title: Prostate cancer and supplementation with alpha-tocopherol and beta-carotene: incidence and mortality in a controlled trial.
abstract: BACKGROUND
  Epidemiologic studies have suggested that vitamin E and beta-carotene may each influence the development of prostate cancer. In the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, a controlled trial, we studied the effect of alpha-tocopherol (a form of vitamin E) and beta-carotene supplementation, separately or together, on prostate cancer in male smokers.
  
  
  METHODS
  A total of 29133 male smokers aged 50-69 years from southwestern Finland were randomly assigned to receive alpha-tocopherol (50 mg), beta-carotene (20 mg), both agents, or placebo daily for 5-8 years (median, 6.1 years). The supplementation effects were estimated by a proportional hazards model, and two-sided P values were calculated.
  
  
  RESULTS
  We found 246 new cases of and 62 deaths from prostate cancer during the follow-up period. A 32% decrease (95% confidence interval [CI] = -47% to -12%) in the incidence of prostate cancer was observed among the subjects receiving alpha-tocopherol (n = 14564) compared with those not receiving it (n = 14569). The reduction was evident in clinical prostate cancer but not in latent cancer. Mortality from prostate cancer was 41% lower (95% CI = -65% to -1%) among men receiving alpha-tocopherol. Among subjects receiving beta-carotene (n = 14560), prostate cancer incidence was 23% higher (95% CI = -4%-59%) and mortality was 15% higher (95% CI = -30%-89%) compared with those not receiving it (n = 14573). Neither agent had any effect on the time interval between diagnosis and death.
  
  
  CONCLUSIONS
  Long-term supplementation with alpha-tocopherol substantially reduced prostate cancer incidence and mortality in male smokers. Other controlled trials are required to confirm the findings.
authors.affiliation: Department of Public Health, University of Helsinki, Finland.
authors.forename: O P
authors.initials: OP
authors.lastname: Heinonen
authors.forename: D
authors.initials: D
authors.lastname: Albanes
authors.forename: J
authors.initials: J
authors.lastname: Virtamo
authors.forename: P R
authors.initials: PR
authors.lastname: Taylor
authors.forename: J K
authors.initials: JK
authors.lastname: Huttunen
authors.forename: A M
authors.initials: AM
authors.lastname: Hartman
authors.forename: J
authors.initials: J
authors.lastname: Haapakoski
authors.forename: N
authors.initials: N
authors.lastname: Malila
authors.forename: M
authors.initials: M
authors.lastname: Rautalahti
authors.forename: S
authors.initials: S
authors.lastname: Ripatti
authors.forename: H
authors.initials: H
authors.lastname: Mäenpää
authors.forename: L
authors.initials: L
authors.lastname: Teerenhovi
authors.forename: L
authors.initials: L
authors.lastname: Koss
authors.forename: M
authors.initials: M
authors.lastname: Virolainen
authors.forename: B K
authors.initials: BK
authors.lastname: Edwards
mesh_terms: D016588:Anticarcinogenic Agents / Q000627:therapeutic use*; D004311:Double-Blind Method; D006801:Humans; D015994:Incidence; D008297:Male; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000401:mortality / Q000517:prevention & control*; D016896:Treatment Outcome; D014810:Vitamin E / Q000627:therapeutic use*; D019207:beta Carotene / Q000627:therapeutic use*
chemical_list: D016588:Anticarcinogenic Agents; D019207:beta Carotene; D014810:Vitamin E