Address of Corresponding Author

Urol Int 2005;74:198-202 (DOI: 10.1159/000083548)

  Key Words

• Prostate-specific antigen
• Prostate cancer
• Intraindividual variation

  Abstract

Objectives: To investigate intraindividual total and percent free serum prostate-specific antigen (PSA) in prostate cancer suspects and to understand the clinical implications. Patients and Methods: Total and percent free PSA were measured using Tandem-R or chemiluminescent enzyme-linked immunoassay for a median of three times in 126 men. Prostate biopsies were performed in all patients; benign prostatic hyperplasia was diagnosed in 81 patients and prostate cancer in 45 patients. Results: The overall mean coefficients of variation for total and percent free PSA were 16.10 ± 11.94% and 15.45 ± 15.91%, respectively. A significant correlation (p = 0.0056) was observed between the two variations. The variations in total and percent free PSA were related to none of such stratifications as baseline total PSA level, histology, age, or measurement interval, but for measurement interval on that for total PSA. Conclusion: Intraindividual variation in serum PSA should be considered in decision-making about performing prostate biopsies. Also, care should be taken in interpreting repeated percent free PSA measurements in order to enhance the specificity of total PSA, because it had a similar variation to total PSA variation.

Copyright © 2005 S. Karger AG, Basel

  Author Contacts

Minoru Kobayashi, MD
Department of Urology, Jichi Medical School
3311-1 Yakushiji, Minamikawachi-machi, Kawachi-gun
Tochigi, 329-0498 (Japan)
Tel. +81 285 58 7379, Fax +81 285 40 6595, E-Mail minoruk@jichi.ac.jp

  Article Information

Received: November 3, 2003
Revised and accepted: September 14, 2004
Number of Print Pages : 5
Number of Figures : 1, Number of Tables : 5, Number of References : 21