Role of alpha-fetoprotein in the diagnosis and management of hepatocellular carcinoma.

Thirty-five years after its first description, alpha-fetoprotein (AFP) remains the gold standard by which other markers are judged. Serum levels above the reference range of 10 ng/mL occur in approximately 75% of cases of hepatocellular carcinoma (HCC). In individual patients, the serum AFP level behaves as if it reflects tumour mass. However, the specificity of AFP is relatively low because moderately raised levels are also found in some patients with uncomplicated chronic liver disease. Recently, tumour-specific AFP assays have been developed. These are based on the carbohydrate side-chains on the AFP molecule which exhibit characteristic differences in AFP of different origins. Monitoring response to treatment may often be more effectively carried out by serial estimation of AFP than by conventional imaging techniques. The relative specificity of AFP for HCC has also been employed to detect circulating HCC cells and to target gene therapy.