The percentage of free prostate-specific antigen does not predict extracapsular disease in patients with clinically localized prostate cancer before radical prostatectomy

OBJECTIVE: To determine whether the percentage of free/total prostate-specific antigen (f/tPSA) can predict the pathological features in patients with clinically localized prostate cancer before radical prostatectomy. PATIENTS AND METHODS: Univariate and multivariate logistic regression was used to analyse data from 171 untreated patients who underwent radical prostatectomy. Variables included the total PSA (tPSA), fPSA, f/tPSA, biopsy Gleason score, clinical stage and patient age. RESULTS: In 115 patients with pathologically organ-confined tumours ( pT2N0) the mean (SD) tPSA value was 6.9 (5.6) ng/mL; in 56 patients with extracapsular disease ( pT3pN0/N+) it was 10.2 (7.6) ng/mL; the respective f/tPSA values were 14.9 (8.1)% and 14.2 (12.9)%. In the univariate and multivariate analysis, tPSA and biopsy Gleason score were highly significant in predicting extracapsular disease (P < 0.001 and 0.002) but the f/tPSA was not (P = 0.18). There was no significant difference between the mean f/tPSA and final Gleason scores. CONCLUSION: The f/tPSA does not predict extracapsular disease in patients with clinically localized prostate cancer before radical prostatectomy. Knowing the f/tPSA provides no significant additional information in predicting extracapsular disease when the biopsy Gleason score and tPSA are known.