ANGIOGENESIS AND MALIGNANT-MELANOMA - ANGIOGENESIS IS RELATED TO THE DEVELOPMENT OF VERTICAL (TUMORIGENIC) GROWTH-PHASE

To study angiogenesis in early steps of melanoma progression, 113 cuta neous melanomas 1mm or less in thickness were stained with Ulex europa eus lectin. Vascular density was determined in the areas of greatest v ascularization. To avoid the effect of anatomic location, the quotient between vascular density at the tumor base and in normal skin (vascul ar ratio) was obtained in each case. Of these melanomas, 46 were immun ohistochemically stained for the presence of vascular endothelial grow th factor (VEGF). Positivity was scored from 1-4 by comparing staining of melanoma cells with keratinocytes. Vascular ratio values in vertic al growth phase melanomas were higher than those in radial growth phas e when counting per 200 or 400 magnification (2.29+/-1.3 and 2.48+/-1. 5 for vertical growth phase and 1.34+/-0.62 and 1.41+/-0.83 for radial growth phase melanomas, respectively). This difference was statistica lly significant (p<0.0001 and p<0.001 at x 200 and x 400, respectively ). Also, VEGF staining was stronger in vertical growth phase melanomas when compared with radial growth phase melanomas (Chi square, p<0.025 ). In conclusion, our findings suggest that angiogenesis and VEGF expr ession are associated with the development of vertical growth phase.