself to areas nearby. The affected gallbladder is difficult to feel from above the abdomen as it lies deep within underneath the liver. In most cases a gallbladder cancer is detected by chance during a surgery for gallstones.
Most of the symptoms appear in later stages and other illnesses like liver disease may also cause similar symptoms.
Symptoms of gallbladder cancer include abdominal pain, nausea and vomiting and so forth.
The pain is typically aching and occurs on the right side. These may be a dragging feeling. There is a sharper pain or biliary colic that may be sudden and severe in onset in case the cancer or gallstones block the bile duct. This condition needs immediate emergency treatment.
In later stages of gall bladder cancer as well as in early stages there is intense nausea, vomiting and lack of appetite. There may be bloating, abdominal discomfort particularly after a heavy or fatty meal.
This means the liver is unable to function or there is a blockage in the biliary system and the bile seeps into the blood. The bile pigments are yellowish green and they get deposited at various parts of the body.
For example, when these pigments are deposited in the eyes they lead to yellowing of the whites of the eyes. They may be deposited elsewhere leading to yellowing of the skin, yellowing of the nail beds etc. The bile chemicals under the skin also lead to severe itching.
The urine may be dark or deep yellow in color due to excess bile pigments and the stools may be white, pale and chalky due to lack of bile pigments secreted in the digestive tract. Nearly half the people diagnosed with gallbladder cancer have jaundice. This is often a sign that the cancer is in its later stages.
However, having jaundice does not always mean that the patient has cancer. A viral infection of the liver, liver ailments, alcoholic liver disease etc. also causes jaundice. A viral hepatitis is the commonest cause of jaundice.
If the biliary system of bile ducts is blocked with cancer the gallbladder will fill up with bile and get swollen and enlarged. This enlarged gall bladder may be felt during a physical examination or visualized during an ultrasound scan.
Other symptoms include loss of appetite, unexplained weight loss and a swollen abdomen.