Multiparametric Magnetic Resonance Imaging of the Prostate to Assess Disease Progression and Genomics in Patients Undergoing Active Surveillance for Prostate Cancer

Background: * Active Surveillance (AS) is a standard approach in the treatment of low and intermediate risk prostate cancer which employs a strategy of monitoring the clinical progression of prostate cancer. * AS utilizes prostate biopsies, prostate specific antigen (PSA), and digital rectal examinations (DRE) as tools to determine clinical progression in prostate cance * This protocol aims to assess an additional tool, multiparametric magnetic resonance imaging (mpMRI) to actively visualize and monitor disease within the prostate in addition to standard instruments used to determine clinical progression of disease. Objectives: * To determine the role of mpMRI in the selection and management of participants for AS by correlating imaging findings with pathological progression as determined on serial biopsies. * To determine the optimal interval of MR imaging in monitoring AS participants for evidence of progression by correlating sequential MRIs with biopsies with the goal to reduce unnecessary imaging. * To evaluate the relationship between mpMRI, prostate biopsy pathology results, and progression in AS participants to determine if prostate biopsies may be safely avoided based on the accuracy of imaging (sensitivity and specificity). Eligibility: * Men, 18 years and older with biopsy confirmed prostate cancer * Gleason Score which less than or equal to 3+4=7 * Initial diagnosis of prostate cancer within 2 years of study entry * Capable of being consented to the protocol Design: * Single arm, prospective, cohort study to correlate mpMRI with prostate biopsy pathology. * We plan to accrue 508 participants over the entire study period, assuming about a 10% dropout to allow adequate statistical review. * Participants will be monitored for clinical progression of their prostate cancer with PSA, DRE, mpMRI, and prostate biopsy (systematic and MRI lesion targeted) as follows: * Initial prostate cancer antigen (PSA) screening with an additional PSA screen every 12 months * Initial DRE screening with additional DRE to be performed every year that either prostate MRI or biopsy is performed * Initial mpMRI and prior to each biopsy (i.e., mandated at least every two years until year five, and then every three years thereafter) * Initial systematic 12-Core prostate biopsy and MRI guided fusion (MRI-US fusion) prostate biopsy of all suspicious lesions (i.e., targeted biopsy). Future biopsies, including 12-core systematic and targeted biopsy (to be performed in the same session) will then be mandated every two years until year five at which time biopsies will be performed every three years thereafter unless contraindicated. * mpMRI and biopsies may be performed earlier if clinically indicated and will revert back to previous mpMRI/biopsy schedule after. * Biopsy pathology results will be used as the standard for diagnosis of clinical progression.