Lens culinaris-agglutinin-reactive fraction of alpha-fetoprotein is a prognostic biomarker in atezolizumab plus bevacizumab for hepatocellular carcinoma.

[OBJECTIVE] This study aimed to evaluate the prognostic ability of the lens culinaris-agglutinin-reactive fraction of alpha-fetoprotein (AFP-L3) in atezolizumab plus bevacizumab combination therapy (ATZ/BV) for unresectable hepatocellular carcinoma (u-HCC).

[METHODS] The analysis included 78 u-HCC patients who were evaluated for early tumor response after 6 weeks of ATZ/BV. Positivity for tumor markers (TMs), including AFP, AFP-L3, and des-gamma-carboxy prothrombin (DCP), was defined as elevated values of AFP (≥100 ng/ml), AFP-L3 (≥10%), and DCP (≥100 mAU/ml), and the TM score was defined as the sum of the number of positive TMs. Early tumor response was defined as a response 6 weeks after the start of therapy.

[RESULTS] AFP-L3 was identified as an independent prognostic factor in multivariate analysis. The median overall survival (OS) times in the AFP-L3-negative and -positive groups were 23.3 and 9.5 months, respectively ( P  = 0.002). The OS times in the TM score 0-2 and score 3 were 13.8 and 8.2 months, respectively ( P  = 0.013). AFP-L3 was also an independent predictor of early disease control (DC). When the cutoff for AFP-L3 was set at 80%, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in predicting early DC were 94.4, 41.7, 78.5, 76.9, and 78.2%, respectively.

[CONCLUSION] AFP-L3 is a useful biomarker for predicting the response and prognosis of patients with ATZ/BV for u-HCC. AFP-L3 should be measured together with AFP and DCP levels.