Prostate Active Surveillance Study

Inclusion Criteria: * Histologically confirmed adenocarcinoma of the prostate from a prostate biopsy. * Clinically localized prostate cancer: T1-2, NX or N0, MX or M0. * No previous treatment for prostate cancer (including hormonal therapy, radiation therapy, surgery, or chemotherapy). * ECOG Performance Status 0 or 1. * Patient has elected Active Surveillance as preferred management plan for prostate cancer. * Patient consent has been obtained according to local Institutional Review Board for acquisition of research specimens. * Patient is accessible and compliant for follow-up. * Prostate cancer diagnosis cannot be more than 3 years prior to baseline visit date. * No more than two prostate biopsies including the initial biopsy in which cancer was diagnosed. * If cancer diagnosis is more than one year before enrollment, there must be two prostate biopsies including the initial biopsy in which cancer was diagnosed and a subsequent biopsy. The subsequent biopsy may occur on the same day as the baseline visit. * Biopsies must have at least 10 cores. Exclusion Criteria: * Unwillingness or inability to undergo serial prostate biopsy. * History of other malignancies, except: adequately treated non-melanoma skin cancer or adequately treated superficial bladder cancer (Ta) or other solid tumors curatively treated with no evidence of disease for \> 5 years.