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.