Introduction:

The significance of PI-RADS 3 lesions remains an uncertainty in the screening and diagnosis of prostate cancer. For Black men, who experience disproportionately higher rates of mortality from prostate cancer, these indeterminate lesions may pose greater risk for harboring clinically significant prostate cancer, particularly as the PI-RADS scoring system was validated in a cohort predominately comprised of men of European descent. We hypothesized that MRI may be inappropriately calibrated in Black men and that PI-RADS 3 lesions in Black men may behave more similarly to PI-RADS 4 lesions (“high” risk lesions) in non-Black men.

Methods:

We conducted a secondary analysis of data from the PREVENT trial, a multi-institutional, randomized controlled trial with the primary endpoint of comparing infectious complications between transrectal and transperineal prostate biopsy. We identified trial participants who self-identified as Black men whose highest risk lesion was a PI-RADS 3 on MRI (“PI-RADS 3 Black” cohort) and compared them to non-Black men with a highest risk lesion of PI-RADS 4 (“PI-RADS 4 non-Black” cohort). On a per-prostate basis, we compared overall prostate cancer detection and clinically significant prostate cancer (csPCa) detection, defined as grade group (GG) 2 or higher, on biopsy using Fisher’s exact test and multivariable logistic regression.  

Results:

Among 755 men enrolled in the study, 108 (14%) self-identified as Black. The PI-RADS 3 Black cohort included 20 men compared to 269 men in the PI-RADS 4 non-Black cohort. Men in the PI-RADS 3 Black cohort were younger (median 61, IQR 57-64 vs median 66, IQR 61-71, P<0.01). Both groups had a similar PSA density (overall median 0.13, IQR 0.09-0.19, P=0.3). Both groups had similar rates of overall cancer detection (70% vs 70%, P=1), with a numerically higher, but statistically similar rate of csPCa for the PI-RADS 4 non-Black cohort (54% PI-RADS 4 non-Black vs 40% PI-RADS 3 Black, P=0.3) (Figure 1). In a multivariable logistic regression model adjusting for age and PSAD, there was no significant difference in cancer detection (OR: 1.03, 95%CI: 0.84-1.27, P=0.8) or csPCa detection (OR: 0.92, 95%CI: 0.74-1.16, P=0.5) between PI-RADS 3 Black and PI-RADS 4 non-Black cohorts.  

Conclusion:

Among a large, multi-institutional study of patients, Black men with PI-RADS 3 lesions on MRI had comparable rates of cancer and csPCa detection on biopsy when compared to non-Black men with PI-RADS 4 lesions. These findings suggest there may be a systematic issue with the calibration of prostate MRI, which may not account for the higher prevalence of prostate cancer in Black men. 

Funding: This work was supported by the NCI (5R01CA241758)