Prediction model of hepatocarcinogenesis for patients with hepatitis C virus-related cirrhosis. Validation with internal and external cohorts.

To estimate hepatocarcinogenesis rates in patients with hepatitis C virus (HCV)-related cirrhosis, an accurate prediction table was created.A total of 183 patients between 1974 and 1990 were assessed for carcinogenesis rate and risk factors. Predicted carcinogenesis rates were validated using a cohort from the same hospital between 1991 and 2003 (n=302) and an external cohort from Tokyo National Hospital between 1975 and 2002 (n=205).The carcinogenesis rates in the primary cohort were 28.9% at the 5th year and 54.0% at the 10th year. A proportional hazard model identified alpha-fetoprotein (>or=20 ng/ml, hazard ratio 2.30, 95% confidence interval 1.55-3.42), age (>or=55 years, 2.02, 95% CI 1.32-3.08), gender (male, 1.58, 95% CI 1.05-2.38), and platelet count (<100,000 counts/mm3, 1.54, 95% CI 1.04-2.28) as independently associated with carcinogenesis. When carcinogenesis rates were simulated in 16 conditions according to four binary variables, the 5th- and 10th-year rates varied from 9 to 64%, and 21-93%, respectively. Actual carcinogenesis rates in the internal and external validation cohorts were similar to those of the simulated curves.Simulated carcinogenesis rates were applicable to patients with HCV-related cirrhosis. Since, hepatocarcinogenesis rates markedly varied among patients depending on background features, we should consider stratifying them for cancer screening and cancer prevention programs.