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ON THIS PAGE: You will find out more about what factors increase the chance of this type of cancer. To see other pages in this guide, use the colored boxes on the right side of your screen, or click “Next” at the bottom.
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. Chronic liver infection with the hepatitis B or hepatitis C virus is associated with less than half of liver cancers diagnosed in the United States; 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-fold increased risk of developing HCC, although HCC usually develops several decades after such an infection starts.
Viral hepatitis can be passed from person to person through exposure to another person's blood or bodily fluids 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 don’t clear the virus (those who become “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. 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 the related disorder diabetes) is an increasingly important risk factor 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, 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 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.
Prevention and Early Detection
Research continues to look into what factors cause liver cancer and what people can do to lower their personal risk. There is no proven way to completely prevent this disease, but there may be steps you can take to lower your cancer risk. Talk with your doctor if you have concerns about your personal risk of developing this type 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 (swelling) these viruses cause in the liver. This may reduce the risk of cancer, particularly if the medications are taken before cirrhosis develops. For information these types of treatments, it is important to talk with a hepatologist, 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.
If you know you have cirrhosis or other risk factors, it is extremely important to talk with your doctor about whether you should be regularly screened for liver cancer. Finding a cancer before any symptoms have developed will increase the chance of successful treatment. Hepatologists are the doctors with the most experience in screening for primary liver cancer. You may also see the term “surveillance” used to explain this, but this means the same as screening.
Choose “Next” (below, right) to continue reading this guide to learn about what symptoms this type of cancer can cause. Or, use the colored boxes located on the right side of your screen to visit any section.