Clinical utility of Lens culinaris agglutinin-reactive alpha-fetoprotein in small hepatocellular carcinoma: special reference to imaging diagnosis

Abstract

Background/Aims: Blood concentration levels of alpha-fetoprotein like the Lens culinaris agglutinin-reactive fraction (AFP-L3) are a useful marker for predicting the long-term prognosis of hepatocellular carcinoma. This study investigated the relationship between serum AFP-L3 and various imaging modalities. Methods: Sixty-three patients with small hepatocellular carcinomas ≤2 cm in diameter were studied. Serum AFP-L3 concentrations were measured by lectin-affinity electrophoresis coupled with antibody-affinity blotting and expressed as % AFP-L3 (the percent of AFP-L3 as total AFP). A clinical “cutoff level” of 10% was used in this study to indicate the presence of hepatocellular carcinoma. Selective hepatic intraarterial digital subtraction angiography (DSA), ultrasonographic angiography with carbon dioxide microbubbles (USAG), and computed tomography during arterial portography (CTAP) were performed to evaluate the hemodynamics of hepatic nodules. Results: Fourteen (22.2%) of the 63 patients were positive for % AFP-L3. The % AFP-L3 levels ( n=45, 4.4%) of patients with hypervascular tumors were significantly higher than those ( n=15, 0.0%) of patients with isovascular or hypovascular tumors as determined by USAG ( p=0.0061). The % AFP-L3 levels ( n=53, 4.4%) of patients with a negative portal blood supply were significantly higher than the % AFP-L3 levels ( n=7, 0.0%) of patients with a positive portal blood supply as determined by CTAP ( p=0.0140). The % AFP-L3 levels of patients with tumors with a long doubling time (DT) were significantly lower than for patients with tumors with a short DT ( p=0.0176). Conclusion: AFP-L3 is a positive indicator which may be more specific for small advanced hepatocellular carcinoma.