Comparison of several combinations of free, complexed, and total PSA in the diagnosis of prostate cancer in patients with urologic symptoms

Urology. 2004 Jun;63(6):1100-3; discussion 1103-4. doi: 10.1016/j.urology.2004.01.056.

Abstract

Objectives: To compare the diagnostic efficacy of prostate-specific antigen (PSA) and the PSA fractions (free PSA [fPSA] and complexed PSA [cPSA]) in the differential diagnosis between prostate cancer and benign prostatic hyperplasia.

Methods: We measured the serum levels of total PSA (tPSA; Hybritech and Bayer), fPSA (Hybritech), and cPSA (Bayer) in 72 patients with prostate cancer and 128 patients with benign prostatic hyperplasia.

Results: Receiver operating characteristic curves were used for comparison of these tests. The greatest area under the curve was observed for the fPSA/cPSA ratio and the fPSA/tPSA ratio (0.757 and 0.754, respectively). The substitution of the fPSA/tPSA ratio with the fPSA/cPSA ratio in the diagnostic scheme of prostate cancer improved the diagnostic accuracy, with similar sensitivity and an increment in specificity (41% versus 45%).

Conclusions: The fPSA/cPSA ratio ensures a reduction in negative biopsies in the PSA gray zone. We suggest substituting the fPSA/tPSA ratio with the fPSA/cPSA ratio for patients with a PSA level between 4 and 10 ng/mL.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Area Under Curve
  • Biomarkers, Tumor / blood*
  • Biopsy
  • Diagnosis, Differential
  • Humans
  • Male
  • Palpation
  • Predictive Value of Tests
  • Prostate-Specific Antigen / blood*
  • Prostatic Hyperplasia / blood
  • Prostatic Hyperplasia / diagnosis*
  • Prostatic Neoplasms / blood
  • Prostatic Neoplasms / diagnosis*
  • Prostatic Neoplasms / pathology
  • ROC Curve
  • Regression Analysis
  • Sensitivity and Specificity

Substances

  • Biomarkers, Tumor
  • Prostate-Specific Antigen