Serum testosterone improves the accuracy of Prostate Health Index for the detection of prostate cancer

• Published in: Clinical biochemistry 2014-07, Vol.47 (10-11), p.916-920
• Main Authors: Friedersdorff, Frank, Manus, Philipp, Miller, Kurt, Lein, Michael, Jung, Klaus, Stephan, Carsten
• Format: Article
• Language: English
• Subjects: Aged; Biopsy; Diagnosis; Humans; Kallikreins - blood; Male; Middle Aged; Prostate - metabolism; Prostate - pathology; Prostate cancer; Prostate Health Index; Prostate-Specific Antigen - blood; Prostatic Neoplasms - blood; Prostatic Neoplasms - pathology; Testosterone; Testosterone - blood
• ISSN: 0009-9120; 1873-2933
• DOI: 10.1016/j.clinbiochem.2014.02.002

Prostate cancer (PCa) detection suffers from low specificity when using the prostate-specific antigen (PSA) alone. The aim of this study was to investigate the applicability of total testosterone (tT), free testosterone (fT), the fraction (%) of fT to tT (%fT), and bioavailable testosterone (bioT) in serum to improve the diagnostic validity of the serum (−2)pro-PSA-based Prostate Health Index (PHI). Total and free PSA (tPSA, fPSA), (−2)pro-PSA, testosterone, and sex-hormone-binding globulin were measured by automated immunoassays from serum of 193 men scheduled for prostate biopsy (99 PCa, 94 without PCa). fT and bioT were calculated using an online calculator. Statistical analyses were performed by non-parametric tests (Wilcoxon signed rank, Mann–Whitney, Kruskal–Wallis), binary logistic regression, and receiver operating characteristic (ROC) analyses. Compared with the non-malignant controls, PCa patients had significantly higher tPSA concentrations and PHI values, but lower %fPSA values and lower concentrations of tT, fT, and bioT. PCa could be differentiated from controls by PHI, tT, fT, bioT, and %fPSA. PHI showed the largest area under the ROC curve (AUC=0.73) that was increased further by the inclusion of bioT or tT in a binary logistic regression model. The AUC of PHI in patients with tT concentrations of