259 Serum isoform [-2]proPSA (p2PSA) and its derivates, %p2PSA and PHI (prostate health index), are more accurate than the reference standard test (PSA) in men scheduled for repeat biopsy

Abstract

Aim In men with a negative first biopsy but persistent suspicion of PCa, the AUA and EAU recommend to repeat a biopsy. Repeat biopsies are negative in approximately 80% of men and they may be associated with economic costs, anxiety, discomfort, and sometime severe complications. The aim of this study was to determine the performance characteristics and clinical utility of the isoform [-2]proPSA and its derivates in detecting PCa in men scheduled for repeat biopsy . Material & Methods: This study was an observational prospective evaluation of a cohort of men with one or two previous negative prostate biopsies, with persistent suspicion of PCa (suspected DRE, elevated tPSA and or low %fPSA) who were scheduled for repeat biopsy. Men receiving medical therapy known to affect serum PSA (dutasteride and finasteride), suffering from prostatitis and having had invasive treatment for benign prostatic hyperplasia (BPH), such as TURP or HoLEP, were excluded. The primary endpoint was to determine the diagnostic accuracy of %p2PSA ⎨[(p2PSA pg/mL)/(fPSA ng/ml x 1000)]x100⎬ and Beckman-Coulter PHI [(p2PSA/fPSA) x √tPSA)] (index tests), and to compare it with the accuracy of established PCa serum tests (tPSA, fPSA and %fPSA) (reference standard tests). Multivariable logistic regression models, fitted for the prediction of the presence of PCa, were complemented by predictive accuracy analysis (ROC curves). All the patients underwent ambulatory repeated TRUS-guided prostate biopsies (18-22 cores). .