Epidemiology and early diagnosis of primary liver cancer in China.

Epidemiological studies in different areas in China have revealed several outstanding risk factors of PLC, i.e., HBV infection, pollution of drinking water, contamination of food by AFB1 and/or nitrosamines, and family predisposition. Accordingly, a program of HBV vaccination, improved supply of drinking water, better preservation and storage of food, and possibly chemoprevention for high-risk populations should be effective preventive measures. Studies have shown that frequent AFP screening in high-risk populations is highly recommended to detect early cases of PLC. According to research in Qidong, careful follow-up of the dynamic changes of AFP in individuals with persistent low levels of positive AFP is important for distinguishing other conditions from true PLC. Newer means for the localization of small-size PLC (under 5 cm), such as type B ultrasonography, nuclide scanning, computerized tomography, and hepatoangiography, represent remarkable progress in improving markedly the success of surgery and hence the survival rate of PLC patients. The advances in knowledge of PLC have been encouraging. Although much work remains to be done on the etiological agents and the mechanism of oncogenesis, it is time that larger scale control measures be put into effect in high-incidence areas to discover if one of the most common cancers in the world can be controlled.