2223 MEN CONSIDERING ACTIVE SURVEILLANCE FOR LOW VOLUME PROSTATE CANCER FOUND AT TRUSB DEMONSTRATE LARGER VOLUMES OF DISEASE THAN EXPECTED AT ADAPTED TRANSPERINEAL GUIDED TEMPLATE BIOPSY (ATSB)

Abstract

INTRODUCTION AND OBJECTIVES: With increasing sensitivity of detection a significant proportion of men are diagnosed with minimal volume prostate cancer (MVPCa). The false negative rate associated with TRUSB is well documented; logic extends this unreliability to PCa volume prediction. To address this aTSB has been offered to all patients considering active surveillance with MVPCa, suitable for radical treatment who presented to one regional tumour network meeting from a non-screened population of 1 million over 4 years. METHODS: 46 patients who were found to have MVPCa at TRUSB underwent aTSB within 12 months of TRUSB. MVPCa was defined by 5% Gleason 7, 25% Gleason 6 and in all cases involving no more than 2cores at TRUSB. aTSB was performed using a brachytherapy template and implant probe, avoiding the periurethral area at the base. RESULTS: Median age was 64yrs(range 49-79), median PSA 8.1ng/ml(0.44-35), median prostate volume measured at aTSB 37cc(16-74) and PSAD 0.22(0.02-0.73), Median time from last TRUSB 106days(55-321). 9 had PSAD 0.15. Mean of 26 cores(15-37) was taken, resulting in mean of 0.7cores/cc(0.4-0.9). Upgrading occurred in 30/46 patients following aTSB(65%), with Gleason scores rising to 7,8,or 9 and mean aggregate cancer core length recorded at 13mm(0.4-121.3). The number of positive cores was 3 in 54%, median 4(1-13). aTSB was negative in 5 patients, two with a PSAD 0.15, one with an initially positive TRUS then subsequent negative result, all had a tiny focus of PCa at TRUSB and all but 1 had a benign MRI. 17 (37%), initially considering AS after TRUSB, subsequently selected radical treatments following aTSB. PSA, PSAD or %Free PSA did not provide reliable cut-off points for prediction of upstaging. CONCLUSIONS: This study confirms that TRUSB is not reliable in its prediction of mVPCa. In those considering active surveillance an aTSB is advocated. The aTSB result provides a more accurate estimate of cancer volume and distribution, informing on suitability for active surveillance or the most appropriate radical treatment.