title: Systematic review of pretreatment prostate-specific antigen velocity and doubling time as predictors for prostate cancer.
abstract: OBJECTIVE
  Pretreatment prostate-specific antigen (PSA) dynamics (PSA velocity and PSA doubling time) are widely advocated as useful prognostic markers in prostate cancer. We aimed to assess the published evidence for the clinical utility of PSA dynamics in this population.
  
  
  METHODS
  We conducted a systematic review of studies published before March 2007 in which a PSA dynamic (velocity or doubling time) was calculated in patients before definitive treatment, a subsequent event (such as biopsy or recurrence) was ascertained, and the association between the two was analyzed. Our principal end point was the type of analysis reported, particularly whether the predictive accuracy of a statistical model that included both absolute PSA level and a PSA dynamic was compared with that of a model that included only PSA.
  
  
  RESULTS
  Eighty-seven articles were eligible for analysis. The most common end points were biopsy (42 articles), and either recurrence (14 articles) or metastases or death (14 articles) after definitive therapy. Although PSA dynamics were generally found to be associated with outcome, only one article compared predictive accuracy of models with and without a PSA dynamic: this reported that PSA velocity improved prediction slightly (from 0.81 to 0.83), but was subject to verification bias. No article used decision analytic methods to examine the clinical impact of PSA dynamics.
  
  
  CONCLUSIONS
  There is little evidence that calculation of PSA velocity or doubling time in untreated patients provides predictive information beyond that provided by absolute PSA level alone. We see no justification for the use of PSA dynamics in clinical decision making before treatment in early-stage prostate cancer.
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA. vickersa@mskcc.org
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Vickers
authors.forename: Caroline
authors.initials: C
authors.lastname: Savage
authors.forename: M Frank
authors.initials: MF
authors.lastname: O'Brien
authors.forename: Hans
authors.initials: H
authors.lastname: Lilja
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood; D001706:Biopsy; D006801:Humans; D008297:Male; D015233:Models, Statistical; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000401:mortality / Q000628:therapy
chemical_list: D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen