title: Volume-adjusted prostate-specific antigen (PSA) variables in detecting impalpable prostate cancer in men with PSA levels of 2-4 ng/mL: transabdominal measurement makes a significant contribution.
abstract: OBJECTIVE
  To examine whether prostate-specific antigen (PSA) levels adjusted according to prostate volume improve prostate cancer detection using transrected biopsies in men with PSA levels of 2-4 ng/mL, and benign findings on a digital rectal examination (DRE).
  
  
  METHODS
  Men aged < or = 79 years and with serum PSA levels of 2-4 ng/mL and normal DRE findings were prospectively enrolled. Eligible patients were recommended for transrectal prostate biopsies after measuring prostate volumes with transrectal (TRUS) and transabdominal (TAUS) ultrasonography, and transition zone volumes with TRUS. In addition to PSA levels and the free-to-total PSA ratio, volume-adjusted PSA levels, PSA densities determined by TRUS (PSAD(TRUS)), and TAUS (PSAD(TAUS)), and PSA transition zone densities (PSATzD) were compared using receiver operating characteristic analysis.
  
  
  RESULTS
  Prostate cancer was diagnosed in 31 (22%) of the 139 men who had prostate biopsies. The area under the curve (AUC) of PSAD(TRUS) (0.796) and PSATzD (0.792) was similar and significantly greater than that of PSA (AUC 0.588) and the free-to-total PSA ratio (AUC 0.658). PSAD(TAUS) was a significantly better indicator of prostate cancer than PSA levels alone (P = 0.043).
  
  
  CONCLUSIONS
  As predictors of prostate cancer, there were no significant differences between PSAD(TRUS) and PSATzD. Although PSAD(TAUS) was worse than PSA variables adjusted by total and transition zone prostate volumes determined by TRUS, it was a better predictor than the PSA value alone in men with a low PSA level. These results indicate that TAUS is worthwhile where the routine use of TRUS before biopsy is difficult.
authors.affiliation: Department of Urology, Hamamatsu Rosai Hospital, Hamamatsu, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawahara
authors.forename: Koji
authors.initials: K
authors.lastname: Nishizawa
authors.forename: Keiji
authors.initials: K
authors.lastname: Ogura
authors.forename: Kenji
authors.initials: K
authors.lastname: Mitsumori
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ide
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy / Q000379:methods / Q000592:standards; D006801:Humans; D008297:Male; D008875:Middle Aged; D010173:Palpation / Q000379:methods; D011446:Prospective Studies; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D012372:ROC Curve; D012007:Rectum; D012680:Sensitivity and Specificity
chemical_list: D017430:Prostate-Specific Antigen