Prevalence and risk factors

The association between HCV and HCC predates the discovery of the virus, since early on it had been shown that there was a close relationship between NANBH and the development of HCC (Kiyosawa et al., 1982, 1984, 1990; Sakamoto et al., 1988). However, once HCV was discovered (Choo et al., 1989) and serological assays became available for its detection (Kuo et al., 1989) (Sections 1.4 and 1.5), a close association was established between anti-HCV and HCC all over the world (Bruix et al., 1989; Colombo et al., 1989; Hasan et al., 1990; Kew et al., 1990; Saito et al., 1990; Vargas, Costella & Esteban, 1990; Yu et al., 1990; Sulaiman et al., 1991). In southern Europe and Japan, for example, more than half of the reported HCC has been associated with HCV (Bruix et al., 1989; Colombo et al., 1989) whereas the prevalence of anti-HCV in Alaskan patients with HCC is nearly zero. Intermediate frequencies of anti-HCV have been reported among patients from Greece, Austria, and Taiwan (Jeng & Tsai, 1991; Baur et al., 1992; Hadziyannis et al., 1993), indicating geographic variation in this association. Worldwide, there are an estimated 170 million people who are chronically infected with HCV (Bradley et al., 1983; Choo et al., 1989; Houghton, 1996; Delwaide & Gerard, 2000; Wild & Hall, 2000) (Section 3.1), and the annual incidence rate of newly diagnosed HCC associated with HCV infection ranges from 1 to 7% in different populations (Di Bisceglie, 1997).