The expression of basic fibroblast growth factor and vascular endothelial growth factor in prostatic adenocarcinoma: correlation with neovascularization.

BACKGROUND: Neovascularization associated with tumor invasion and metastasis may be stimulated by factors which are released from tumor cells, tumor-associated inflammatory cells or extracellular matrix. Although basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) have been characterized as promoters of angiogenesis, their precise localization in prostatic adenocarcinoma remains unclear.
MATERIALS AND METHODS: In this study, the immunohistochemical expression of the growth factors and their receptors were studied using paraffin-embedded archival tissues before and after neoadjuvant hormonal therapy. The mRNA expression of the growth factors was also examined using an in situ hybridization (ISH) technique.
RESULTS: The ISH study demonstrated that bFGF mRNA was present only in the stromal cells whilst that VEGF mRNA was present only in the adenocarcinoma cells. In contrast, the immunohistochemical study showed that bFGF, FGF receptor, VEGF and VEGF receptor proteins were expressed in adenocarcinoma cells and in endothelial cells. We also observed that microvessel density in prostatic adenocarcinoma was correlated with the degree of the expression of growth factors in the cases without neoadjuvant hormonal therapy. Additionally, the expression of those receptor proteins were much frequently identified in the cases with neoadjuvant hormonal therapy than those without it, while virtually no change in the expression of ligands was observed between the cases without and with neoadjuvant therapies.
CONCLUSIONS: In prostatic adenocarcinoma, bFGF and VEGF may correlate with neovascularization through each characteristic pathway. In addition, we assumed that neoadjuvant hormonal therapy may have minimal inhibitory effects on bFGF, VEGF and their receptors.