Primary liver cancer: global epidemiology and main aetiological factors

Liver cell cancer is the most frequent primary liver cancer worldwide and it is among the most malignant of cancers whether judged by clinical development, prognosis or response to treatment. The high frequency of this cancer in countries with large populations, in sub-Saharan Africa, South East Asia and China, makes it globally one of the most common cancers. Recent research has incriminated aetiological factors which offer good possibilities for prevention. The most important of these is a relationship with Hepatitis B virus infection (HBV). The cancer is associated with the chronic carrier state of this infection acquired in the perinatal period or early infancy rather than in adult life. Vaccines against HBV have been developed and are widely available although expensive at the present time. The evidence justifying intervention is presented. The vaccines have been found effective and safe and strategies for prevention are being developed in many areas. As chemical carcinogens so frequently produce liver cell cancers in animal models, possible associations with the human disease have been sought for many years. Naturally occurring mucotoxins, the aflatoxins found on many staple foods in areas of high frequency of the cancer, are suspect and the evidence justifying preventive measures against food contamination is also presented. The prospects for prevention of this cancer are encouraging but will require careful evaluation over many years.