Objectives: To compare the performance of prostate-specific antigen (PSA), the free/total PSA (F/T PSA) ratio, and complexed PSA (cPSA) in prostate cancer detection.
Methods: Five hundred thirty-five patients evaluated at the UROMED prostate cancer detection clinic had total PSA, free PSA, and cPSA measured before undergoing transrectal ultrasonography and sextant prostate biopsies. A direct comparison was performed between the different PSA assays to evaluate their ability to detect prostate cancer.
Results: Of the 535 patients evaluated, 38.1% had prostate cancer detected. The mean age of the entire population was 63.6 years (range 35 to 86). Abnormal digital rectal examination findings were present in 33.4% of the patients. The mean and median values of PSA and cPSA were significantly higher and the F/T PSA ratio was lower in patients with prostate cancer. The F/T PSA ratio performed better than either cPSA or total PSA. A higher specificity was observed with the F/T PSA ratio than with cPSA using either the entire patient population or subsets of patients with PSA levels between 4.0 and 10 ng/mL or 4.0 to 6.0 ng/mL.
Conclusions: The use of the F/T PSA ratio offers improved prostate cancer detection compared with either cPSA or total PSA.