SUO 2017: Should Patients With Negative Multi-parametric MRI Avoid Prostate Biopsy?

Washington, DC ( Introduction: This study attempted to evaluate the detection rate and predictors of clinically significant prostate cancer (CSPCa) in patients with negative multi-parametric magnetic resonance imaging (mpMRI) prior to prostate biopsy (PBx).

Methods: The authors identified patients from an institutional board-approved database of 1500 patients. Inclusion criteria included a negative mpMRI (3T; DWI, T2W, DCE), prior to 12-core systematic PBx. Exclusion criteria included prior treatment for PCa and mpMRI performed not at the authors’ center. Negative mpMRI was defined as Prostate Imaging-Reporting and Data
System version 2 (PIRADS) score < 3. CSPCa was defined as Gleason score > 6 on PBx. mpMRIs and PBx were reviewed by an experienced uroradiologist and uropathologist, respectively.

Results: A total of 135 patients met inclusion/exclusion criteria. The median (IQR) age, PSA, prostate volume and PSA density (PSAD) were: 64 years (58-69), 5.9ng/mL (4.1-8.0), 55cc (38-79), and 0.1 ng/ml/cc (0.07-0.15), respectively. Of the patients, 48 (36%) were PBx-naive, 60 (44%) had previous negative PBx, and 27 (20%) had previous positive PBx, of those, 20 (15%)
patients were on active surveillance. The PCa (any Gleason) and CSPCa detection rate were 37.8% (51/135) and 17.0% (24/135), corresponding to a negative predictive value (NPV) of 62.2% and 83%, respectively. Patients detected with CSPCa (N=24) had smaller prostate (p=0.00036), higher PSAD (p<0.0001) and previous positive PBx (p=0.025) when compared to non-CSPCa group (N=111). Multivariable analyses showed PSAD > 0.15ng/ml/cc as an independent predictor for detection of CSPCa (p<0.01).

Conclusion: Patients with high PSA density should consider prostate biopsy even if mpMRI is negative. Prostate cancer, Gleason > 7, can be detected in 17% of the patients with negative mpMRI undergoing systematic 12-core biopsy. The authors demonstrated that PSA density > 0.15 ng/ml/cc is an independent predictor of CSPCa on biopsy. The NPV of mpMRI for clinically significant prostate cancer is 83%.

Presented by: Masakatsu Oishi, USC institue of urology, Los-Angeles, CA, USA

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre, @GoldbergHanan, at the 18th Annual Meeting of the Society of Urologic Oncology, November 29-December 1, 2017 – Washington, DC