title: Prostate-specific antigen corrected for prostate volume improves differentiation of benign prostatic hyperplasia and organ-confined prostatic cancer.
abstract: OBJECTIVE
  To determine whether the ratio of PSA and prostate volume provides additional useful information for the discrimination of benign prostatic hyperplasia from prostatic carcinoma.
  
  
  METHODS
  Since 1989, a prospective study has been in progress involving 229 patients (49 with locally confined prostatic carcinoma, 180 with benign prostatic hyperplasia) to establish whether the ratio of prostate-specific antigen (PSA) and prostate volume, determined by transrectal ultrasound (longitudinal x anterior-posterior x transverse diameter x 0.52), allows a better differentiation than the absolute PSA values.
  
  
  RESULTS
  In this population of patients with prostatic disease, the positive predictive value for diagnosis of a prostatic carcinoma was 26% with an absolute PSA threshold value of 4.0 ng/ml, and 36% at a threshold value of 10 ng/ml. With a threshold value of the PSA/prostate volume ratio of 0.25 ng/(ml x cm3), the positive predictive value was 56% compared with 93% for a threshold value of 0.4 ng/(ml x cm3).
  
  
  CONCLUSIONS
  The ratio PSA/prostate volume is a superior method for the diagnosis of prostatic carcinoma both with regard to its sensitivity and its specificity in patients with absolute PSA values in excess of 4 ng/ml.
authors.affiliation: Department of Urology, University of Münster, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Semjonow
authors.forename: M
authors.initials: M
authors.lastname: Hamm
authors.forename: P
authors.initials: P
authors.lastname: Rathert
authors.forename: L
authors.initials: L
authors.lastname: Hertle
mesh_terms: D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011467:Prostate / Q000000981:diagnostic imaging / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood*; D011470:Prostatic Hyperplasia / Q000097:blood / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology*; D014463:Ultrasonography
chemical_list: D017430:Prostate-Specific Antigen