title: Specificity and accuracy of TRUS-measured PSA-density and transition zone-PSA in the diagnosis of prostate cancer.
abstract: Between 4 and 15 ng/ml serum prostate-specific antigen (PSA) has a low specificity for prostate cancer (PCa). One accepted method to enhance this specificity is transrectal ultrasonography (TRUS)-measured PSA-density (PSA-D). We compared this method with a new alternative, transition zone PSA (PSA-TZ). We measured total and transition zone prostatic volumes by TRUS and calculated PSA-D and PSA-TZ in 59 patients with suspicion of PCa and PSA between 4 and 15 ng/ml. All patients then had sextant biopsies of the prostate, 30 were positive for PCa and 29 showed benign tissue. With a cut-off value of 0.35, PSA-TZ had a positive predicted value of 77% for PCa, whereas PSA-D, with a cut-off value of 0.12, had a positive predicted value of 55%. Our data suggest PSA-TZ to be more reliable for avoiding unnecessary biopsies in patients with PCa suspicion and serum PSA below 15 ng/ml. PSA-TZ, calculated by TRUS, enhances the specificity of PSA for needle biopsy diagnosis of PCa.
authors.affiliation: Department of Urology, Dutch-speaking Brussels Free University, Laarbeeklaan 101, B-1090 Brussels, Belgium.
authors.forename: D P
authors.initials: DP
authors.lastname: Michielsen
authors.forename: V R
authors.initials: VR
authors.lastname: De Boe
authors.forename: J G
authors.initials: JG
authors.lastname: Braeckman
authors.forename: F I
authors.initials: FI
authors.lastname: Keuppens
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood; D001707:Biopsy, Needle; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000032:analysis*; D011471:Prostatic Neoplasms / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000473:pathology; D012007:Rectum / Q000000981:diagnostic imaging; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014463:Ultrasonography
chemical_list: D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen