Expression of bFGF, VEGF and c-met and their Correlation with Microvessel Density and Progression in Prostate Carcinoma

Background: Previously, we found angiogenesis measured as microvessel density (MVD) to be associated with both pathological stage and clinical outcome after radical prostatectomy (RP). In addition, we have shown that Vascular Endothelial Growth Factor (VEGF) is one of the important inducers of angiogenesis in prostate cancer (PC). The aim of this study was to investigate the expression of additional angiogenic factors, namely basic Fibroblast Growth Factor (bFGF) and the c-met receptor of Hepatocyte Growth Factor/Scatter Factor (HGF/SF) in PC. Materials and Methods: Ninety-eight paraffin-embedded RP specimens and 20 adjacent normal prostatic tissues were evaluated for factor VIII staining and microvessel counting. Expression of VEGF (n=55), bFGF (n=65) and c-met (n=66) was studied by immunohistochemistry. Results were correlated with pathological grade and stage, MVD and clinical outcome. Results: While adjacent benign tissue in RP specimens generally showed low MVD, VEGF-, bFGF- and c-met-expression, this was different in PC. All angiogenesis inducers were associated with stage while c-met as well as VEGF expression were associated with grade. Tumor progression was associated with grade and MVD. There was a clear correlation between VEGF and c-met expression and MVD. Conclusion: VEGF and c-met expression increase with tumor stage and grade, while bFGF expression increases only with tumor stage. In addition to VEGF, c-met seems to be important and clinically relevant to the induction of angiogenesis in PC. Both VEGF and c-met appear to influence tumor progression, mainly through their effect on MVD.