Percent Free Prostate-Specific Antigen: Entering a New Era in the Detection of Prostate Cancer  Apoorva R. Vashi, M.D., Joseph E. Oesterling, M.D.  Mayo Clinic Proceedings  Volume 72, Issue 4, Pages 337-344 (April 1997) DOI: 10.4065/72.4.337 Copyright © 1997 Mayo Foundation for Medical Education and Research Terms and Conditions

Fig. 1 Determination of prostate-specific antigen (PSA) reflex range with best performance for percent free PSA. Bar graph illustrates that total PSA range of 3.0 to 10.0 ng/mL demonstrates maximal improvement of percent free PSA over total PSA. (From Vashi and colleagues.38 By permission.) Mayo Clinic Proceedings 1997 72, 337-344DOI: (10.4065/72.4.337) Copyright © 1997 Mayo Foundation for Medical Education and Research Terms and Conditions

Fig. 2 Receiver operating characteristic curves for distinguishing prostate cancer from benign prostate disease, comparing percent free prostate-specific antigen (PSA) to total PSA in reflex range subset of 3.0 to 4.0 ng/mL. Areas under the receiver operating characteristic curves for percent free PSA and total PSA are 0.78 and 0.40, respectively (P<0.01). (From Vashi and associates.38 By permission.) Mayo Clinic Proceedings 1997 72, 337-344DOI: (10.4065/72.4.337) Copyright © 1997 Mayo Foundation for Medical Education and Research Terms and Conditions

Fig. 3 Receiver operating characteristic curves for distinguishing prostate cancer from benign prostate disease, comparing percent free prostate-specific antigen (PSA) to total PSA in reflex range subset of 4.1 to 10.0 ng/mL. Areas under the receiver operating characteristic curves for percent free PSA and total PSA are 0.71 and 0.52, respectively (P<0.05). (From Vashi and coworkers.38 By permission.) Mayo Clinic Proceedings 1997 72, 337-344DOI: (10.4065/72.4.337) Copyright © 1997 Mayo Foundation for Medical Education and Research Terms and Conditions

Fig. 4 Diagnostic algorithm for detecting early, curable prostate cancer by using percent free prostate-specific antigen (PSA). DRE = digital rectal examination; TRUS = transrectal ultrasonographic. Mayo Clinic Proceedings 1997 72, 337-344DOI: (10.4065/72.4.337) Copyright © 1997 Mayo Foundation for Medical Education and Research Terms and Conditions