title: Baseline prostate-specific antigen measurements and subsequent prostate cancer risk in the Danish Diet, Cancer and Health cohort.
abstract: OBJECTIVE
  Although prostate-specific antigen (PSA) screening reduces mortality from prostate cancer, substantial over-diagnosis and subsequent overtreatment are concerns. Early screening of men for PSA may serve to stratify the male population by risk of future clinical prostate cancer.
  
  
  METHODS
  Case-control study nested within the Danish 'Diet, Cancer and Health' cohort of 27,179 men aged 50-64 at enrolment. PSA measured in serum collected at cohort entry in 1993-1997 was used to evaluate prostate cancer risk diagnosed up to 14 years after. We identified 911 prostate cancer cases in the Danish Cancer Registry through 31st December 2007 1:1 age-matched with cancer-free controls. Aggressive cancer was defined as ≥ T3 or Gleason score ≥ 7 or N1 or M1. Statistical analyses were based on conditional logistic regression with age as underlying time axis.
  
  
  RESULTS
  Total PSA and free-to-total PSA ratio at baseline were strongly associated with prostate cancer risk up to 14 years later. PSA was grouped in quintiles and free-to-total PSA ratio divided in three risk groups. The incidence rate ratio for prostate cancer was 150 (95% confidence interval, 72-310) among men with a total PSA in the highest quintile (> 5.1 ng/ml) compared to the lowest (< 0.80 ng/ml). The risk of aggressive cancer was highly elevated in men with a PSA level in the highest quintile. The results indicate that one-time measurement of PSA could be used in an individualised screening strategy, sparing a large proportion of men from further PSA-based screening.
authors.affiliation: Danish Cancer Society Research Center, Strandboulevarden 49, 2100 Copenhagen Ø, Denmark. benzon@cancer.dk
authors.forename: Signe Benzon
authors.initials: SB
authors.lastname: Larsen
authors.forename: Klaus
authors.initials: K
authors.lastname: Brasso
authors.forename: Peter
authors.initials: P
authors.lastname: Iversen
authors.forename: Jane
authors.initials: J
authors.lastname: Christensen
authors.forename: Michael
authors.initials: M
authors.lastname: Christiansen
authors.forename: Sigrid
authors.initials: S
authors.lastname: Carlsson
authors.forename: Hans
authors.initials: H
authors.lastname: Lilja
authors.forename: Søren
authors.initials: S
authors.lastname: Friis
authors.forename: Anne
authors.initials: A
authors.lastname: Tjønneland
authors.forename: Susanne Oksbjerg
authors.initials: SO
authors.lastname: Dalton
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D004032:Diet; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis* / Q000453:epidemiology; D012307:Risk Factors
chemical_list: D017430:Prostate-Specific Antigen
keywords: Baseline; Nested case–control study; Prostate neoplasm; Prostate-specific antigen; Risk factor