title: Prostate-specific antigen adjusted for the transition zone volume versus free-to-total prostate-specific antigen ratio in predicting prostate cancer.
abstract: BACKGROUND
  We performed this study to assess the efficacy of prostate-specific antigen adjusted for the transition zone volume (PSATZ) and free-to-total prostate-specific antigen (PSA) ratio (F/T ratio) in predicting prostate cancer in men with intermediate PSA levels of 4.1-10.0 ng/mL.
  
  
  METHODS
  Between March 1997 and September 1998, PSATZ was obtained from 67 patients who underwent ultrasonography guided systemic sextant biopsies and had a PSA of 4.1-10.0 ng/mL. PSATZ was compared with F/T ratio via receiver operating characteristic (ROC) curves.
  
  
  RESULTS
  Of 67 patients, 22 (32.8%) had prostate cancer and 45 (67.2%) had benign prostatic hyperplasia (BPH) on pathologic examination. Mean PSA, PSA density, F/T ratio and PSATZ were 7.96+/-2.01ng/mL, 0.28+/-0.14 ng/mL/cc, 0.10+/-0.06 and 0.70+/-0.28 ng/mL/cc in patients with prostate cancer and 6.39+/-1.68 ng/mL, 0.16+/-0.06 ng/mL/cc, 0.15+/-0.05 and 0.29+/-0.10 ng/mL/cc in patients with BPH, respectively. The ROC curve analysis demonstrated that PSATZ predicted the biopsy outcome significantly better than F/T ratio in all 67 patients (P<0.01) and in a subset of 53 men with normal digital rectal examination (P<0.01). With a cut-off value of 0.35 ng/mL/cc, PSATZ had a sensitivity of 86% and a specificity of 89% for predicting prostate cancer.
  
  
  CONCLUSIONS
  These results suggest that PSATZ and F/T ratio may be useful in diagnosing prostate cancer with intermediate levels of PSA. Prostate-specific antigen adjusted for the transition zone volume is more accurate than F/T ratio in distinguishing benign prostatic disease from prostate cancer. But large prospective studies are required to assess the precise role of PSATZ and F/T ratio in early prostate cancer detection.
authors.affiliation: Department of Urology, Korea University College of Medicine, Seoul.
authors.forename: D G
authors.initials: DG
authors.lastname: Moon
authors.forename: J
authors.initials: J
authors.lastname: Cheon
authors.forename: J J
authors.initials: JJ
authors.lastname: Kim
authors.forename: D K
authors.initials: DK
authors.lastname: Yoon
authors.forename: S K
authors.initials: SK
authors.lastname: Koh
mesh_terms: D000367:Age Factors; D000368:Aged; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011467:Prostate / Q000473:pathology; D017430:Prostate-Specific Antigen / Q000032:analysis / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000473:pathology; D012680:Sensitivity and Specificity
chemical_list: D017430:Prostate-Specific Antigen