Clinical significance of the highly sensitive fucosylated fraction of α‐fetoprotein in patients with chronic liver disease

Background and Aim:  The purpose of the present study was to investigate the clinical significance of the highly sensitive fucosylated fraction of α-fetoprotein (hs-AFP-L3) in patients with chronic liver disease (CLD) and low serum α-fetoprotein (AFP) concentration. Methods:  A total of 241 patients being treated at our institute with CLD and low serum AFP concentration (3–10 ng/mL) were investigated retrospectively. We measured total AFP and the percentage of AFP-L3 using a µTAS Wako i30 device. The possible presence of hepatocellular carcinoma (HCC) was thoroughly investigated by various examinations carried out from 1 month before to 1 month after measurements. In addition, hs-AFP-L3 elevated and non-elevated groups, divided by the cut-off value based on a receiver–operator characteristic (ROC) curve, were followed for possible future development of HCC. Results:  hs-AFP-L3 was above the detectable range in 60 patients (24.9%). Among those AFP-L3 positive cases, 20 (33.3%) were found to be HCC prevalent, whereas HCC was found in just 16 patients (8.8%) with undetectable hs-AFP-L3 levels. We determined the cut-off value of hs-AFP-L3%, which shows the proportion of AFP L3 in total AFP, to be 5.75%. During the follow-up period, HCC was newly detected in six patients (22.2%) in the hs-AFP-L3% elevated group and in 10 (5.6%) in the non-elevated group. Analysis using the Kaplan–Meier method showed the HCC-free rate of the hs-AFP-L3% elevated group was significantly lower than that of the non-elevated group (P = 0.0038). Independent predicting variants were female sex (P = 0.0024) and hs-AFP-L3% elevation (P = 0.0036). Conclusion:  Our results suggest hs-AFP-L3 level is a useful tumor marker for HCC in patients with CLD and low serum AFP concentration.