Influence of tumor thickness and vascularity on survival in cutaneous melanoma.

Eighty-eight cases of cutaneous melanoma (CM) were analyzed in order to elucidate the relationship between thickness, angiogenesis, and prognosis. The thickness of the tumor was measured according to the Breslow method, and the microvessels were identified by an immunohistochemical study using anti-factor VIII monoclonal antibody on specimens from 40 patients with superficial spreading melanoma (SSM), and 48 with nodular type (NM). Microvessels were counted in the area of highest density. The overall survival and disease-free period were analyzed retrospectively. The proportion of patients with thicker CMs (> 1.5 mm) increased with age in both sexes. Mean vascular count was statistically significant different only between thinner and thicker tumors in the SSM group (P < 0.05). Prognosis was correlated with the thickness of CM (P = 0.0002), mean vascular count alone (P = 0.004), mean vascular count in association with CM thickness less than 1.5 mm (P = 0.0005), and with mean vascular count in NM (P = 0.02). These findings suggest that increasing microvessel density indicates a worsening prognosis.