THE ASSOCIATION BETWEEN TUMOR PROGRESSION AND VASCULARITY IN THE ORAL-MUCOSA

Tumourigenesis in experimental models is associated with the formation of new blood vessels (angiogenesis). Recent studies have suggested th at tumour angiogenic activity may be inferred in histological sections by measuring the density of the vasculature. The purpose of this stud y was to determine whether the transition from normal to dysplastic an d neoplastic tissue in the oral mucosa is accompanied by quantitative or qualitative changes in the vascularity of the tissue, and hom the e stimate of vascularity is influenced by the vessel marker and method o f assessment, A total of 100 specimens of normal oral mucosa, dysplast ic lesions, and squamous cell carcinomas mere examined. Sections were immunostained with the pan-endothelial antibodies to von Willebrand Fa ctor (VWF) and CD31, or with an antibody to the alpha(v) beta(3) integ rin, previously reported to be a marker of angiogenic vessels. Vascula rity Nas quantitated by tao different methods: highest microvascular d ensity (h-MVD) and microvascular volume, as determined by point counti ng (MVV). The results showed that vascularity, measured by the MVV met hod using antibodies to either vWF or CD31, increased significantly (P <0.0001) with disease progression from normal oral mucosa, through mil d, moderate, and severe dysplasia to early and late carcinoma (76 para ffin-embedded tissues examined), In contrast, h-MVD did not discrimina te between dysplastic lesions and carcinoma. A similar percentage of t he total vessel volume (MVV) and density (h-MVD) were positive for alp ha(v) beta(3) in 24 frozen tissues examined, including normal oral muc osa. It is concluded that there is a close association between vascula rity and tumour progression in the oral mucosa. Morphometric analysis reflecting microvascular volume is more informative than the currently popular analysis of microvascular density, The expression of alpha(v) beta(3) in the vasculature of oral tissues does not necessarily refle ct the presence of angiogenic vessels. (C) 1997 by John Wiley & Sons, Ltd.