Comparative evaluation of total PSA, free/total PSA, and complexed PSA in prostate cancer detection.
OBJECTIVE
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.
Tanguay
S
S
Department of Surgery (Urology), McGill University, Montreal, Quebec, Canada.
Bégin
L R
LR
Elhilali
M M
MM
Behlouli
H
H
Karakiewicz
P I
PI
Aprikian
A G
AG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis*; D012372:ROC Curve; D012016:Reference Values; D012680:Sensitivity and Specificity
D017430:Prostate-Specific Antigen