Advances in angiogenesis research: Relevance to urological oncology

Purpose: Important advances in angiogenesis research are reviewed along with recent data implicating angiogenesis in the pathogenesis of urological malignancies. Materials and Methods: The current understanding of angiogenesis and its importance in tumor biology is summarized. The rationale for anti-angiogenic therapy is reviewed and the clinical experience with these agents is discussed. An extensive literature search of angiogenesis in urological malignancies was performed. Results: Quantitative immunohistochemistry for endothelial antigens suggests that, as is the case with many other tumors, induction of angiogenesis contributes to the malignant phenotype of prostate and bladder carcinomas. Anti-angiogenic agents have demonstrated efficacy against urological tumors in experimental systems, and recent data suggest that these agents may also be useful for chemoprophylactic purposes. Putative angiogenesis inducers specific for each of the major urological malignancies have been identified. Quantitation of the expression of angiogenesis inducers and estimation of microvessel density have demonstrated prognostic value for urological malignancies. Conclusions: The available data indicate that angiogenesis has an important role in the progression and metastasis of urological malignancies. Preclinical data coupled with experience in other cancers indicate that combining anti-angiogenic therapy with conventional treatment modalities has the potential to improve dramatically our management of these malignancies. Further research will be needed to define the mechanisms controlling angiogenesis in urological malignancies and to determine if any of the angiogenic correlates will be of genuine clinical use. The rapid pace of research in this field suggests that this aspect of tumor biology will soon have an increasingly important role in the evaluation and treatment of urological cancers.