title: The relationship between prostate-specific antigen and prostate cancer risk: the Prostate Biopsy Collaborative Group.
abstract: OBJECTIVE
  The relationship between prostate-specific antigen (PSA) level and prostate cancer risk remains subject to fundamental disagreements. We hypothesized that the risk of prostate cancer on biopsy for a given PSA level is affected by identifiable characteristics of the cohort under study.
  
  
  METHODS
  We used data from five European and three U.S. cohorts of men undergoing biopsy for prostate cancer; six were population-based studies and two were clinical cohorts. The association between PSA and prostate cancer was calculated separately for each cohort using locally weighted scatterplot smoothing.
  
  
  RESULTS
  The final data set included 25,772 biopsies and 8,503 cancers. There were gross disparities between cohorts with respect to both the prostate cancer risk at a given PSA level and the shape of the risk curve. These disparities were associated with identifiable differences between cohorts: for a given PSA level, a greater number of biopsy cores increased the risk of cancer (odds ratio for >6- versus 6-core biopsy, 1.35; 95% confidence interval, 1.18-1.54; P < 0.0005); recent screening led to a smaller increase in risk per unit change in PSA (P = 0.001 for interaction term) and U.S. cohorts had higher risk than the European cohorts (2.14; 95% confidence interval, 1.99-2.30; P < 0.0005).
  
  
  CONCLUSIONS
  Our results suggest that the relationship between PSA and risk of a positive prostate biopsy varies, both in terms of the probability of prostate cancer at a given PSA value and the shape of the risk curve. This poses challenges to the use of PSA-driven algorithms to determine whether biopsy is indicated.
authors.affiliation: Memorial Sloan-Kettering Cancer Center, New York, NY, USA. vickersa@mskcc.org
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Vickers
authors.forename: Angel M
authors.initials: AM
authors.lastname: Cronin
authors.forename: Monique J
authors.initials: MJ
authors.lastname: Roobol
authors.forename: Jonas
authors.initials: J
authors.lastname: Hugosson
authors.forename: J Stephen
authors.initials: JS
authors.lastname: Jones
authors.forename: Michael W
authors.initials: MW
authors.lastname: Kattan
authors.forename: Eric
authors.initials: E
authors.lastname: Klein
authors.forename: Freddie
authors.initials: F
authors.lastname: Hamdy
authors.forename: David
authors.initials: D
authors.lastname: Neal
authors.forename: Jenny
authors.initials: J
authors.lastname: Donovan
authors.forename: Dipen J
authors.initials: DJ
authors.lastname: Parekh
authors.forename: Donna
authors.initials: D
authors.lastname: Ankerst
authors.forename: George
authors.initials: G
authors.lastname: Bartsch
authors.forename: Helmut
authors.initials: H
authors.lastname: Klocker
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Horninger
authors.forename: Amine
authors.initials: A
authors.lastname: Benchikh
authors.forename: Gilles
authors.initials: G
authors.lastname: Salama
authors.forename: Arnauld
authors.initials: A
authors.lastname: Villers
authors.forename: Steve J
authors.initials: SJ
authors.lastname: Freedland
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Moreira
authors.forename: Fritz H
authors.initials: FH
authors.lastname: Schröder
authors.forename: Hans
authors.initials: H
authors.lastname: Lilja
mesh_terms: D000368:Aged; D001706:Biopsy; D005060:Europe; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000032:analysis*; D011471:Prostatic Neoplasms / Q000473:pathology*; D018570:Risk Assessment; D012307:Risk Factors; D014481:United States
chemical_list: D017430:Prostate-Specific Antigen