Provided is a method for evaluating test agents as candidates for treating prostatic diseases, including benign prostatic hyperplasia and androgen dependent and androgen independent prostate cancer. The method comprises providing a mouse comprising a human prostate primary xenograft, where the xenograft contains blood vessels that include human endothelial cells, initiating androgen deprivation in the mouse, administering to the mouse a test agent within a period of 1-7 days after initiating the androgen deprivation, and determining a reduction in human epithelial cells in the xenografts and/or a reduction in number of the endothelial cells or blood vessels in the xenograft. Also provided is a method for treating an individual for human prostate cancer or benign prostatic hyperplasia. The method comprises initiating androgen deprivation in the individual and administering to the individual an agent capable of inducing apoptosis of vascular endothelial cells within a period of 1-7 days of initiating androgen deprivation.