Validation of the Decipher prostate cancer classifier in intermediate to high-risk men treated with radical prostatectomy but without additional therapy upon PSA rise.

173 Background: Radical prostatectomy (RP) is a primary treatment option for men with intermediate and high risk prostate cancer. Though many will be effectively cured with local therapy alone, these men are by definition at higher risk of adverse pathologic findings and clinical disease recurrence. The Decipher test has been previously shown to predict metastatic progression in cohorts that included adjuvant and salvage therapy after RP. Here we evaluate Decipher in a natural history cohort of at risk men who received no additional treatment until the time of metastatic progression. Methods: Men with NCCN intermediate or high risk localized prostate cancer treated with RP at the Johns Hopkins Medical Institute (1992-2010) with at least 5 years of post-operative follow up were identified. Only men with initial undetectable PSA after surgery and who received no therapy prior to metastasis detection were included (n=765). A case-cohort design was used to randomly sample the cohort. The highest Gleason grade...