READ THIS NEXT: This Popular Party Snack May Cause Colon Cancer, Experts Say.ae0fcc31ae342fd3a1346ebb1f342fcb According to the Mayo Clinic, several factors may increase your risk of liver cancer. These include certain underlying conditions such as cirrhosis of the liver, inherited liver disease, diabetes, and nonalcoholic fatty liver disease. Additionally, individuals who drink excessive alcohol or are exposed to aflatoxins (a type of poison produced by improperly-stored crops) may also be at increased risk of liver cancer. However, these risk factors combined account for less than half of all liver cancer cases. READ THIS NEXT: If You Notice This on Your Face, Get Checked for Cancer. Experts say one liver cancer risk factor surpasses all others. “Worldwide, the most significant risk factor for liver cancer is chronic infection with hepatitis B virus (HBV) and hepatitis C virus (HCV),” explains the American Cancer Society. According to a report from the Centers for Disease Control and Prevention (CDC), roughly 65 percent of liver cancer cases in the U.S. are related to hepatitis B or C, and almost half of liver cancer cases are attributable to hepatitis C alone. You may be exposed to hepatitis B or C in several different ways. “These viruses can spread from person to person through sharing contaminated needles (such as in drug use), through unprotected sex, and through childbirth, so some liver cancers may be avoided by not sharing needles and by using safer sex practices (such as always using condoms),” explains ACS. Once a major source of hepatitis infection, blood transfusions are no longer considered a significant risk in the U.S. “Blood banks in the United States test donated blood to look for these viruses,” says ACS, noting that now “the risk of getting a hepatitis infection from a blood transfusion is extremely low.” For more health news sent directly to your inbox, sign up for our daily newsletter. The CDC recommends that “all children and adults up to age 59, as well as older adults at risk for HBV, get the HBV vaccine to reduce the risk of hepatitis and liver cancer.” While there is currently no vaccine for hepatitis C, treatments options are able to cure over 85 percent of cases. Testing for hepatitis C is crucial, since over half of cases are asymptomatic and go undetected. “For years, even decades, hepatitis C can slowly and silently damage the liver, leading to cancer and other serious health consequences,” says the CDC report. Successful treatment, which takes just months to complete, “reduces liver cancer risk by 75 percent,” it explains.