title: Prostate specific antigen levels in young adulthood predict prostate cancer risk: results from a cohort of Black and White Americans.
abstract: OBJECTIVE
  Prostate specific antigen (PSA) is a serine protease produced by normal and malignant prostate epithelial cells. Serum PSA increases with age, due largely to age related increases in the prevalence of benign prostatic disease. Little is known about PSA distribution in young adulthood, when benign and malignant prostatic diseases are rare, or about how PSA within the normal range in youth relates to subsequent prostate cancer risk.
  
  
  METHODS
  We evaluated serum PSA and subsequent prostate cancer occurrence in a cohort of young black and white American men with a median age at blood draw of 34 years, who in 1959 to 1966 participated as the fathers of newborns enrolled in the Child Health and Development Study, and who were followed for several decades for prostate cancer. We examined associations between PSA in young adulthood and subsequent prostate cancer risk using a nested case-control design based on 119 black and 206 white cases with 2 control men matched to each case on race and year of birth.
  
  
  RESULTS
  Prostate cancer risk increased with increasing PSA in black and white men. The OR comparing risk in the highest to lowest quartiles of PSA was 4.4 (95% CI 2.0 to 9.6) in black men and 3.5 (95% CI 2.0 to 6.1) in white men. ORs relating risk to PSA were higher when analysis was restricted to cases diagnosed before age 65 years.
  
  
  CONCLUSIONS
  These findings suggest that PSA levels in young adulthood indicate increased risk of prostate cancer and, thus, they may be useful for targeting men for screening and early diagnosis.
authors.affiliation: Department of Health Research and Policy, Stanford University School of Medicine, California 94305-5405, USA. alicesw@stanford.edu
authors.forename: Alice S
authors.initials: AS
authors.lastname: Whittemore
authors.forename: Piera M
authors.initials: PM
authors.lastname: Cirillo
authors.forename: David
authors.initials: D
authors.lastname: Feldman
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Cohn
mesh_terms: D000328:Adult; D000367:Age Factors; D014408:Biomarkers, Tumor / Q000097:blood*; D044383:Black People / Q000706:statistics & numerical data*; D015331:Cohort Studies; D042241:Early Diagnosis; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000208:ethnology; D012306:Risk; D044465:White People / Q000706:statistics & numerical data*
chemical_list: D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen