Coexpression of VEGF and bFGF in human epidermoid lung carcinoma is associated with increased vessel density

Tumor specimens from 84 patients with untreated epidermoid lung carcinomas were analysed immunohistochemically for the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), tumor cell proliferation (PCNA index) and tumor vascularity (vessel density). The purpose of this study was to find out whether differences in tumor cell proliferation and tumor vascularity might be associated with differential angiogenic growth factor expression. The present results indicate that the proliferation of the tumors is closely related to their expression of VEGF, but not for bFGF. The PCNA labelling index in VEGF positive tumors (VEGF+/bFGF- or VEGF+/bFGF+) was significantly higher than that in VEGF negative tumors (VEGF-/bFGF- or VEGF-/bFGF+; Wilcaxon rank sum test, p < 0.0001). To investigate whether VEGF or bFGF is involved in lung tumor angiogenesis, the data of VEGF and bFGF expression were correlated with vessel density. It was found that the expression of VEGF and bFGF were associated with increment of vessel density, however, vessel density was significantly increased only when VEGF and bFGF were coexpressed (p < 0.02). It is suggested that VEGF and bFGF might act cooperatively in the neovascularization of human epidermoid lung carcinomas.