[Clinical utility of available diagnostic tests in prostatic carcinoma. Results of 500 biopsies. I. PSA, PSA density, and predicted PSA].

OBJECTIVE: To study the utility of PSA density and predicted PSA results in the diagnosis of prostatic cancer using gland volume. METHODS: 500 patients suspected as having prostatic cancer underwent ultrasound-guided transrectal biopsy. Prostate volume and ultrasound characteristics, serum PSA density, predicted PSA and the difference between both were determined. RESULTS: 44.8% of the patients showed evidence of cancer in the biopsy specimen. These patients had a significantly smaller prostate. The 0.1 and 0.15 PSA density cutoffs had a sensitivity of 96% and 94%, specificity of 10% and 20% and positive predictive value of 46% and 49%, respectively. The statistical values for PSA difference of 1 and 2 were 94% and 92%, 13% and 18%, 47% and 48%, respectively. CONCLUSION: PSA density and predicted PSA results could be useful to avoid biopsies in patients with PSA between 4 and 10 ng/ml and no malignant tumor of the prostate.