title: Comparisons of the various combinations of free, complexed, and total prostate-specific antigen for the detection of prostate cancer.
abstract: OBJECTIVE
  We compared the ability of three prostate-specific antigen (PSA) ratios - free-to- total PSA ratio (fPSA/tPSA), free-to-complexed PSA ratio (fPSA/cPSA), and complexed-to-total PSA ratio (cPSA/tPSA) - to distinguish prostate cancer from benign prostatic hyperplasia (BPH).
  
  
  METHODS
  We tested 258 consecutive patients who underwent transrectal ultrasound-guided prostate needle biopsy because of an abnormal digital rectal examination or a Tandem-R PSA of >4.1 ng/ml. Free PSA (fPSA) and total PSA (tPSA) were measured by Tandem-R assay. alpha(1)-Antichymotrypsin-complexed PSA (cPSA) was measured by Markit-M PSA-ACT assay.
  
  
  RESULTS
  Of the 258 patients, 204 had BPH, and 54 had prostate cancer. The specificity at 96% sensitivity for fPSA/tPSA, fPSA/cPSA, and cPSA/tPSA was 23, 25, and 33%, respectively. Of 162 patients with tPSA between 4.1 and 10.0 ng/ml, 132 had BPH and 30 had prostate cancer. The specificity at 96% sensitivity for f/tPSA, f/cPSA and c/tPSA was 32, 44, and 41%, respectively. There was no significant difference in the area under the receiver-operating characteristic curves among fPSA/tPSA, fPSA/cPSA, and cPSA/tPSA in the overall PSA range or in tPSA between 4.1 and 10.0 ng/ml.
  
  
  CONCLUSIONS
  fPSA/tPSA, fPSA/cPSA, and cPSA/tPSA did not differ in their ability to distinguish prostate cancer from BPH.
authors.affiliation: Department of Urology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Okegawa
authors.forename: H
authors.initials: H
authors.lastname: Noda
authors.forename: K
authors.initials: K
authors.lastname: Nutahara
authors.forename: E
authors.initials: E
authors.lastname: Higashihara
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis*; D012680:Sensitivity and Specificity
chemical_list: D017430:Prostate-Specific Antigen