Predictive Value of PIRADS v2 for Any and Clinically Significant Prostate Cancer on Prostate Biopsy in a High Risk Ethnic Cohort
African Americans (AA) typically harbor more aggressive prostate cancer (PCa). Prostate Imaging Reporting and Data System version 2 (PIRADS v2) for prostate multiparametric magnetic resonance imaging (mpMRI) interpretation is increasingly utilized to guide PCa screening. We assessed the predictive value of PIRADS v2 for any PCa on corresponding prostate biopsy, stratified by patient ethnicity, at our institution.
All PIRADS v2 reports of mpMRI studies performed from 1/1/2015 to 7/1/2017 for evaluation of PCa were reviewed. Each patient's age, ethnicity, body mass index (BMI), prostate biopsy results, and prostate specific antigen (PSA) were extracted. Results were analyzed based on ethnicity - AA vs non-AA. Demographics were compared by t-test, and the relationship between PIRADS lesions 3-5 and pathologic outcomes - any cancer, or clinically significant (CS) cancer on biopsy, defined as Gleason > 7 - were analyzed using multivariable logistic regression.
We reviewed 557 prostate MRIs; 206 (37.0%) AA, 351 (63.0%) non-AA. There was no difference in age (p=0.864), BMI, (p=0.590), or pre-biopsy PSA (p=0.250) between the two groups. 48% of AAs with a PIRADS 3 lesion had CS PCa anywhere in the prostate compared to 25% (22/75) of non-AAs (p=0.003) on bivariate analysis (Table 1). There was no significant difference between groups for PIRADS 4 or 5 lesions. Age (OR=1.03, CI: 1.003-1.050) and BMI (OR=0.96, CI: 0.93-0.99) were independent predictors of CS PCa on univariate analysis. Adjusting for both, AAs with a PIRADS 3 lesion had 3.1 times higher odds of having CS PCa anywhere in the prostate compared to non-AAs with a PIRADS 3 lesion (OR=3.1, CI: 1.61-5.81). Multivariate analysis adjusting for PIRADS revealed that AAs with PIRADS 3-5 lesions were 53% more likely than non-AAs to have an overall positive biopsy result anywhere in the prostate (OR=1.53, CI: 1.02-2.28).
Compared to non-AAs, AAs with any PIRADS 3-5 lesion on prostate MRI were significantly more likely to harbor any cancer on biopsy, and with a PIRADS 3 lesion were 3.1 times more likely to harbor CS PCa. Our results indicate that among AAs, the presence of a PIRADS 3-5 lesion on pre-biopsy MRI may warrant more aggressive screening or counseling regarding the need for a prostate biopsy compared to non-AAs.