Serum endocan as a novel prognostic biomarker in patients with hepatocellular carcinoma

Endocan is a vascular endothelium-derived factor regulated by angiogenic factors. The aim of this study was to determine whether serum endocan levels are prognostic for survival in patients with hepatocellular carcinoma (HCC). Serum endocan levels were measured in 64 HCC patients who were naïve to treatment, eight apparently healthy subjects, and 68 patients with liver cirrhosis; the latter two groups served as controls. Prognostic factors for the survival of HCC patients were examined using a Cox proportional hazards model. The median serum endocan levels were 1.145 ng/mL (range, 0.93-1.68 ng/mL) in healthy subjects, 1.93 ng/mL (range, 0.45-8.47 ng/mL) in liver cirrhosis patients, and 3.73 ng/mL (range, 0.74-10.95 ng/mL) in HCC patients (P = 0.0001). In HCC patients, elevated serum endocan levels were significantly associated with poor hepatic function (P = 0.015), a greater number of tumors (P = 0.034), and vascular invasion (P = 0.043). The median follow-up period was 23.0 months, and 33 HCC patients died during follow up. Multivariate analysis showed that serum endocan levels ≥ 2.20 ng/mL (hazard ratio 2.36, 95% confidence interval 1.22-5.36, P = 0.008) as well as elevated serum α-fetoprotein and des-γ-carboxy prothrombin levels were independent prognostic biomarkers for poor survival. The combination of serum endocan and these two additional markers was significantly predictive of worse survival (P < 0.0001). Thus, serum endocan may be a prognostic biomarker for survival in HCC patients, and the combination of serum endocan, α-fetoprotein, and des-γ-carboxy prothrombin levels can result in better prognostic stratification of these patients.