Utility of PCA3 and TMPRSS2: ERG urinary biomarkers to predict pathologic outcomes in African American men undergoing radical prostatectomy.

Abstract

e547 Background: Tremendous disparity exists between preoperative characteristics and pathologic outcomes in men electing radical prostatectomy (RP) for localized prostate cancer (PCa). We sought to determine the performance characteristics of urinary PCA3 andTMPRSS2:ERG (T2:ERG) to predict pathologic outcomes in a racially diverse group of men undergoing RP. Methods: Following IRB approval, post digital rectal exam (DRE) urine was prospectively collected in consecutive patients with known PCa prior to RP. PCA3 and T2:ERG RNA copies were quantified and normalized to PSA mRNA copies using the Progensa assay (Hologic, San Diego, CA). Nonparametric Mann-Whitney U tests were performed to determine the ability of PCA3 and T2:ERG to predict higher risk PCa and notable disease features. Results: The cohort consisted of 214 men with PCa who underwent RP, and 89 men (42%) were African American (AA). The men in the cohort generally had higher risk disease, with 75% having AUA risk stratification of intermediate/high-risk PCa. PCA3 discriminated between biopsy low- and intermediate/high-grade Gleason Score (p = .005) and pathologic low- and intermediate/high-grade Gleason Score (p = 0.001). For men with low-risk PCa, PCA3 also predicted Gleason Score upgrading from biopsy to prostatectomy specimen (p = 0.003). PCA3 could not predict the presence of perineural invasion, lymph node positivity, seminal vesical invasion, positive surgical margins or extraprostatic extension. When stratified by race, within the AA cohort, T2:ERG did predict upgrading from Gleason 6 disease at the time of biopsy to higher grade pathology at RP (p = 0.016). However, T2:ERG was not predictive for the overall cohort, nor was it predictive for any of the disease features found to be significant with PCA3. Conclusions: In a racially-diverse group of men undergoing RP, PCA3 and T2:ERG urinary assays have limited ability to characterize aggressive pathologic features at the time of RP regardless of race.