PROGNOSTIC SIGNIFICANCE OF MICROVESSEL COUNT IN LOW STAGE RENAL CELL CARCINOMA

Abstract
It has been postulated that tumors beyond a certain size are dependent on angiogenesis, which might also be related to distant metastasis. We therefore assessed the prognostic significance of tumor microvasculature in renal cell carcinoma. Tumor specimens from 84 patients with primary renal cell carcinoma were examined by immunohistochemical staining for factor VIII. Individual microvessels were counted in a 200 x field overlying the area of highest neovacularization. The mean number of microvessels in patients with metastases was significantly higher than that in patients who were disease-free for more than three years (P = 0.004). The survival of patients with less than 30 microvessels per 200 x field was significantly higher than that of patients with more than 30 microvessels per 200 x field (P = 0.007). Multivariate analyses revealed that these microvessel counts were the only significant predictor of prognosis in 45 patients with T1-2 and M0 tumors (P = 0.028). Assessment of tumor microvasculature is therefore probably one of the most important prognostic predictors in renal cell carcinoma.