A Study on the Tumor Angiogenesis and Expression of Cytokine and Growth Factors in the Prostatic Carcinoma

ABSTRACT

There is considerable experimental evidence to indicate that tumor growth is dependent on angiogenesis. However, we do not understand how the angiogenic activity is initiated by a given tumor. There is a clear distinction between a stage without neovascularization, which correlates with a paucity of metastases, and a stage in which increasing neovascularization correlates with a rising rate of metastasis. The authors therefore asked whether the extent of angiogenesis in human prostatic carcinoma is correlated with the tumor grades or some growth factors. To investigate how tumor angiogenesis correlates with tumor aggressiveness, the authors counted microvessels within the various grades of invasive prostatic carcinomas of 44 patients and the nodular hyperplasias of 10 patients. Highlighting of the vessels by immunohistochemical staining for factor VIII-related antigen and assessment of the tumor aggressiveness by the degree of expression of some growth factors(transforming growth factor-alpha, and beta, epidermal growth factor), tumor necrosis factor-alpha and tumor grading(Gleason's score) were done. As a result, both microvessel counts and the expression of growth factors and tumor necrosis factor correlated with tumor grades. In conclusion, the number of microvessels per 200 X fields in the areas of most intense neovascularization in a prostatic carcinoma may be a predictor of the patient's prognosis. Therefore, assessment of tumor angiogenesis may prove valuable in selecting patients with prostatic carcinoma, especially small needle biopsy, for aggressive therapy.