Relationship of Chronic Histologic Prostatic Inflammation in Biopsy Specimens With Serum Isoform [-2]proPSA (p2PSA), %p2PSA, and Prostate Health Index in Men With a Total Prostate-specific Antigen of 4-10 ng/mL and Normal Digital Rectal Examination

OBJECTIVE To investigate the relationship between serum [-2] proPSA (p2PSA) and derivatives with chronic histologic prostatic inflammation (CHPI) in men undergoing prostate biopsy for suspected prostate cancer (PCa). METHODS This nested case-control study resulted from an observational prospective trial for the definition of sensibility, specificity, and accuracy of p2PSA, %p2PSA, and Beckman Coulter Prostate Health Index (PHI), in men undergoing prostate biopsy, with a total prostate-specific antigen (PSA) of 4-10 ng/mL and normal digital rectal examination. CHPI was the outcome of interest and defined as the presence of moderate to large infiltration of lymphomononuclear cells with interstitial and/or glandular disruption in absence of PCa. p2PSA, %p2PSA, and PHI were considered the index tests and compared with the established biomarker reference standard tests: tPSA, fPSA, %fPSA. RESULTS Of 267 patients subjected to prostate biopsy, 73 (27.3%) patients were diagnosed with CHPI. Comparing CHPI with PCa patients, %p2PSA and PHI were found to be significantly lower, whereas fPSA and %fPSA were significantly higher. %p2PSA and PHI were the most accurate predictors of CHPI at biopsy, significantly outperforming tPSA, fPSA, and %fPSA. On the contrary, no significant differences were found in PSA, p2PSA, and derivatives between CHPI and benign prostatic hyperplasia (BPH) patients. CONCLUSION Our findings showed that p2PSA, %p2PSA, and PHI values might discriminate PCa from CHPI or BPH, but not CHPI from BPH, in men with a total PSA 4-10 ng/mL and normal digital rectal examination. p2PSA isoform and its derivatives could be useful in clinical decision making to avoid unnecessary biopsies in patients with CHPI and elevated tPSA value. UROLOGY 83: 606-612, 2014. (C) 2014 Elsevier Inc.