Epidemiology Unit, National Cancer Institute, Napoli, Italy.
Hepatocellular carcinoma is the most common primary liver malignancy and is an international public health concern, constituting one of the most deadly cancers worldwide. Infection with hepatitis B virus and hepatitis C virus is a major risk factor for HCC in developed countries. Emerging evidence indicates that there are other important lifestyle factors that contribute to the international burden of HCC, such as alcohol consumption, diabetes, obesity, and the intake of aflotoxin-contaminated food. Obesity and diabetes are also likely to be risk factors for HCC, the most frequent subtype of liver cancer. The chief pathway by which obesity increases risk involves the association between obesity and nonalcoholic fatty liver disease (NAFLD). Coffee consumption has been studied extensively and appears to have a favorable effect on the prevention of liver diseases, including HCC. One hypothesis suggests that coffee intake lowers serum levels of gamma-glutamyltransferase (GGT), which is associated with a lower incidence of HCC. It is estimated that more than 80% of HCC cases are attributable to four principal causes that are avoidable. It is difficult to make dietary recommendations, because it is unknown whether consuming higher amounts of specific antioxidants will decrease the risk of developing hepatocellular carcinoma. A diet rich that is in polyunsaturated fatty acids and, possibly, B-carotene could reduce the risk of HCC, and high dietary GL is associated with an increased risk independently of cirrhosis or diabetes.