Utility of the FIB-4 Index for hepatocarcinogenesis in hepatitis C virus carriers with normal alanine aminotransferase levels

The FIB-4 index is a simple formula using age, aspartate aminotransferase, alanine aminotransferase (ALT) and platelet count to evaluate liver fibrosis. We investigated the ability of the FIB-4 index for hepatocarcinogenesis in hepatitis C virus (HCV) carriers with normal ALT levels. A total of 516 patients with ALT levels persistently at or below 40IU/L during an observation period of over 3years were included. Factors associated with the development of HCC were determined. Hepatocellular carcinoma (HCC) developed in 60 of 516 patients (11.6%). The incidence rate of HCC at 5 and 10years was 2.6% and 17.6%, respectively. When patients were categorized according to the FIB-4 index as 2.0 (n=226), >2.0 and 4.0 (n=169), and >4.0 (n=121), the cumulative incidence of HCC at 5years was 0.5%, 1.3% and 8.0%, respectively, and 2.8%, 25.6% and 37.1% at 10years, respectively. Patients with FIB-4 index >4.0 were at the highest risk (P<0.001). Factors that were significantly associated with HCC in the multivariate analysis were FIB-4 index >2.0 (hazard ratio (HR), 7.690), FIB-4 index >4.0 (HR, 8.991), -fetoprotein (AFP) >5ng/mL (HR, 2.742), AFP >10ng/mL (HR, 4.915) and total bilirubin >1.2mg/dL (HR, 2.142). A scoring system for hepatocarcinogenesis that combines the FIB-4 index and AFP predicted patient outcomes with excellent discriminative ability. The FIB-4 index is strongly associated with the risk of HCC in HCV carriers with normal ALT levels.