A risk factor is anything that affects a person's chance of getting a disease. Different cancers have different risk factors. Some risk factors, such as smoking, can be controlled. Others, like a person's age or family history, can't be changed. But risk factors don't tell us everything. Having a risk factor, or even many, does not mean that a person will get cancer. And many people who get the disease don't have any known risk factors.

Risk factors

There are some risk factors that make a person more likely to develop liver cancer.

Gender: Men are more likely to get liver cancer than are women. This could be because of the behaviors listed below, such as smoking and alcohol abuse.

Race/ethnicity: In the U.nited States, Asian Americans and Pacific Islanders have the highest rates of liver cancer, followed by American Indians/Alaska Natives and Hispanics/Latinos, African Americans, and whites.

Certain types of liver disease: The most common risk factor for liver cancer is infection with hepatitis B virus (HBV) or hepatitis C virus (HCV). These infections lead to cirrhosis and are common in many parts of the world. In this country, hepatitis C is the most common cause of liver cancer, while in other countries, hepatitis B is more common. These viruses are spread from person to person through sharing dirty needles (such as in drug use), unprotected sex, or childbirth. They can also be passed on through blood transfusions. This is rare in the United States because blood products are now tested for these viruses. People with hepatitis A infection do not have an increased risk of liver cancer.

There are also some inherited liver diseases that increase the risk of liver cancer.

Cirrhosis: Cirrhosis is a disease in which liver cells are damaged and replaced with scar tissue. This can often lead to cancer. In this country, the major causes of liver cirrhosis are alcohol abuse and hepatitis B and C. Another cause is a disease (called hemachromatosis) that results in too much iron in the liver. Some other rare diseases can cause cirrhosis, too.

Diabetes: Diabetes can increase the risk of liver cancer. This is more common in diabetics who have other risk factors such as heavy drinking and/or hepatitis.

Obesity: Being very overweight might increase the risk of getting liver cancer.

Aflatoxins: These cancer-causing substances are made by a fungus that can get into peanuts, wheat, soybeans, groundnuts, corn, and rice. Long-term exposure to aflatoxins can increase the risk of liver cancer. In the United States and Europe, these foods are tested for aflatoxins.

Vinyl chloride and thorium dioxide (Thorotrast): These chemicals are risk factors for some types of liver cancer. They have become much less important since Thorotrast is no longer used and exposure to vinyl chloride is strictly controlled.

Anabolic steroids: These male hormones are used by some athletes to increase their strength. Long-term use of these can slightly increase the risk of liver cancer.

Arsenic: In some parts of the world, drinking water is contaminated with arsenic, which increases the risk of liver cancer. This is a concern in some areas of the United States.

Less certain risk factors for liver cancer

Birth control pills: Birth control pills may slightly increase the risk of liver cancer. Most of the studies linking birth control pills and cancer involve types of pills that are no longer used. Birth control pills are now made in a different way, and it is not known if the newer ones increase liver cancer risk.

Tobacco: Some studies have found a link between smoking and liver cancer, but the extent of this is not known.

Last Medical Review: 01/09/2009
Last Revised: 05/06/2009