Send to

Choose Destination
See comment in PubMed Commons below
J Urol. 2002 Sep;168(3):922-5.

Robustness of free prostate specific antigen measurements to reduce unnecessary biopsies in the 2.6 to 4.0 ng./ml. range.

Author information

Division of Urologic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri, USA.



Prostate specific antigen (PSA) cutoffs lower than 4.0 ng./ml. are being evaluated more frequently but lower PSA cutoffs increase the number of prostatic biopsies. PSA exists in several forms free and complexed to proteins. Percent free PSA is lower in men with prostate cancer. Accordingly, free PSA and complexed PSA have been used to distinguish between cancer and benign disease in the diagnostic gray zone of 4 to 10 ng./ml. to eliminate unnecessary biopsies. There are limited data on the robustness of free PSA measurements in the 2.6 to 4.0 ng./ml. total PSA range.


We evaluated percent free PSA measurements to discriminate between cancer and benign conditions in 965 consecutive volunteers in a prostate cancer screening study who underwent prostatic biopsy for a PSA of 2.6 to 4.0 ng./ml. and had benign digital rectal examination.


Overall 25% of men had cancer detected. A 25% free PSA cutoff detected 85% of cancers and avoided 19% of negative (cancer-free) biopsies, while a 30% free PSA cutoff detected 93% of cancers and avoided only 9% of negative biopsies. Of those men who underwent radical prostatectomy 132 (80%) had pathologically organ confined tumors. Only 5% of these tumors fulfilled the published pathological criteria for possibly clinically unimportant tumors.


Percent free PSA provides risk assessment but does not eliminate many unnecessary prostatic biopsies while maintaining a high sensitivity in the narrow total PSA range of 2.6 to 4.0 ng./ml.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center