Highly sensitive AFP‐L3% assay is useful for predicting recurrence of hepatocellular carcinoma after curative treatment pre‐ and postoperatively

Aim:  The micro‐total analysis system (µTAS), a fully automated immunoassay system using microchip capillary electrophoresis, is highly sensitive and able to quickly assay the AFP‐L3%. The clinical usefulness of this system was studied. Methods:  We retrospectively enrolled 250 patients who underwent curative treatment for primary hepatocellular carcinoma (HCC) (93 patients underwent hepatic resection and 157, radiofrequency ablation [RFA]). Results:  The sensitivity for µTAS AFP‐L3% was 40.3% at the cutoff value of 5% in a range of AFP less than 20 ng/mL where the conventional method was unable to determine AFP‐L3%. The sensitivity for AFP‐L3% remained high even at stage I and at tumor size less than 2 cm (42.5% and 46.0%, respectively). Recurrence rate of patients with AFP‐L3% greater than 5% was significantly higher than that of patients with less than 5% ( P  = 0.001). Furthermore, in resected patients, the postoperative AFP‐L3% remained elevated with value greater than 5% was related to HCC recurrence ( P  = 0.001). Multivariate analysis revealed that multiple tumors ( P  = 0.004), preoperative AFP‐L3% greater than 5% ( P  = 0.003), albumin less than 3.5 g/dL ( P  = 0.008), and RFA ( P  = 0.003) were significant prognostic factors of recurrence. Conclusions:  The µTAS was found to be a highly sensitive assay for AFP‐L3% in patients with curative treatment of HCC. A cutoff value of 5% was useful for predicting recurrence after the curative treatment and detecting small tumors and early stage HCC. Additionally, postoperative AFP‐L3% was found to be a prognostic factor of HCC recurrence.