TUMOR ANGIOGENESIS CORRELATES WITH LYMPH-NODE METASTASES IN INVASIVE BLADDER-CANCER

Neovascularization of tumor tissue (tumor angiogenesis) is considered essential for tumor growth, proliferation and eventually metastasis. M icrovessel density or count, a measure of tumor angiogenesis, correlat es with clinical outcome in skin, breast, lung and prostate carcinomas . To determine whether an association of tumor angiogenesis and nodal metastasis exists in invasive bladder cancer, microvessel counts in 41 primary invasive stages (T2 to 4,NX,M0) bladder cancers were assessed . Microvessels were identified by immunostaining of endothelial cells for factor VIII-related antigen. Microvessels were scored in selected areas showing active neovascularization, either counting a 200 x field (0.74 mm.(2)) or by using a 10 x 10 square ocular grid (0.16 mm.(2)). The microvessel count correlated with the presence of occult lymph no de metastases (p < 0.0001) by both techniques. The mean microvessel co unt in 27 patients without lymph node metastases was 56.2 microvessels per 200 x field (standard deviation [SD] 29.5, range 7 to 130) or 28. 6 microvessels per grid (SD 14.4, range 4 to 65). The 14 patients with histologically proved lymph node metastases showed mean 138.1 microve ssels per 200 x field (SD 37.9, range 82 to 202) or 74.7 microvessels per grid (SD 14.4, range 43 to 115). Good correlation was noted betwee n area and grid counting (r = 0.97). Tumor T stage, grade and the pres ence of vascular or lymphatic invasion did not correlate with the pres ence of lymph node metastases (p = 0.41, 0.59 and 0.26, respectively). Microvessel count may provide important information regarding the ris k of occult metastasis in patients with invasive bladder carcinomas.