Risk factors for gallbladder cancer
A risk factor is something that increases the risk of developing cancer. It could be a behaviour, substance or condition. Most cancers are the result of many risk factors. But sometimes, gallbladder cancer develops in people who don’t have any of the risk factors below.
Having gallstones is the most important risk factor for gallbladder cancer. More women than men develop gallbladder cancer. Women have higher rates of gallstones and gallbladder inflammation, and this may contribute to their higher risk.
Gallbladder cancer increases with age. Most people diagnosed with gallbladder cancer are over age 65.
Gallbladder cancer rates are higher in certain countries and ethnic groups. Higher than average rates of gallbladder cancer occur in Israel, India, Latin America, eastern Asia and Europe. In North America, the number of people who get gallbladder cancer is low, except for First Nations people of Canada and Native and Hispanic Americans.
Risk factors are generally listed in order from most to least important. But in most cases, it is impossible to rank them with absolute certainty.
|Known risk factors||Possible risk factors|
Known risk factors
There is convincing evidence that the following factors increase your risk for gallbladder cancer.
The presence of gallstones in the gallbladder is called cholelithiasis. Gallstones are hard deposits of cholesterol and other substances. They can cause inflammation of the gallbladder. Having gallstones is a common condition, especially in women. Having a history of gallstones is the most common risk factor for developing gallbladder cancer. But only a very small number of people with gallstones will develop gallbladder cancer.
Inflammation of the gallbladder is called cholecystitis. Chronic, or long-standing, inflammation of the gallbladder can increase your risk of developing gallbladder cancer.
Many risk factors for gallbladder cancer, including gallstones and bacterial infection, can cause inflammation. This leads to a higher risk of gallbladder cancer. Primary sclerosing cholangitis, a disease of the bile ducts, can also cause chronic inflammation and a higher risk of gallbladder cancer.
Porcelain gallbladder is an uncommon condition. Calcium builds up on the walls of the gallbladder, causing it to harden (calcify). It may be caused by chronic inflammation of the gallbladder, usually because of gallstones.
Choledochal cysts (congenital cystic disease of the biliary tree) are rare. They develop from an abnormal increase in the size of the bile ducts at birth (congenital). Choledochal cysts can cause an abnormal flow of bile and inflammation in the bile ducts and gallbladder.
The pancreaticobiliary duct junction is the point where the pancreatic duct and the bile ducts join outside the first part of the small intestine (duodenum). An abnormality at this junction is called an anomalous junction of the pancreaticobiliary duct. It is rare and present at birth. It causes the pancreatic digestive juices to flow back into the bile ducts rather than into the small intestine. This can lead to chronic irritation of the gallbladder.
Chronic bacterial infections may cause chronic inflammation or irritation of the gallbladder and increase the risk of gallbladder cancer. These infections include:
- Salmonella typhi (S. typhi) causes typhoid fever. Sometimes the bacteria stays in the body but doesn’t cause any symptoms. People with this carrier state often get gallstones, which may contribute to a higher risk of gallbladder cancer.
- Helicobacter bilis (H. bilis) and Helicobacter pylori (H. pylori) have been linked to a higher risk of gallbladder cancer. Helicobacter may result in gallstone formation and cholecystitis.
Research shows that being overweight or obese is a risk factor for gallbladder cancer. Obesity is linked with gallstones, the most common risk factor for gallbladder cancer.
A gallbladder polyp is a growth on the inside lining of the gallbladder. Most polyps are non-cancerous. Polyps larger than 1 cm are more likely to become cancerous. Cancerous gallbladder polyps are found more often in older people.
Thorotrast (thorium dioxide) is a contrast medium that was used for imaging tests in the past. Studies have found that people who were injected with Thorotrast have a higher risk of gallbladder cancer.
The following factors have been linked with gallbladder cancer, but there is not enough evidence to show they are known risk factors. More research is needed to clarify the role of these factors for gallbladder cancer.
If you have a family history of gallbladder cancer, you may have a higher risk of developing the disease.
A history of diabetes is linked with a higher risk of some gastrointestinal cancers, including a slightly higher risk of gallbladder cancer.
People who have had a partial gastrectomy (partial removal of the stomach) have a higher risk of biliary tract cancers, including gallbladder cancer. This may be linked to the higher risk of gallstones after a partial gastrectomy.
Number of pregnancies
Some research links a greater number of pregnancies with a higher risk of gallbladder cancer. This may be because of the higher risk of gallstones during pregnancy.
Unknown risk factors
It isn’t known whether or not the following factors are linked with gallbladder cancer. It may be that researchers can’t show a definite link or that studies have had different results. More research is needed to see if the following are risk factors for gallbladder cancer:
- being exposed at work to toxic chemicals in some industries, such as automotive, rubber, textile and metal
- some drugs, such as the birth control pill (oral contraceptives) and methyldopa
- drinking water polluted with pesticides or heavy metals
- coffee, tobacco and alcohol
Questions to ask your healthcare team
To make the decisions that are right for you, ask your healthcare team questions about risks.
A small growth on a mucous membrane, such as the lining of the colon, bladder, uterus (womb), vocal cords or nasal passage.
Most types of polyps are non-cancerous, but some have the potential to become cancer.
A substance used in some diagnostic procedures to help parts of the body show up better on x-rays or other imaging tests.
In most cases, contrast medium is injected into or around the structure to be examined.
Also called contrast dye or contrast agent.
I’m extremely grateful to the Canadian Cancer Society for funding my research with an Innovation Grant.
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