Usefulness of PSA density and PSA excess in the differential diagnosis between prostate cancer and benign prostatic...

The usefulness of PSA density (PSAD) was evaluated in relation to the volume of the transitional zone (PSAT) and PSA excess. With this purpose we conducted a study including 27 patients diagnosed as having prostatic cancer (PC) and 46 patients with benign prostatic hypertrophy (BPH). In all of them, the PSA concentration in the serum was determined as well as the total prostatic volume and the transitional zone volume; digital rectal examination (DRE) was also performed. The major diagnostic efficacy was obtained with the excess of PSA (73%, cutoff = -13 ng/ml), followed by DRE (68%), PSAT (64%, cutoff = 0.5), PSAD (64%, cutoff = 0.2), and lastly PSA and ultrasonography (60%). Multivariate analysis (logistic regression) demonstrated PSA excess and DRE to be the best predictors. The model obtained by regression shows the best positive predictive value, and PSA excess the best negative predictive value. Consequently, PSA excess could be relevant in prostate cancer diagnosis.