Does the Visibility of Grade Group 1 Prostate Cancer on Baseline Multiparametric Magnetic Resonance Imaging Impact Clinical Outcomes?

To assess whether the visibility of grade group (GG)1 prostate cancer (PCa) on baseline multiparametric magnetic resonance imaging (mpMRI) affects clinical outcomes.

We evaluated 454 men who underwent mpMRI between 2006 and 2018 with maximum GG1 PCa inclusive of MRI-targeted biopsy. MpMRIs were graded as negative, equivocal, or positive. Assessed outcomes were treatment-free survival (TFS), biopsy upgrade-free survival (UFS) and unfavorable disease at radical prostatectomy (RP) (pT≥3 and/or GG≥3). Kaplan-Meier and multivariable Cox proportional hazard analysis were used to estimate the impact of mpMRI and clinicopathologic variables (age, year, PSA density and measures of tumor volume on biopsy) on outcomes.

During follow-up (median 45.2 months), 61 men were upgraded on follow-up biopsy and 139 men underwent definitive treatment. In men with negative, equivocal and positive baseline mpMRIs, at 5-years, TFS was 79%, 73% and 49% (p<0.0001), UFS was 89%, 82% and 70% (p=0.002) and survival without unfavorable disease at RP was 98%, 98%, and 86% (p=0.007), respectively. At multivariable analysis both positive (hazard ratio [HR] 1.93, 95% CI, 1.21-3.09; p=0.006) and equivocal mpMRI (HR 2.02, 95% CI, 1.11-3.68; p=0.02) were associated with shorter TFS, and positive mpMRI was a significant prognostic factor for UFS (HR 2.03, 95% CI, 1.06-3.86; p=0.03) and unfavorable disease at RP (HR 4.45, 95% CI, 1.39-18.17; p=0.01).

Men with a positive mpMRI and GG1 PCa on MRI-targeted biopsy are at increased risk of intervention, upgrading, and unfavorable disease at RP compared to those with mpMRI-invisible GG1 PCa.

The Journal of urology. 2020 Jun 04 [Epub ahead of print]

Dominik Deniffel, Emmanuel Salinas, Marc Ientilucci, Andrew J Evans, Neil Fleshner, Sangeet Ghai, Robert Hamilton, Alexander Roberts, Ants Toi, Theodorus van der Kwast, Alexandre Zlotta, Antonio Finelli, Masoom A Haider, Nathan Perlis

Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, Canada., Division of Urology, Department of Surgical Oncology, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada., Department of Pathology, Laboratory Medicine Program, University Health Network, Toronto, Ontario, Canada., Joint Department of Medical Imaging, University Health Network/Sinai Health System, University of Toronto, Toronto, Ontario, Canada.