Assessment of angiogenesis in human cervical lesions

Angiogenesis has been extensively studied in several types of invasive carcinomas and has been correlated-with tumor growth and metastasis. In some of these studies it has been shown that angiogenesis preceeds neoplastic transformation. A correlation is evident between microvessel density and conditions that exist much before the onset of tumor formation (i.e. dysplastic lesions). In this study, tumor vascularity was quantified in a series of cervical lesions: 92 dysplasias (31 mild, 24 moderate and 36 severe) and 11 infiltrating squamous cell carcinomas. Microvessels were visualized by a polyclonal antibody against factor VIII-related antigen (DAKO), using a streptavidin-peroxidase immunohistochemical method. Vessel density was quantified in 3 high power fields (hpf) of the most vascular areas, by two independent observers. Mean vascular counts were 13 +/- 5 vessels per unit area in CIN I lesions, 17 +/- 4 in CIN II, 20 +/- 6 vessels in CIN III and 17 +/- 5 in infiltrating carcinomas. There was a progressive increase of vascularity in the dysplastic lesion in the samples with increasing atypia in relation to controls. No significant differences were noted between severe cervical dysplasias and infiltrating carcinomas. Our findings suggest that angiogenesis may be an important event in tumor initiation and the conversion of the normal epithelium into cancer.