Scott Eggener

Purpose: This study investigates whether quantitative MRI and histology of the prostate reveal differences between races, specifically African Americans (AAs) and Caucasian Americans (CAs), that can affect diagnosis. Materials and Methods: Patients (98 CAs, 47 AAs) with known or suspected prostate cancer (PCa) underwent 3T MRI (T2W, DWI, and DCE-MRI) prior to biopsy or prostatectomy. Quantitative mpMRI metrics: ADC, T2, and DCE empirical mathematical model parameters were calculated. Results: AAs had a greater percentage of higher Gleason-grade lesions compared to CAs. There were no significant differences in the quantitative ADC and T2 values between AAs and CAs. The cancer signal enhancement rate (α) on DCE-MRI was significantly higher for AAs compared to CAs (AAs: 13.3 ± 9.3 vs. CAs: 6.1 ± 4.7 s⁻¹, p < 0.001). The DCE signal washout rate (β) was significantly lower in benign tissue of AAs (AAs: 0.01 ± 0.09 s⁻¹ vs. CAs: 0.07 ± 0.07 s⁻¹, p < 0.001) and significantly elevated in cancer tissue in AAs (AAs: 0.12 ± 0.07 s⁻¹ vs. CAs: 0.07 ± 0.08 s⁻¹, p = 0.02). DCE significantly improves the differentiation of PCa from benign in AAs (α: 52%, β: 62% more effective in AAs compared to CAs). Histologic analysis showed cancers have a greater proportion (p = 0.04) of epithelium (50.9 ± 12.3 vs. 44.7 ± 12.8%) and lower lumen (10.5 ± 6.9 vs. 16.2 ± 6.8%) in CAs compared to AAs. Conclusions: This study shows that AAs have different quantitative DCE-MRI values for benign prostate and prostate cancer and different histologic makeup in PCa compared to CAs. Quantitative DCE-MRI can significantly improve the performance of MRI for PCa diagnosis in African Americans but is much less effective for Caucasian Americans.

This study investigated whether quantitative MRI and histology of the prostate reveals differences between races that can affect diagnosis. Cancer signal enhancement rate (α) on DCE-MRI was significantly higher for African Americans (AA) compared to Caucasian Americans (CA). Signal washout rate (β) was significantly lower in benign tissue in AAs and significantly elevated in cancers in AAs. However, no significant differences were found for ADC and T2. ROC analysis showed that ADC and T2 are slightly less effective in AA compared to CA. DCE significantly improves the differentiation of PCa from benign in AAs (α: 52%, β: 62% more effective in AA compared to CA). Histologic analysis showed cancers have a greater proportion of epithelium and lower lumen in AA compared to CA. This study shows that the different races have different quantitative MRI values and histologic makeup. Quantitative DCE-MRI is highly effective and improves PCa diagnosis in African Americans.

Serum prostate-specific antigen (PSA) testing is a cornerstone of the diagnosis and management of prostate cancer (PCa), but its poor specificity is a significant limitation to its utility as a screening test. This issue has led to an ongoing search for screening biomarkers that can be used in men without a diagnosis of PCa. One such marker is free PSA, which is the fraction of PSA in the serum unbound to proteins. Free PSA is divided by total PSA to calculate the percentage of free PSA (%fPSA), which is a well-studied biomarker with an inverse relationship to the risk of PCa. Head to head, %fPSA outperforms total PSA in detecting any PCa and grade group 2 or higher PCa.^1,2 Percent-free PSA is widely used in the work-up for PCa on its own or as a component of composite tests such as The 4Kscore Test or Prostate Health Index. To aid with interpretation, laboratories often report %fPSA results with a standardized table that provides estimates for risk of biopsy-detected PCa based on %fPSA. Although the estimates provided vary by institution, they generally describe %fPSA less than 10% as higher risk and %fPSA above 25% as lower risk. At many institutions, including ours, for men with PSA values between 4 and 10 ng/mL, the reported risk of PCa if %fPSA is less than 10% is greater than 40%, whereas in those with %fPSA above 25%, it is less than 10% Figure 1.