title: Measures of combined antioxidant and pro-oxidant exposures and risk of overall and advanced stage prostate cancer.
abstract: OBJECTIVE
  Oxidative stress is possibly related to prostate carcinogenesis. We constructed a dietary antioxidant score, which is a measure of combined antioxidant exposures, and an oxidative balance score (OBS), which is a measure of combined antioxidant and pro-oxidant exposures. We hypothesized that both scores are inversely associated with the risk of prostate cancer (PCa).
  
  
  METHODS
  We conducted a case-cohort study among 58,279 men in the Netherlands Cohort Study. Cohort members completed a baseline questionnaire. From 1986 to 2003, 3451 patients with PCa were identified including 1196 advanced cancers (stage III/IV). The antioxidant score and the OBS were created by summing quartile and category scores of individual score constituents, which had an equal weight. Pro-oxidants were scored in the opposite way to antioxidants.
  
  
  RESULTS
  Both the antioxidant score and OBS were not associated with risk of overall PCa or PCa subgroups on the basis of disease stage. Most score constituents were not associated with the risk of PCa. Total catechin intake was associated with a decreased risk of stage IV PCa (greatest vs. lowest quartile: hazard ratio, 0.76; 95% confidence interval, 0.59-0.98).
  
  
  CONCLUSIONS
  The antioxidant score and OBS were not associated with risk of overall and advanced-stage PCa.
authors.affiliation: Department of Epidemiology, GROW School for Oncology and Developmental Biology, Maastricht University, The Netherlands. milan.geybels@maastrichtuniversity.nl
authors.forename: Milan S
authors.initials: MS
authors.lastname: Geybels
authors.forename: Bas A J
authors.initials: BA
authors.lastname: Verhage
authors.forename: Frederik J
authors.initials: FJ
authors.lastname: van Schooten
authors.forename: Piet A
authors.initials: PA
authors.lastname: van den Brandt
mesh_terms: D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage* / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D016001:Confidence Intervals; D004032:Diet; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009426:Netherlands / Q000453:epidemiology; D017063:Outcome Assessment, Health Care / Q000379:methods; D018384:Oxidative Stress / Q000502:physiology*; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D017382:Reactive Oxygen Species / Q000009:adverse effects* / Q000378:metabolism; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D017382:Reactive Oxygen Species