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.