title: Free to total prostate-specific antigen (PSA) ratio is superior to total-PSA in differentiating benign prostate hypertrophy from prostate cancer.
abstract: BACKGROUND
  Serum prostate-specific antigen (PSA) exists in different molecular forms, and their respective concentration has been proposed as a useful tool to improve discrimination between benign prostatic hypertrophy (BPH) and prostate cancer (PC).
  
  
  METHODS
  The relevance of the free to total PSA ratio was prospectively studied in a selected urology clinic population of 420 patients. Total serum PSA ranged from 2.1 to 30 ng/ml; 154 had PC and 266 had BPH.
  
  
  RESULTS
  Receiver operating characteristic (ROC) curves were constructed for the total population (total-PSA range from 2.1 to 30 ng/ml) and for the diagnostic gray zone of 2.1-10 ng/ml. For the two groups, the free to total PSA ratio had a higher specificity than total-PSA for all sensitivity levels. Cut-off values were found to, vary with prostate weight.
  
  
  CONCLUSIONS
  Although free to total PSA ratio demonstrated better performances than total-PSA, its use in screening appears problematic, due to the low prevalence of prostate cancer.
authors.affiliation: Department of Urology, Saint Luc University Hospital, Brussels, Belgium.
authors.forename: P J
authors.initials: PJ
authors.lastname: Van Cangh
authors.forename: P
authors.initials: P
authors.lastname: De Nayer
authors.forename: P
authors.initials: P
authors.lastname: Sauvage
authors.forename: B
authors.initials: B
authors.lastname: Tombal
authors.forename: M
authors.initials: M
authors.lastname: Elsen
authors.forename: F
authors.initials: F
authors.lastname: Lorge
authors.forename: R
authors.initials: R
authors.lastname: Opsomer
authors.forename: F X
authors.initials: FX
authors.lastname: Wese
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D006801:Humans; D007118:Immunoassay; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000032:analysis*; D011470:Prostatic Hyperplasia / Q000175:diagnosis*; D011471:Prostatic Neoplasms / Q000175:diagnosis*; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D017430:Prostate-Specific Antigen