Hepatocarcinogenesis in chronic hepatitis C patients achieving a sustained virological response to interferon: significance of lifelong periodic cancer screening for improving outcomes
α-fetoprotein (AFP) is a tumor marker of hepatocellular carcinoma (HCC) and has also been reported to reflect the effectiveness of long-term low-dose interferon (IFN) therapy in hepatitis C virus (HCV)-infected patients with chronic liver disease. The correlation between AFP levels and the incidence of HCC has been discussed over a long period. We investigated whether high levels of AFP at the time of diagnosis were associated with an increased incidence of HCC in patients with HCV. A total of 107 HCV patients with liver cirrhosis without other risks were evaluated for the predictive value of non-invasive risk factors for HCC, including age, gender, alcohol intake, aspartate and alanine aminotransferase levels, bilirubin, albumin, platelet count and AFP levels at study entry, as well as the IFN therapy received. During the follow-up period, HCC developed in 68 (63.6%) patients. Kaplan-Meier estimates were made to assess the cumulative risk of HCC. The 10-year cumulative incidence rate of HCC was 80%. Cox regression analysis was performed on several variables, including age, gender, alcohol consumption, experience of IFN therapy and biochemical parameters. The following factors were identified as exhibiting an increased risk of HCC by univariate analysis: aspartate transaminase (AST) ≥71 IU/l, alanine transaminase (ALT) ≥60 IU/l, AFP ≥6 ng/ml and IFN therapy. Multivariate analysis identified that the AFP level [6‐19 ng/ml: hazard ratio (HR), 2.22; P=0.006 and ≥20 ng/ml: HR, 2.09; P=0.003] was an independent and significant risk factor for the development of HCC. A slightly elevated (6-19 ng/ml) AFP level may be a risk factor for HCC in certain cases. By contrast, AFP levels <6 ng/ml indicate a low risk of HCC development in HCV patients with liver cirrhosis.