Methods. The PSA, PSA density (PSAD), and PSATZ were determined in 101 patients with intermediate levels of serum PSA. The relationship of these parameters to prostate cancer detection was examined.

Results. Patients with prostate cancer had significantly higher PSAD and PSATZ values than those without prostate cancer. In patients with a PSA value of 4.1–10 ng/ml, especially in those without abnormal digital rectal examination findings, PSATZ was superior to PSA as an indicator for positive biopsy when analyzed by receiver operating characteristics curves. In those patients with a cutoff value of 0.3 ng/ml per ml of transition zone volume, PSATZ had a sensitivity of 79% and a specificity of 51%. A cutoff value of 0.3 for PSATZ provided a sensitivity of 88% and a specificity of 51% in patients without abnormal digital rectal examination findings.

Conclusion. The present study demonstrated that PSATZ was superior to PSA as an indicator for positive biopsy, especially in patients with normal digital rectal examination findings. PSATZ was not superior to PSAD in the detection of prostate cancer.