Use of percentage of free prostate-specific antigen to identify men at high risk of prostate cancer when PSA levels are 2.51 to 4 ng/ml and digital rectal examination is not suspicious for prostate cancer: An alternative model

William J. Catalona, Alan Wayne Partin, Judith A. Finlay, Daniel Wan-Yui Chan, Harry G. Rittenhouse, Robert L. Wolfert, David L. Woodrum

Research output: Contribution to journalArticle


Objectives. Currently, many clinicians do not recommend prostate biopsy for men with digital rectal examination (DRE) results that are not suspicious for cancer and prostate-specific antigen (PSA) values between 2.51 and 4 ng/mL. We propose a new model for the detection of prostate cancer using the percentage of free PSA (%FPSA) in the limited range of PSA values between 2.51 and 4 ng/mL that maximizes clinical specificity (ie, minimizes false- positive results). This model identifies higher risk patients in this relatively low-risk population. Methods. Three hundred sixty-eight archived serum samples from men evaluated and treated at two academic institutions were reviewed. All men had a histologic diagnosis, findings not suspicious for cancer on DRE, and PSA levels between 2.51 and 4 ng/mL. Samples were tested in Hybritech's Tandem-R PSA and Tandem-R free PSA (FPSA) assays in the same laboratory at each institution. Results. Various models for cancer detection using %FPSA when PSA is 2.51 to 4 ng/mL and DRE is not suspicious for cancer are proposed. These models recommend biopsy for only 10% to 36% of the men in this population and would identify as many as 30% to 54% of the detectable cancers. There is evidence that the cancers that would be detected are the most aggressive cancers in this population. Conclusions. Our models identified men with a higher risk of prostate cancer in a relatively low-risk population that currently does not routinely undergo biopsy. This may allow for a more cost-effective way to increase cancer detection when PSA values are between 2.51 and 4 ng/mL and DRE is not suspicious for cancer. This model has the potential to detect a greater number of clinically important and potentially curable cancers than would be detected with current practice.

Original languageEnglish (US)
Pages (from-to)220-224
Number of pages5
Issue number2
Publication statusPublished - Aug 1999


ASJC Scopus subject areas

  • Urology

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