Read about what could increase your risk of getting gallbladder cancer, including lifestyle factors and other medical conditions.
What a risk factor is
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 get that cancer.
Risks factors for gallbladder cancer
As with most cancers, gallbladder cancer is more common in older people than in younger people. In the UK, it is more common in people older than 70.
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. About 8 out of 10 people with gallbladder cancer (80%) have gallstones or an inflamed gallbladder when they are diagnosed.
One study has shown that a family history of gallstones doubles the risk of gallbladder cancer, and that people with a family history of gallstones who also have gallstones themselves have almost 60 times the normal risk of gallbladder cancer.
Gallstones are very common but gallbladder cancer is very rare. Most people with an inflamed gallbladder or gallstones do not get gallbladder cancer.
People with a first degree relative (a parent, sibling or child) with gallbladder cancer are 5 times more likely to develop gallbladder cancer than people who do not have relative with it. Because gallbladder cancer is so rare, this is still a very small risk.
One study looked at the increased cancer risk for people who carry the genetic mutation BRCA2. This mutation is known to increase the risk of breast and ovarian cancer. It also slightly increases the risk of gallbladder and bile duct cancer.
Porcelain gallbladder means that calcium deposits build up on the inside wall of your gallbladder. It is unclear whether it is a risk factor for gallbladder cancer. And gallbladder cancer is still very rare in people who have it.
If you've 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 (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.
Cigarettes and some industrial chemicals contain nitrosamines. These are chemicals that can damage DNA and increase the risk of developing cancer.
People who smoke or work in the metal or rubber industry are more likely to develop gallbladder cancer.
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. 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).
Being very overweight can increase the risk of many types of cancers, including gallbladder cancer. Obesity means you are more than 40% over the maximum desirable weight for your height. In other words, if you should weigh 10 stone at most and you weigh over 14 stone, you are obese.
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.
It has been estimated that more than one in ten cases of gallbladder cancer in men and almost a fifth of cases in women are due to being overweight.
You might have a very small increased risk of gallbladder cancer or cancer of the bile duct if you have diabetes.
Diet is a difficult risk factor to prove and much more research needs to be done in this area before we can be sure how it affects our risk of particular cancers.
Doctors are unclear how diet affects the risk of gallbladder cancer. Although there may be a link, there is not enough clear research evidence to be certain about the link between diet and gallbladder cancer.
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 or inflammation caused by abnormalities in the bile duct or pancreas.
North India has the highest rate of gallbladder cancer in the world. Other countries with significantly high rates are Israel, Chile, Ecuador and Pakistan.
In the USA the black and Hispanic population has a greater incidence of gallbladder cancer than the white population. Native Americans in southwestern USA are more likely to develop gallbladder cancer than in other parts of the USA.
Other countries with a higher rate of gallbladder cancer are Mexico, Bolivia, Korea and Japan. Lower rates are found in Singapore and Nigeria.
Salmonella infection can increase the risk of gallbladder cancer in people who have gallstones. There is strong evidence for this in Chile and North India.
A few small studies show that Helicobacter pylori bacteria might also increase the risk of gallbladder cancer.
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.