Gallbladder cancer is a rare cancer. We don't know what causes most cases but there are some known risk factors.
Anything that can increase your risk of getting a disease is called a risk factor.
Different cancers have different risk factors. Having one or more of these risk factors doesn't mean you will definitely get that cancer.
Risks factors for gallbladder cancer
Age and sex
Your risk of getting gallbladder cancer increases as you get older. Most people who develop it are aged between 85 and 89. Remember, the risk is still small because this is a rare cancer.
Gallbladder cancer is more common in women than men. 71 out of 100 people diagnosed with gallbladder cancer (71%) are women.
Gallstones and inflammation
Gallstones and inflammation of the gallbladder (cholecystitis) are the most common risk factors for gallbladder cancer.
Gallstones are hard lumps, like little rocks, that form in the gallbladder. They are mostly cholesterol, mixed with other substances found in bile. Bile is a liquid made by the liver to digest fats and is stored in the gallbladder.
The risk of gallbladder cancer is around 5 times higher in people with a history of gallbladder conditions (mainly gallstones), compared to those who don’t.
Gallstones are very common but gallbladder cancer is very rare. Most people with an inflamed gallbladder or gallstones do not get gallbladder cancer.
Family history of gallbladder cancer
People with a family history of gallbladder cancer are 5 times more likely to develop gallbladder cancer than those with no relatives with it. Because gallbladder cancer is so rare, this increase in risk is still very small.
The risk of developing gallbladder cancer is very different for people living in different parts of the world, and for different racial groups. This is likely to be due to factors affecting these populations such as infection, gallstones, inflammation or diet.
Areas of the world where gallbladder cancer is significantly high are:
- Latin America
Low rates of gallbladder cancer are found in:
- western countries such as UK, USA, Australia, Canada and New Zealand
- Mediterranean and western European countries
Porcelain gallbladder is a result of chronic inflammation and means that calcium deposits build up on the inside wall of your gallbladder. People with this condition have an increased risk of gallbladder cancer, but it’s rare.
If you have had an inflamed gallbladder many times you may get porcelain gallbladder. If you have this condition, your doctor may suggest that you have surgery to take your gallbladder out.
Primary sclerosing cholangitis
Primary sclerosing cholangitis (PSC) is a type of inflammation of the bile ducts. It’s a rare condition and we don't know what causes it. People who have this condition have a slightly increased risk of developing gallbladder cancer.
People who smoke increase their risk of gallbladder cancer.
Being overweight or obese can increase the risk of many types of cancers, including gallbladder cancer.
Being overweight causes changes in hormones in the body, particularly for women. It could be this change in the body’s hormone balance that increases the risk of gallbladder cancer.
Being overweight or obese also means you are more likely to develop gallstones which increases your risk of gallbladder cancer.
Pancreas and bile duct abnormalities
Some abnormalities of the pancreas and bile duct increase your risk of getting gallbladder cancer. These include:
- outgrowths along the bile duct (choledochal cysts - pronounced kol-eh-doke-al sist)
- an abnormality of the join between the bile duct and the pancreas
These are both conditions you are born with. They are very rare. Most people born with these conditions will develop symptoms in early childhood. But some do not develop any until adulthood. Most people with choledochal cysts have an abnormal bile duct junction as well.
Choledochal cysts are there from birth in affected people. They are sacs that connect to the bile duct and fill up with bile. They grow slowly and can end up holding up to 2 litres of bile. The cells that line the sacs can be abnormal and occasionally show precancerous changes. Having this condition increases your risk of getting gallbladder cancer in the future.
Doctors call an abnormality of the area where the bile duct joins with the pancreas an anomalous pancreatobiliary duct junction. If you have this, it means that pancreatic juices and enzymes can go back up into the common bile duct. These digestive juices irritate and inflame the bile duct wall. Over time, this can weaken it.
Scientists are still not sure whether the increased risk of gallbladder cancer is due to irritation from the pancreatic digestive juices or from bile not being able to flow easily through the bile ducts.
These small growths are not cancer and many adults have them. They develop on the surface lining of the gallbladder. But some might develop into cancer over a long period of time.
The larger the polyp, the greater that risk is that it will become cancerous. You might have an operation to remove your gallbladder if you have a polyp that is larger than 1 centimetre (10mm).
You might have an increased risk of gallbladder cancer or cancer of the bile duct if you have diabetes.
Drinking alcohol can increase your risk of gallbladder cancer. Heavy drinkers are more at risk of developing gallbladder than moderate drinkers. And the less you drink, the lower your risk of gallbladder cancer.
Ionising radiation is a type of radiation used by some medical scans, such as x-rays and CT scans. These scans are important to help diagnose many illnesses, including cancer.
Ionising radiation increases your risk of gallbladder cancer. Remember, the risk is still very small because this is a rare cancer.
The risks of radiation from medical scans are very low. Your doctors and dentist will keep your exposure to radiation as low as possible. They will only do x-rays and CT scans when they are necessary.
Other possible causes
Stories about potential causes of cancer are often in the media. It isn’t always clear which ideas are supported by good evidence.
You might hear about possible causes we haven’t included here. This is because there is no evidence about them or because the evidence isn’t clear.