Background and Aim: The Lens culinaris agglutinin-reactive fraction of α-fetoprotein (AFP-L3) has been reported to be a highly useful marker for hepatocellular carcinoma (HCC) compared with a conventional serum AFP concentration, which allows earlier detection of HCC compared with using other imaging modalities and predicting prognosis after therapy. A collaborative prospective study involving nine Japanese hospitals was conducted to analyze the relationships between the tumor characteristics of a HCC patient and the percentage of AFP-L3/AFP total at the initial detection.
Methods: Between 1 October 1996 and 30 September 1997, a total of 388 patients with newly diagnosed HCC were registered.
Results: The cut-off level of the percentage of AFP-L3 was altered from 15 to 10%. The AFP-L3-positive HCC patients demonstrated the characteristics of having an advanced tumor, such as the number of tumors, maximum diameter, tumor spread, portal vein invasion, tumor stage, and tumor classification. With the conventional cut-off level of 15% of the percentage of AFP-L3, the malignant characteristics were more definite than that of 10%. However, no significant differences of serum AFP concentration were observed for malignant characteristics such as maximum diameter and histopathological grading.
Conclusion: Serum AFP concentration does not reveal a malignancy of HCC, however, the AFP-L3-positive HCC has biologically malignant characteristics, especially portal vein invasion and lower tumor classification, and is an advanced tumor regardless of small tumor size and lower serum AFP concentration. As AFP-L3 shows the tumor characteristics, its presence should be an important factor in the determination of therapy and prognosis of patients.