AFP-L3 and DCP strongly predict early hepatocellular carcinoma recurrence after liver transplantation

Abstract

Background & aims: Alpha-fetoprotein (AFP) predicts hepatocellular carcinoma (HCC) recurrence after liver transplant (LT) but remains an imperfect biomarker. The role of DCP (des-gamma-carboxyprothrombin) and AFP-L3 (AFP bound to Lens culinaris agglutinin) in predicting HCC recurrence remains incompletely characterized. AFP-L3 and DCP could identify patients at high risk of post-transplant HCC recurrence and serve as liver transplant exclusion criteria to defer transplant until patients receive additional risk-reducing pre-transplant locoregional therapy.

Methods: This prospective cohort study included consecutive patients with HCC who underwent LT (within or down-staged to Milan criteria) between 2017 and 2022. Pre-transplant AFP, AFP-L3, and DCP measurements were obtained. The primary endpoint was the ability of biomarkers to predict HCC recurrence-free survival.

Results: This cohort included 285 patients with a median age of 67 (IQR 63-71). At LT, median biomarker values were AFP 5.0 ng/ml (IQR 3.0-12.1), AFP-L3 6.7% (0.5-13.2), and DCP 1.0 ng/ml (0.3-2.8). Most (94.7%) patients received pre-LT locoregional therapy. After a median post-LT follow-up of 3.1 years, HCC recurrence was observed in 18 (6.3%) patients. AFP-L3 and DCP outperformed AFP with C-statistics of 0.81 and 0.86 respectively, compared with 0.74 for AFP. A dual-biomarker combination of AFP-L3 ≥15% and DCP ≥7.5 predicted 61.1% of HCC recurrences, whereas HCC only recurred in 7 of 265 (2.6%) patients not meeting this threshold. The Kaplan-Meier recurrence-free survival rate at 3 years post-LT was 43.7% for patients with dual-positive biomarkers compared to 97.0% for all others (p <0.001).

Conclusions: Dual-positivity for AFP-L3 ≥15% and DCP ≥7.5 strongly predicted post-LT HCC recurrence. This model could refine LT selection criteria and identify high-risk patients who require additional locoregional therapy prior to LT.

Impact and implications: Alpha-fetoprotein (AFP) is used to predict hepatocellular carcinoma (HCC) recurrence after liver transplant, but it remains an imperfect biomarker. In this prospective study, the biomarkers DCP (des-gamma-carboxyprothrombin) and AFP-L3 (AFP bound to Lens culinaris agglutinin) strongly predicted early HCC recurrence and outperformed AFP. A dual-biomarker combination of AFP-L3 ≥15% and DCP ≥7.5 predicted the majority of recurrences and could be used to further refine liver transplant eligibility criteria.

Keywords: AFP-L3; alpha fetoprotein (AFP); des-gamma-carboxyprothrombin (DCP); hepatocellular carcinoma (HCC); liver transplant (LT).