title: Clinical utility of the percentage of positive prostate biopsies in defining biochemical outcome after radical prostatectomy for patients with clinically localized prostate cancer.
abstract: OBJECTIVE
  To determine the clinical utility of the percentage of positive prostate biopsies in predicting prostate-specific antigen (PSA) outcome after radical prostatectomy (RP) for men with PSA-detected or clinically palpable prostate cancer.
  
  
  METHODS
  A Cox regression multivariable analysis was used to determine whether the percentage of positive prostate biopsies provided clinically relevant information about PSA outcome after RP in 960 men while accounting for the previously established risk groups that are defined according to pretreatment PSA level, biopsy Gleason score, and the 1992 American Joint Committee on Cancer (AJCC) clinical T stage. The findings were then tested using an independent surgical database that included data for 823 men.
  
  
  RESULTS
  Controlling for the known prognostic factors, the percentage of positive prostate biopsies added clinically significant information (P <.0001) regarding time to PSA failure after RP. Specifically, 80% of the patients in the intermediate-risk group (1992 AJCC T2b, or biopsy Gleason 7 or PSA > 10 ng/mL and </= 20 ng/mL) could be classified into either an 11% or 86% 4-year PSA control cohort using the preoperative prostate biopsy data. These findings were validated in the intermediate-risk patients using an independent surgical data set.
  
  
  CONCLUSIONS
  The validated stratification of PSA outcome after RP using the percentage of positive prostate biopsies in intermediate-risk patients is clinically significant. This information can be used to identify men with newly diagnosed and clinically localized prostate cancer who are at high risk for early (</= 2 years) PSA failure and, therefore, may benefit from the use of adjuvant therapy.
authors.affiliation: Joint Center for Radiation Therapy, Harvard Medical School, Boston, MA 02215, USA. adamico@jcrt.harvard.edu
authors.forename: A V
authors.initials: AV
authors.lastname: D'Amico
authors.forename: R
authors.initials: R
authors.lastname: Whittington
authors.forename: S B
authors.initials: SB
authors.lastname: Malkowicz
authors.forename: D
authors.initials: D
authors.lastname: Schultz
authors.forename: J
authors.initials: J
authors.lastname: Fondurulia
authors.forename: M H
authors.initials: MH
authors.lastname: Chen
authors.forename: J E
authors.initials: JE
authors.lastname: Tomaszewski
authors.forename: A A
authors.initials: AA
authors.lastname: Renshaw
authors.forename: A
authors.initials: A
authors.lastname: Wein
authors.forename: J P
authors.initials: JP
authors.lastname: Richie
mesh_terms: D001706:Biopsy; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology* / Q000601:surgery; D012307:Risk Factors; D017211:Treatment Failure
chemical_list: D017430:Prostate-Specific Antigen