INTRODUCTION AND OBJECTIVE:
MRI to ultrasound fusion-targeted prostate biopsy (MRF-TB) has led to improved detection of clinically significant prostate cancer (csPCa) and reduced detection of indolent (GGG1) PCa. Though MRF-TB has improved diagnostic accuracy, there remains discordance between GGG on biopsy and radical prostatectomy (RP). We evaluated rates of discordance between MRF-TB, systematic biopsy, and RP, and evaluated clinical factors for prediction of discordance.
We identified a cohort of 535 men who underwent RP following a combined MRF-TB and SB, between 7/2013 and 8/2020, from an IRB-approved prospectively enrolled database. Men were included regardless of previous biopsy status or if they had been on active surveillance for PCa prior to the final biopsy preceding RP. The rate of PCa, csPCa (GGG≥2), upgrading and downgrading at time of RP, were compared between SB and MRF-TB. Univariate and multivariate analysis were utilized to determine pre-surgical variables predictive of upgrading at RP.
Pathologic results at time of RP are shown in Table 1. Biopsy upgrade at RP was observed in 30.2% overall, 22.2% when considering MRF-TB alone, and 42.5% on SB alone (MRF-TB alone versus SB alone p<0.0001). 11.6% of men with GGG≥2 on MRF-TB had upgrade on RP. Downgrade of MRF-TB was observed in 17.6% compared to 18.7% for SB (p=0.1). Baseline characteristics of men with any cancer on MRF-TB, included in multivariate analysis, is presented in Table 2. Of variables tested, only a dominant PIRADS 3 lesion was predictive of upgrade (OR 0.163; 95%CI 0.0299-0.888; p=0.038).
Pathologic upgrade at time of RP is reduced on MRF-TB as compared to SB, but still occurs in approximately 1/5 of men. csPCa on MRF-TB further reduces the likelihood of upgrade. PI-RADS score is additionally predictive of the likelihood of upgrade.
Source of Funding:
Joseph and Diane Steinberg Charitable Trust