Liver cancer: incidence, mortality and risk factors

Liver cancer (LC) is one of the most frequent cancers worldwide and the first one that can be prevented by vaccination against hepatitis B virus and screening of hepatitis C virus in blood and its derivatives. During 2002, it has been estimated that there were 626 162 new cases of LC diagnosed worldwide. The high risk areas for LC are located in Southeastern Asia and in some Central and Western African countries, whereas low risk areas are located in Northern Europe, Australia, New Zealand and the Caucasian population of America. LC incidence in high risk countries is between 2 and 3-fold higher than that of the low-risk countries. This geographical variability suggests that some environmental factors play an important role in the etiology of this tumor. The attributable risk of hepatitis B and C virus is about 80%. Alcohol consumption, aflatoxins and oral contraceptives could partially explain the residual variability of the LC incidence. Other emerging factors associated to LC, such as obesity and diabetes, might also play an important role in developed countries.