title: Usefulness of the ratio free/total prostate-specific antigen in addition to total PSA levels in prostate cancer screening.
abstract: OBJECTIVE
  Two different studies were performed. The aim of the first study was to define whether the measurement of the ratio between free and total prostate-specific antigen (f/t PSA) in serum may enhance the ability of PSA-based screening for early detection of prostate cancer in men with elevated serum PSA levels. A second study was undertaken to investigate the value of f/t PSA ratio in serum to improve the specificity of prostate cancer screening in men with serum PSA levels between 2.5 and 10.0 ng/mL.
  
  
  METHODS
  In a retrospective study of 266 men with elevated PSA levels and proven biopsy results, f/t PSA levels were measured using deep frozen serum samples. In a second study we enrolled 158 men with elevated PSA levels according to age reference ranges apparent from our current PSA screening study with additional measurement of the f/t PSA ratio. All study volunteers with a free f/t PSA ratio cutoff point of < or = 22% underwent digital rectal examination, transrectal ultrasonography, and biopsy of the prostate. Free and total PSA levels were measured with the Delfia PSA dual label f/t PSA kit (Wallac Oy Turku, Finland).
  
  
  RESULTS
  106 of 158 men with elevated total PSA values between 2.5 and 10.0 ng/mL (group 1) have been further evaluated and 37 prostate cancers were detected. Mean percentage of free PSA was 10% in men with cancer and 22% in men with benign prostatic hyperplasia. Using a f/t PSA ratio of < or = 22% as a biopsy criterion 30% of the negative biopsies could be eliminated while still detecting 98% carcinomas.
  
  
  CONCLUSIONS
  Measurement of f/t PSA reduces the number of unnecessary biopsies in PSA screening without missing many cancers.
authors.affiliation: Department of Urology, University of Innsbruck, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Reissigl
authors.forename: H
authors.initials: H
authors.lastname: Klocker
authors.forename: J
authors.initials: J
authors.lastname: Pointner
authors.forename: K
authors.initials: K
authors.lastname: Fink
authors.forename: W
authors.initials: W
authors.lastname: Horninger
authors.forename: O
authors.initials: O
authors.lastname: Ennemoser
authors.forename: H
authors.initials: H
authors.lastname: Strasser
authors.forename: K
authors.initials: K
authors.lastname: Colleselli
authors.forename: L
authors.initials: L
authors.lastname: Höltl
authors.forename: G
authors.initials: G
authors.lastname: Bartsch
mesh_terms: D000368:Aged; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000473:pathology / Q000517:prevention & control; D012372:ROC Curve; D012189:Retrospective Studies
chemical_list: D017430:Prostate-Specific Antigen