638 - Diagnostic performance of multiparametric MRI in prostate cancer: Per core analysis of three prospective ultrasound/MRI fusion biopsy datasets

Abstract

Clinicopathologic parameters of the anterior index tumor and other tumor foci were assessed and compared to non-APC in the same cohort. Previous biopsy information was correlated with RP. RESULTS: Of the 467 patients in this cohort, 72 (15%) had APC: 50 in the anterior peripheral zone (APZ, 69%); 10 in the transitional zone (TZ, 14%); and 12 involving both the APZ and TZ (17%). 25 APC were single tumors (35%), and the rest were multifocal. Clinicopathologic information was available for 72 APC patients and 308 non-APC patients and is compared in Table 1. 15% of APC patients demonstrated a primary Gleason pattern 4 or higher, and 21% had extraprostatic extension (EPE) present. None of the APC, including the high-grade (GS>7) cases, demonstrated seminal vesicle invasion (SVI). 10 APC had a positive surgical margin (13%), most commonly at the apex or base. 56 APCwere preceded by an extended biopsy (78%), while 2 APC had only sextant biopsy (3%) and 14 APC were identified after a combination of extended and perineal saturation biopsies (19%). APC was present on significantly fewer cores and with less tumor involvement of the core. APC patients frequently (54%) had a higher GS or novel Gleason pattern 5 at RP than at biopsy. Distribution of preoperative serum PSA levels was similar between APC and non-APC patients. CONCLUSIONS: APC demonstrate distinct clinicopathologic features (including absence of SVI) and are frequently under-graded and minimally sampled at the time of biopsy. These unique characteristics may have a clinical impact on detection (i.e., need for saturation biopsy) and suitability for inclusion in active surveillance protocols. Future longterm studies are needed to determine the outcome of patients with APC.