LAUSR

59Background: Pathologic progression is identified in > 25% of prostate cancer (CaP) patients on active surveillance (AS). Yet, identifying patients at risk for progression is limited to PSA based biomarkers with variable utility. Multiparametric MRI (mpMRI) with fusion-guided prostate biopsy (FBx) has shown utility in risk stratification for patients considering AS. We compared mpMRI characteristics with PSA kinetics for the prediction of pathologic progression in AS patients. Methods: A review of men on AS with serial mpMRI and 2 or more FBx sessions was performed. FBx sessions consisted of targeted biopsies and a 12 core systematic biopsy. Men who met NIH Expanded AS criteria included those with low and intermediate risk CaP, Gleason score ≤ 3+4 = 7 with no restriction on percent core involvement or number of cores positive. Progression was defined by patients with initial Gleason 3+3 = 6 to any Gleason 4, and Gleason 3+4 = 7 to a primary Gleason 4 or higher. MRI progression was defined as increase in ...