title: Antioxidant supplement use after breast cancer diagnosis and mortality in the Life After Cancer Epidemiology (LACE) cohort.
abstract: BACKGROUND
  There is concern that antioxidant supplement use during chemotherapy and radiation therapy may decrease treatment effects, yet the effects of such supplements on recurrence and survival are largely unknown.
  
  
  METHODS
  The authors prospectively examined the associations between antioxidant use after breast cancer (BC) diagnosis and BC outcomes in 2264 women in the Life After Cancer Epidemiology (LACE) cohort. The cohort included women who were diagnosed with early stage, primary BC from 1997 to 2000 who enrolled, on average, 2 years postdiagnosis. Baseline data were collected on antioxidant supplement use since diagnosis and other factors. BC recurrence and mortality were ascertained, and hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using delayed entry Cox proportional hazards models. All tests of statistical significance were 2-sided.
  
  
  RESULTS
  Antioxidant supplement use after diagnosis was reported by 81% of women. Among antioxidant users, frequent use of vitamin C and vitamin E was associated with a decreased risk of BC recurrence (vitamin C: HR, 0.73; 95% CI, 0.55-0.97; vitamin E: HR, 0.71; 95% CI, 0.54-0.94); and vitamin E use was associated with a decreased risk of all-cause mortality (HR, 0.76; 95% CI, 0.58-1.00). Conversely, frequent use of combination carotenoids was associated with increased risk of death from BC (HR, 2.07; 95% CI, 1.21-3.56) and all-cause mortality (HR, 1.75; 95% CI, 1.13-2.71).
  
  
  CONCLUSIONS
  Frequent use of vitamin C and vitamin E in the period after BC diagnosis was associated with a decreased likelihood of recurrence, whereas frequent use of combination carotenoids was associated with increased mortality. The effects of antioxidant supplement use after diagnosis likely differ by type of antioxidant.
authors.affiliation: Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York, USA. hg2120@columbia.edu
authors.forename: Heather
authors.initials: H
authors.lastname: Greenlee
authors.forename: Marilyn L
authors.initials: ML
authors.lastname: Kwan
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Kushi
authors.forename: Jun
authors.initials: J
authors.lastname: Song
authors.forename: Adrienne
authors.initials: A
authors.lastname: Castillo
authors.forename: Erin
authors.initials: E
authors.lastname: Weltzien
authors.forename: Charles P
authors.initials: CP
authors.lastname: Quesenberry
authors.forename: Bette J
authors.initials: BJ
authors.lastname: Caan
mesh_terms: D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000627:therapeutic use; D001205:Ascorbic Acid / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy / Q000401:mortality*; D002338:Carotenoids / Q000627:therapeutic use; D015331:Cohort Studies; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000517:prevention & control; D016896:Treatment Outcome; D014810:Vitamin E / Q000627:therapeutic use
chemical_list: D000975:Antioxidants; D014810:Vitamin E; D002338:Carotenoids; D001205:Ascorbic Acid