ON THIS PAGE: You will find out more about the factors that increase the chance of developing this type of cancer and ways to lower your risk. To see other pages, use the menu on the side of your screen.
A risk factor is anything that increases a person’s chance of developing cancer. Although risk factors often influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do. However, knowing your risk factors and talking about them with your doctor may help you make more informed lifestyle and health care choices.
The following factors can raise a person’s risk of developing HCC. The main risks in the United States are cirrhosis of the liver and non-alcoholic fatty liver disease (NAFLD).
Viral hepatitis. Hepatitis viruses are viruses that infect the liver. Two common types are hepatitis B and hepatitis C. Less than half of people diagnosed with liver cancer in the United States have had a long-term hepatitis B or hepatitis C infection. However, viral hepatitis is the largest risk factor for this type of cancer worldwide. People who have the hepatitis B virus face up to a 100-times greater risk of developing HCC, although HCC usually develops several decades after infection.
Viral hepatitis can be passed from person to person through exposure to another person's blood or bodily fluids. This can happen through injury, by sharing needles during drug use, or by sexual contact. In the case of hepatitis B, an unborn baby or infant can get the virus if the mother has it, although this can be avoided by vaccinating the baby.
If you develop acute hepatitis B or C and then “clear the virus,” you have no increased risk of liver cancer. Only people who do not clear the virus, known as “carriers,” have an increased risk. Your doctor will be able to perform blood tests that tell if you have cleared the virus.
Cirrhosis. Cirrhosis develops when liver cells are damaged and are replaced by scar tissue. Most cirrhosis in the United States is caused by alcohol  abuse. Other causes are viral hepatitis (types B and C, as mentioned above), too much iron in the liver from a disease called hemochromatosis, and some other rare types of chronic liver disease.
Obesity, NAFLD, and diabetes. Obesity  causes fat to be deposited in the liver, which leads to a condition known as NAFLD. Over the past decade, strong evidence has emerged suggesting that NAFLD and diabetes, a related disorder, are increasingly important risk factors for HCC in the United States.
Age. In the United States, adult primary liver cancer occurs most often in people older than 60.
Gender. Men are more likely than women to develop this type of cancer.
Environmental factors. Some environmental factors may increase the risk of liver cancer, such as exposure to certain chemicals or eating food contaminated with aflatoxin. Aflatoxin is a toxin made by a mold that can grow on stored nuts and grains. There is less risk of this in the United States.
Risk factors are cumulative, meaning that having more than one risk factor increases the risk of developing liver cancer even more. For instance, a person who carries both hepatitis B and C has a higher risk than a person carrying one type of the virus.
Different factors cause different types of cancer. Researchers continue to look into what factors cause this type of cancer. Although there is no proven way to completely prevent this disease, you may be able to lower your risk. Talk with your doctor for more information about your personal risk of cancer.
In the United States, HCC can usually be avoided by preventing viral hepatitis and cirrhosis. A vaccine can protect healthy people from contracting hepatitis B. In fact, the U.S. Centers for Disease Control and Prevention recommends that all children should have this vaccination. There is no vaccine against hepatitis C, which is most often associated with current or previous intravenous (IV) drug abuse. Blood banks in the United States check donated blood to make sure that blood carrying the hepatitis viruses is not used.
Cirrhosis can be avoided by not abusing alcohol and preventing viral hepatitis. Most industrialized countries have regulations to protect people from cancer-causing chemicals. In the United States, such regulations have virtually eliminated these chemicals as a cause of HCC.
There is increasing evidence that certain medications can control chronic hepatitis B or C infection, and thereby reduce the inflammation and damage these viruses cause in the liver. There have been major advances in recent years in anti-viral therapy, particularly for chronic hepatitis C virus infection. This is likely to have a major positive impact on liver cancer prevention, particularly if taken before cirrhosis develops. For information these types of treatments, it is important to talk with a hepatologist. A hepatologist is a doctor who specializes in diseases of the liver.
Because NAFLD linked to obesity is becoming an increasingly important risk factor for HCC, people are also encouraged to follow established guidelines for good health, such as maintaining a healthy weight, eating a balanced diet, and participating in moderate physical activity. Your doctor can help you create an appropriate exercise plan based upon your needs, physical abilities, and fitness level.
The next section in this guide is Screening , and it explains how tests may find cancer before signs or symptoms appear. Or, use the menu on the side of your screen to choose another section to continue reading this guide.