title: Plasma carotenoids, retinol, and tocopherols and postmenopausal breast cancer risk in the Multiethnic Cohort Study: a nested case-control study.
abstract: BACKGROUND
  Assessments by the handful of prospective studies of the association of serum antioxidants and breast cancer risk have yielded inconsistent results. This multiethnic nested case-control study sought to examine the association of plasma carotenoids, retinol, and tocopherols with postmenopausal breast cancer risk.
  
  
  METHODS
  From the biospecimen subcohort of the Multiethnic Cohort Study, 286 incident postmenopausal breast cancer cases were matched to 535 controls on age, sex, ethnicity, study location (Hawaii or California), smoking status, date/time of collection and hours of fasting. We measured prediagnostic circulating levels of individual carotenoids, retinol, and tocopherols. Conditional logistic regression was used to compute odds ratios and 95% confidence intervals.
  
  
  RESULTS
  Women with breast cancer tended to have lower levels of plasma carotenoids and tocopherols than matched controls, but the differences were not large or statistically significant and the trends were not monotonic. No association was seen with retinol. A sensitivity analysis excluding cases diagnosed within 1 year after blood draw did not alter the findings.
  
  
  CONCLUSIONS
  The lack of significant associations in this multiethnic population is consistent with previously observed results from less racially-diverse cohorts and serves as further evidence against a causal link between plasma micronutrient concentrations and postmenopausal breast cancer risk.
authors.affiliation: Epidemiology Program, Cancer Research Center of Hawaii, University of Hawaii, 1236 Lauhala Street, Honolulu, HI 96813, USA. mepplein@crch.hawaii.edu
authors.forename: Meira
authors.initials: M
authors.lastname: Epplein
authors.forename: Yurii B
authors.initials: YB
authors.lastname: Shvetsov
authors.forename: Lynne R
authors.initials: LR
authors.lastname: Wilkens
authors.forename: Adrian A
authors.initials: AA
authors.lastname: Franke
authors.forename: Robert V
authors.initials: RV
authors.lastname: Cooney
authors.forename: Loïc
authors.initials: L
authors.lastname: Le Marchand
authors.forename: Brian E
authors.initials: BE
authors.lastname: Henderson
authors.forename: Laurence N
authors.initials: LN
authors.lastname: Kolonel
authors.forename: Marc T
authors.initials: MT
authors.lastname: Goodman
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000097:blood* / Q000453:epidemiology / Q000208:ethnology; D002338:Carotenoids / Q000097:blood*; D016022:Case-Control Studies; D005006:Ethnicity / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood*; D012306:Risk; D012907:Smoking / Q000097:blood / Q000453:epidemiology; D024505:Tocopherols / Q000097:blood*; D014481:United States / Q000453:epidemiology; D014801:Vitamin A / Q000097:blood*
chemical_list: D014801:Vitamin A; D002338:Carotenoids; D024505:Tocopherols