The objective of this study was to evaluate total testosterone (tT) as a diagnostic tool for CaP, using a large sample of patients with increased risk for CaP and including different prostate histopathologies. The study included a total of 1,577 consecutive patients referred for ultrasound guided trans-rectal prostate biopsy (median tPSA: 7.0ng/mL), in whom tT, tPSA, and free PSA (fPSA) were measured in fasting blood samples collected before biopsy. The association between continuous variables was calculated. The diagnostic capability of the different biomarkers was evaluated with receiver operating characteristic (ROC) analysis. Analyses were repeated using only patients with tPSA <4ng/mL.
Prostatic biopsies revealed CaP in 620 cases (39.3%), HGPIN in 51 cases (3.2%), histologic prostatitis in 624 cases (39.6%), BPH or no alteration (BPH/N) in 282 cases (17.9%). No difference was observed when comparing tT levels between prostatic biopsy pathologies. The tT levels were the same in prostatic cancer and benign pathology (median: 4.25 vs. 4.25 pg/mL, respectively; p=0.97). No significant correlations were observed between tT and age, tPSA, or f/t PSA ratio. Considering ROC analysis tT/tPSA ratio was a better diagnostic test than tT alone (AUC of 0.62 vs. 0.51), but inferior to the f/t PSA ratio (AUC: 0.70). In CaP patients the tT levels were not significantly different across Gleason score groups. For patients with PSA <4 ng/mL, tT was insignificantly lower in CaP patients. For these patients the best diagnostic test still was f/t PSA ratio compared to tT/tPSA ratio and to tT levels (AUC: 0.63 vs. 0.58 vs. 0.55, respectively).
The presenters concluded that tT serum values were similar between patients with differing prostate histopathology and thus don’t have any clinical utility in screening for CaP. The f/t PSA ratio still was the best diagnostic tool to help detecting CaP.
Presented by Francisco Botelho, MD, et al. at the 26th Annual European Association of Urology (EAU) Congress - March 18 - 21, 2011 - Austria Centre Vienna, Vienna, Austria