Background: Patients with hepatocellular carcinoma (HCC) seropositive for lectin-reactive α-fetoprotein (AFP-L3) have a poor prognosis. However, there have been no studies of the clinicopathologic features of patients seronegative for both AFP and des-γ-carboxy prothrombin (DCP), and seropositive for AFP-L3 alone in comparison with other patients seropositive for AFP-L3.
Methods: Patients with primary malignant hepatic tumors seropositive for AFP-L3 who underwent hepatectomy (n = 84) were divided into four groups, and their clinicopathologic features were compared: (i) group A, seronegative for AFP <100 ng/mL and DCP <40 mAU/mL; (ii) group B, seropositive for AFP ≥100 ng/mL and seronegative for DCP; (iii) group C, seronegative for AFP and seropositive for DCP ≥40 mAU/mL; and (iv) group D, seropositive for AFP and DCP.
Results: Among the 14 group A patients seropositive for AFP-L3 alone with low AFP concentrations, three had intrahepatic cholangiocarcinoma (ICC), one had a cholangiolocellular carcinoma, one had combined HCC and ICC, and one had undifferentiated hepatic sarcoma. Group A had a higher incidence of non-HCC tumors (P < 0.001) and tumors derived from cholangiocytes (P < 0.001) than the other three groups. They also had a high frequency of poorly differentiated tumors and sarcomatous changes, and showed a poor prognosis.
Conclusions: Patients with primary malignant hepatic tumors seropositive for AFP-L3 alone with low AFP concentrations have unique clinicopathologic features. Thus, we should be aware of these patients and should measure AFP-L3 levels, at least once, even in those seronegative for both AFP and DCP.