This trial will evaluate whether the following aspect of surgical technique influence outcome: Lymph node dissection. In some patients, scans taken before surgery show that a lymph node has cancer. Surgeons make sure to remove those affect lymph nodes and all other lymph nodes in the area. However, it is not known whether removing lymph nodes helps prostate cancer patients whose scans do not show positive nodes. In this study, patients with clear scans will either receive a lymph node dissection or not.