<qa>  What is the purpose of this study?The purpose of this study is to see if the protein pattern in your blood can predict whether or not your prostate tumor is aggressive. We will use a new and very sensitive technique, called mass spectroscopy, to measure hundreds of pieces of protein in your blood. A computer will make a picture of the protein pattern. We will do this in 500 men before their prostate surgery and see if there is a pattern that predicts what the tumor looks like under the microscope. We will also check the protein pattern in your blood 6 weeks to 12 months after the surgery to see if your pattern changes. 