title: Prostate specific antigen density of the transition zone for predicting pathological stage of localized prostate cancer in patients with serum prostate specific antigen less than 10 ng./ml.
abstract: OBJECTIVE
  Prostate specific antigen (PSA) density of the transition zone, which is the density of serum PSA related to the volume of the transition zone, has been recently demonstrated to enhance prostate cancer prediction in patients with intermediate PSA levels. We further investigated the usefulness of PSA-transition zone for predicting extraprostatic extension in clinically localized prostate cancer.
  
  
  METHODS
  Measuring the transition zone of the prostate by ultrasound using the prolate ellipsoid method, PSA-transition zone values were calculated prospectively in 198 patients with clinically localized prostate cancers and serum PSA less than 10.0 ng./ml. who underwent radical retropubic prostatectomy. The ability of PSA-transition zone to predict extracapsular disease in the surgical specimen was compared to Gleason score, serum PSA, PSA density of the total prostate and percent free PSA using univariate or multivariate analysis as well as receiver operating characteristics curves.
  
  
  RESULTS
  A total of 104 patients (52.5%) had pathologically organ confined prostate cancer while 94 of 198 (47.5) had extracapsular disease. PSA-transition zone levels were significantly higher in extracapsular disease than organ confined cancers (0.84 versus 0.42 ng./ml./cc, p <0.00001). Using multivariate analyses PSA-transition zone and Gleason score were the most significant predictors of extracapsular disease. The area under the curve was larger for PSA-transition zone (0.825) than any other parameter (p <0.004 versus PSA density and p <0.001 versus PSA, percent free PSA or Gleason score). A cutoff of 1.00 ng./ml./cc for PSA-transition zone provided 95.1% specificity and 28.8% sensitivity for predicting extracapsular disease. Probability plots using the best combination of independent variables for predicting extraprostatic extension were developed.
  
  
  CONCLUSIONS
  These data demonstrate that the use of the PSA-transition zone may be of additional value for indicating which patients with clinically localized prostate cancer and PSA less than 10.0 ng./ml. are at high risk for extracapsular disease.
authors.affiliation: Department of Urology, Erasme Hospital, University Clinics of Brussels, Belgium.
authors.forename: A R
authors.initials: AR
authors.lastname: Zlotta
authors.forename: B
authors.initials: B
authors.lastname: Djavan
authors.forename: M
authors.initials: M
authors.lastname: Petein
authors.forename: M
authors.initials: M
authors.lastname: Susani
authors.forename: M
authors.initials: M
authors.lastname: Marberger
authors.forename: C C
authors.initials: CC
authors.lastname: Schulman
mesh_terms: D000368:Aged; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011300:Preoperative Care; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000473:pathology*; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D017430:Prostate-Specific Antigen