PSA Value Adjusted for the Transition Zone Volume in the Diagnosis of Prostate Cancer

Abstract

The aim of the present study was to improve the accuracy of the prostate-specific antigen (PSA) density for detecting prostate cancer by using the transition zone (TZ) volume instead of the total prostate volume. From April 1994 to October 1995, we examined 164 consecutive patients (52-88 years old), with an elevated PSA and/or abnormal digital rectal examination. All patients underwent a transrectal ultrasound-guided biopsy. The PSA density for total prostate volume (PSAD) and for TZ volume (PSAT) were calculated from the transrectal ultrasound measurements. Forty-four of the 162 patients (27.2%) had histological confirmation of prostate cancer on biopsy. The area under the receiver-operator characteristic curve was 0.667 for PSA, 0.663 for PSAD, and 0.826 for PSAT. These areas were not significantly different for PSA and PSAD. However, PSAT was significantly superior to PSAD in differentiating benign hyperplasia from prostate cancer (P < 0.01). The TZ volume-adjusted PSA density (PSAT) is useful for selecting patients for prostate biopsy from those with suspected prostate cancer.