The value of percent free prostate specific antigen, prostate specific antigen density of the whole prostate and of the transition zone in Turkish men.

INTRODUCTION

This study was undertaken to evaluate the value of percent free prostate specific antigen (PSA), PSA density of the whole prostate (PSAD) and of the transition zone (TZPSAD) in reducing unnecessary biopsies in Turkish men with serum PSA levels between 2.5 and 20 ng/mL.

MATERIALS AND METHODS

A total of 105 patients referred for early prostate cancer detection or lower urinary tract symptoms participated in the study. All patients had serum total PSA level, PSAD, total prostate volume, and rectal examination, 43 patients had serum free PSA level, and 65 patients had TZPSAD. Using transrectal ultrasound, sextant biopsy and two additional transitional zone biopsies were performed. The value of percent PSA, PSAD, and TZPSAD in reducing unnecessary biopsies was evaluated.

RESULTS

Prostate carcinoma was detected in 25 of 105 patients (23.8%). Overall, areas under the ROC curves for percent free PSA, PSAD, and TZPSAD were 0.553, 0.595, and 0.550, respectively. In patients with a benign rectal examination, the value of percent free PSA slightly increased. On the other hand, in patients with prostate volume smaller than 50 cc, the value of percent free PSA and TZPSAD was encouraging. Areas under the ROC curves for percent free PSA, and TZPSAD were 0.615 and 0.642 respectively.

CONCLUSION

In Turkish men with intermediate serum PSA concentrations, percent free PSA, PSAD, and TZPSAD are poor predictors of biopsy outcome, whereas in the prostate smaller than 50 cc, percent free PSA and TZPSAD provide additional information. This may reflect ethnic differences between this population and those reported in other series.