While the exact cause of primary liver cancer is unknown, risk factors include viral hepatitis B (HBV) and C (HCV), cirrhosis, alcohol use, exposure toxins and intake of anabolic steroids. The most common cause of liver cancer worldwide, is chronic infection with the hepatitis B virus. In the United States, more than 4 million individuals have chronic hepatitis C infection which is responsible for the majority of primary liver cancers. Approximately 20 percent of HCV patients will eventually develop cirrhosis of the liver and approximately one to two percent of these patients will develop HCC. Most Americans have become infected with HCV as a result of contaminated blood supplies before 1992 - the year improved blood supply screening tests became available. HBV and HCV are also commonly transmitted through unprotected sex, contaminated drug paraphernalia and unsterile needles used in body piercing and tattoos.

While liver cancer can affect people of all ages and races, certain factors may increase your risk. These include:

Age

Liver cancer occurs more commonly in people age 60 and over.

Sex

Liver cancers occur twice as often in men than in women.

Race

The highest rates of liver cancer in the United States occurs among Asian-Americans due to high rates of chronic hepatitis B infection. American blacks and Hispanics are the next highest groups to develop liver cancer, followed by whites.

Chronic infection with HBV or HCV

The greatest risk factor for liver cancer is chronic infection with hepatitis B or C. HBV is associated with the majority of cases of HCC worldwide. In the United States, hepatitis C is the greatest risk factor.

Diabetes

Having diabetes increases your risk for developing liver cancer compared to individuals without diabetes. Having both hepatitis C and diabetes increases your risk even more.

Cirrhosis

Cirrhosis is a progressive and irreversible condition that causes scar tissue to form in your liver and increases your risk for developing liver cancer.

Gene mutations

Today we know that women with mutations in the BRCA1 and BRCA2 genes are at greater risk for developing breast and ovarian cancer than woman who don't have these genetic defects. Now it appears that these genes may also contribute to a slightly increased risk for developing primary liver cancer.

Exposure to aflatoxins

Eating foods contaminated with aflatoxins (carcinogenic toxins produced primarily in stored agricultural products like peanuts by molds) can greatly increase your risk for developing liver cancer.

Smoking

Smoking tobacco of any kind increases your chances that you will develop liver cancer.

Excessive alcohol consumption

Regularly consuming excessive amounts of alcohol can lead to irreversible liver damage and increase your risk of liver cancer. Moderate consumption is defined as no more than two drinks a day for men and women. A drink is considered a one 4-to5-ounce glass of wine, 12 ounces of beer or a 1.5-ounce shot of 80-proof distilled spirits.