Serum endostatin predicts tumor vascularity in hepatocellular carcinoma

BACKGROUND. Tumor angiogenesis is a strong prognostic factor in patients with hepatocellular carcinoma (HCC). However, to the authors' knowledge, details regarding the serum levels of proangiogenic and antiangiogenic growth factors controlling this process are not yet known. METHODS. Serum endostatin, vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF) levels were measured by the enzyme immunoassay method in prospectively collected samples from 33 HCC patients who had received no preoperative therapy. The angiogenic score (AS) and endostatin localization were evaluated using immunohistochemistry. RESULTS. Significant decreases in serum endostatin (P = 0.0007) and bFGF (P = 0.0004) were observed in postoperative samples compared with the preoperative values. A very strong direct correlation was noted between VEGF and endostatin (P < 0.0001). Only the preoperative serum endostatin was found to have a significant (P = 0.0025) inverse correlation with the AS. Furthermore, the combined positivity for bFGF and VEGF and negativity for endostatin was found to have a significantly (P = 0.0069) positive correlation with AS. Significantly high levels of endostatin were noted in patients with trabecular-type tumors (P = 0.0446) and in patients with hepatitis B infection (P = 0.0183). The serum endostatin level was found to be significantly (P = 0.0166) higher in living patients and patients with high serum endostatin levels had a tendency (P = 0.0871) toward long survival. Tissue endostatin expression was found to have a direct correlation with the serum endostatin level (P = 0.0117). CONCLUSIONS. The measurement of serum endostatin can predict tumor vascularity and may serve as a promising tool in the antiangiogenic therapy for patients with HCC.