Clinical significance of lens culinaris agglutinin-reactive fraction of serum α-fetoprotein in patients with hepatocellular carcinoma

α-fetoprotein (AFP) is an important marker for the diagnosis of hepatocellular carcinoma (HCC) and has been widely used in clinical settings. Recently, the importance of lens culinaris agglutinin-reactive fraction of AFP (AFP-L3) has been indicated. However, the clinical significance of the level of AFP-L3 protein in relation to the characteristics of HCC has not been fully evaluated. In the present study, both the ratio of AFP-L3 (AFP-L3%) and the absolute value of AFP-L3 (AFP-L3-AV) were examined in 80 patients with HCC, and evaluated with respect to characteristics of HCC such as grade of differentiation, size of tumor and morphological findings. Among HCC-specific tumor markers, AFP, AFP-L3% and protein induced in vitamin K absence (PIVKA-II), AFP showed the highest positive rate in patients with HCC, while AFP-L3% showed the lowest rate. AFP-L3% and AFP-L3-AV were, however, most significantly correlated with the grade of HCC differentiation, while AFP showed the least significant correlation. Furthermore, AFP-L3% was most significantly correlated with the size of HCC in patients with solitary HCC. Conversely, neither AFP-L3-AV nor PIVKA-II showed a significant correlation with the size of HCC. In relation to morphological differences of HCC, although AFP-L3%, AFP-L3-AV and PIVKA-II were significantly higher in the diffuse type of HCC than in the nodular type of HCC, AFP was most significantly correlated with the morphological differences of HCC. These results indicate that tumor markers for HCC, such as AFP, AFP-L3%, AFP-L3-AV and PIVKA-II, may play different roles in predicting the characteristics of HCC.