PD55-03 THE ROLE OF MRI AND FUSION BIOPSY IN THE INITIAL DIAGNOSIS AND FOLLOW-UP OF PATIENTS UNDERGOING ACTIVE SURVEILLANCE OF PROSTATE CANCER

Abstract

INTRODUCTION AND OBJECTIVES: Active Surveillance (AS) is increasingly utilized to manage very-low (VLR), low (LR), and some favorable intermediate risk (IR) prostate cancer (PCa). Most studies examining AS outcomes have been based on standard 12-core systematic biopsies (SB). We examined the outcomes of patients who were selected for AS after undergoing multi-parametric magnetic resonance imaging (mpMRI) with fusion guided biopsies (FB) of MRI-detected lesions in addition to SB. METHODS: A retrospective review was conducted of all patients with Gleason Grade Group (GG) 1 (Gleason Score 3+3) or 2 (Gleason Score 3+4) PCa managed initially with AS. Kaplan-Meier graphs were constructed to determine the time patients continued AS and time for GG progression free-survival (PFS). Cox proportions hazard regression was performed to determine factors significant for GG progression. Those who underwent radical prostatectomy had their final pathology examined for adverse pathology (GG>2 or >T3 disease) RESULTS: 246 (172 GG 1 and 74 GG 2) patients met inclusion criteria. The median time remaining on AS for the GG 1 group was not reached (although nearing 96 months) and for the GG 2 group was 53.88 months, p<0.01. Median time for GG PFS for the GG 1 and GG 2 groups were 57.27 and 45.11 months, respectively, p = 0.03. Significant variables for progression included age (HR 1.05 95% CI 1.01-1.09, p<0.01), PSA density (HR 1.03 95% CI 1.01-1.09, p = 0.01, size of the largest lesion on mpMRI (HR 1.66 95% CI 1.07-2.57, p = 0.02) and the number of targeted biopsy cores positive for cancer (HR 1.24 95% CI 1.03-1.50, p = 0.02). None of the AS patients who went on to RP had positive margins or lymph nodes. AP occurred in 3/18 (16.7%) of patients starting with GG 2 disease. CONCLUSIONS: mpMRI-directed FB provides an effective way to select and monitor patients with LR PCa on AS. This additional information helps in predicting which patients will progress on AS.