Diagnostic significance of [-2]pro-PSA and prostate dimension-adjusted PSA-related indices in men with total PSA in the 2.0-10.0 ng/mL range.
OBJECTIVE
One of the most important issues to address when developing an optimal screening system for prostate cancer is investigating appropriate biopsy indications following serum prostate-specific antigen (PSA) measurements in order to maintain high sensitivity and avoid unnecessary biopsy.


METHODS
Between April 2004 and December 2007, 239 consecutive men with total PSA levels of 2.0-10.0 ng/mL underwent measurements of PSA, free PSA, and [-2]pro-PSA. We assessed the significance of laboratory-based PSA-related indices including free PSA/total PSA (%f-PSA), p2PSA/free PSA (%p2PSA), p2PSA/%f-PSA, Prostate Health Index (phi, an index combining PSA, free PSA, and p2PSA), total prostate volume (TPV)-adjusted PSA-related indices, including PSA density, %p2PSA density, p2PSA/%f-PSA density, and phi density, and transition zone (TZ) prostate volume-adjusted PSA-related indices such as PSA TZ density (PSATZD), %p2PSA TZD, p2PSA/%fPSA TZD, and phi TZD.


RESULTS
The positive biopsy rate was 22.2%. When sensitivity was fixed at 95 %, unnecessary biopsies could be avoided in 28% of men when phi was used as a biopsy indication. In cases where total and transition zone prostate volumes were available, the use of %p2PSA density, phi density, p2PSA/%f-PSA TZD, and phi TZD resulted in the avoidance of 48, 47, 54, and 54 % of unnecessary biopsies, respectively, while maintaining a high sensitivity of 90%.


CONCLUSIONS
At 90 and 95 % sensitivity, laboratory-based indices containing p2PSA, particularly phi, showed significantly greater specificity for prostate cancer as compared with %f-PSA. The diagnostic accuracy of prostate volume-adjusted p2PSA-related indices could be excellent, particularly the transition zone volume-adjusted indices at fixed sensitivities of 95 and 90%.
Department of Urology, Gunma University Graduate School of Medicine, 3-39-22, Showa-machi, Maebashi, Gunma, 371-8511, Japan. kzito@med.gunma-u.ac.jp
Kazuto
K
Ito
Mai
M
Miyakubo
Yoshitaka
Y
Sekine
Hidekazu
H
Koike
Hiroshi
H
Matsui
Yasuhiro
Y
Shibata
Kazuhiro
K
Suzuki
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D001706:Biopsy; D006801:Humans; D007610:Kallikreins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood*; D011470:Prostatic Hyperplasia / Q000097:blood / Q000175:diagnosis* / Q000473:pathology; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000473:pathology; D011498:Protein Precursors / Q000097:blood*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
C583834:(-2)pro-prostate-specific antigen, human; D014408:Biomarkers, Tumor; D011498:Protein Precursors; C549870:KLK3 protein, human; D007610:Kallikreins; D017430:Prostate-Specific Antigen