Ces Urol 2014, 18(1):21-25 | DOI: 10.48095/cccu2014003

Benefit of determining [-2]proPSA levels in the differential diagnosis of prostate cancer

Radka Fuchsová¹, Ondřej Topolčan¹, Jindra Vrzalova¹, Milan Hora², Olga Dolejšová², Jiří Klečka³, Petr Kasík¹

¹ Laboratoř imunodiagnostiky a Centrální izotopová laboratoř LF, Plzeň

² Urologická klinika FN a LF UK, Plzeň

³ Soukromá urologická praxe, Plzeň

Aim:
The goal of this study was to examine if determining [-2]proPSA levels and calculating the Prostate Health Index (PHI) could improve overall sensitivity and specificity of this marker in the diagnosis of prostate cancer compared to standard markers (PSA and %freePSA), and propose an optimal PHI cut-off.

Methods:
A group of 76 patients with suspected prostate cancer, who were scheduled to undergo prostate biopsies, was tested to determine the total PSA, freePSA and [-2]proPSA levels, calculated %freePSA and Prostate Health Index (PHI). Biomarkers were determined using chemiluminescent technology on a Dxl 800 (Beckman Coulter, USA). Statistical analysis was performed using SAS version 9.2.

Results:
We found a statistically significant improvement in the area under the ROC (AUC) for both [-2]proPSA (0.77) and especially for PHI (0.88) levels compared with total PSA (0.59) and % freePSA (0.61) levels. None of the patients included in this study, with histological diagnosis of prostate cancer on biopsy, had a PHI level under 40.

Conclusion:
Determining the [-2]proPSA and derived PHI values contributes significantly to accuracy in the process of the differential diagnosis between BPH and prostate cancer. Based on out experience, a PHI cut-off of 40, with a gray area between 30 and 40, is optimal for use in routine clinical practice.

Keywords: benign prostatic hyperplasia, prostate cancer, marker, PHI, [-2]proPSA

Received: November 20, 2013; Accepted: January 20, 2014; Published: January 1, 2014