title: Effect of finasteride on free and total serum prostate-specific antigen in men with benign prostatic hyperplasia.
abstract: OBJECTIVE
  To examine changes in the free-to-total (f/t) serum prostate-specific antigen (PSA) ratio among men treated with finasteride for benign prostatic hypertrophy.
  
  
  METHODS
  Blood samples were taken from 20 men (mean age 71 years, range 61-87) before and after a minimum of 9 months of treatment with finasteride and the f/tPSA ratio determined using the Immulite assay system.
  
  
  RESULTS
  Although mean total and free PSA levels decreased significantly, the mean f/tPSA ratio increased only slightly and not significantly; the ratios remained unchanged in men with an initially low or high (< > 10%) ratio.
  
  
  CONCLUSIONS
  Concern has been expressed over the loss of the discriminatory power of serum PSA in a patient receiving treatment with finasteride. The f/tPSA ratio, currently used to help differentiate benign from malignant processes in the prostate, remains valid during treatment with finasteride; it does not affect the f/tPSA ratio.
authors.affiliation: Department of Urology, Tel-Aviv University, Israel.
authors.forename: H
authors.initials: H
authors.lastname: Matzkin
authors.forename: M
authors.initials: M
authors.lastname: Barak
authors.forename: Z
authors.initials: Z
authors.lastname: Braf
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D018120:Finasteride / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011470:Prostatic Hyperplasia / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy*; D012680:Sensitivity and Specificity
chemical_list: D004791:Enzyme Inhibitors; D018120:Finasteride; D017430:Prostate-Specific Antigen