Co-expression of VEGF and bFGF is associated with increased microvessel density in head and neck squamous cell carcinoma.

Background: Angiogenesis is crucial for tumor growth and metastasis. In sev eral tumors, microvascular density has been shown to correlate with metasta sis and aggressiveness. Vascular endothelial growth factor (VEGF) and basic Fibroblast Growth Factor (bFCF) are known to have potent angiogenic activi ty. Their expression has been identified in a wide variety of malignancies including head and neck squamous cell carcinoma (HNSCC). Aim of our study w as to investigate the role of co-expression of VEGF and bFGF for angiogenes is in HNSCC. Material and Methods: Cryostat sections of 51 primary HNSCC we re immunostained for VEGF and bFGF using a standard streptavidin-biotin com plex procedure. To evaluate angiogenesis, endothelial cells were stained im munohistochemically using anti-vWF polyclonal antibody. Microvessels were q uantified by counting vessels in a x 200 field in the most vascular area of the tumor. Results: 25/51 (49%) of the investigated carcinomas showed co-e xpression of both factors (VEGF+/bFGF+), while 6/51 (11.7%) carcinomas only expressed VEGF and 13/51 (25.5%) carcinomas expressed bFGF. 7/51 (13.7%) t umors showed no expression of these factors (VEGF-/bFGF-). Carcinomas with a co-expression of VEGF and bFGF showed a significantly increased mean micr ovessel density (88.3 +/- 24.4) compared to tumors expressing only VEGF (77 +/- 16.8) or bFGF (71.1 +/- 15.8) (p = 0.022) or tumors with no expression of both factors (51.1 +/- 13.4) (p < 0.001). The association of VEGF and b FGF expression level was not significant (p = 0.178). Conclusions: The posi tive correlation of the co-expression of angiogenic VEGF and bFGF with incr eased microvessel density underlines the importance of both factors for tum or angiogenesis in HNSCC. VEGF and bFGF might act cooperatively in the proc ess of neovascularization in human head and neck cancer.