The exact cause of hepatocellular carcinoma is unknown; however, the disease is thought to have more than one cause.
Several risk factors increase the chances of developing hepatocellular carcinoma, such as chronic hepatitis B virus (HBV) infection or chronic hepatitis C virus (HCV) infection, both of which cause cirrhosis (liver scarring/fibrosis) that can develop into hepatocellular carcinoma, excessive alcohol intake, and fatty liver diseases, such as non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (severe fatty liver disease; NASH).
Smoking cigarettes is a major risk factor, while obesity and diabetes are additional lower-risk factors for developing hepatocellular carcinoma.
Eating foods with aflatoxins, which fungi produce, exposure to chemicals, such as vinyl chloride and Thorotrast (previously used in X-rays), using anabolic steroids, exposure to arsenic, exposure to parasites (schistosomiasis) in Asia, Africa, and South America, having a rare metabolic or genetic disorder, such as autoimmune hepatitis, alpha-1 antitrypsin deficiency, hemochromatosis, porphyria cutanea tarda, primary biliary cholangitis, tyrosinemia, Wilson’s disease, hemochromatosis, or being of certain races/ethnicities, such as Asian American, Pacific Islander, American Indian, Alaska Native, Hispanic/Latinos, or African American, all increase the risk of hepatocellular cancer.
High rates of hepatitis B virus (HBV) infection in Asia have increased the rates of hepatocellular cancer in those countries. In the U.S., hepatitis C virus more commonly leads to hepatocellular carcinoma.
Metabolic syndrome and non-alcoholic fatty liver disease (NAFLD) are also associated with obesity and are a significant cause of hepatocellular carcinoma. It is estimated that nearly 30% of Americans have non-alcoholic fatty liver disease, which can then become a severe form of fatty liver disease known as non-alcoholic steatohepatitis (NASH). In turn, non-alcoholic steatohepatitis can develop into hepatocellular carcinoma.