title: The association between vitamin C and vitamin E supplement use before hematopoietic stem cell transplant and outcomes to two years.
abstract: OBJECTIVE
  To examine the prevalence of supplement use in persons before receiving hematopoietic stem cell transplant (HSCT) and the association of select supplements with outcomes.
  
  
  METHODS
  This observational cohort study included a questionnaire on supplement use before HSCT. Nonrelapse mortality, recurrence/relapse, and mortality or relapse (the inverse of disease-free survival) were followed to two years. Subjects/Setting Persons receiving HSCT at the Fred Hutchinson Cancer Research Center between September 1994 and December 1997 were eligible (N=1,182). Statistical Analyses Performed Descriptive statistics and univariate and Cox regression analyses were conducted.
  
  
  RESULTS
  Sixty-six percent of patients used supplements (31% vitamin C, 19% vitamin E, and 20% herbs or others preparations). Vitamin C at > or =500 mg/day was inversely associated with recurrence among persons with breast cancer (RR=0.11; 95% CI, 0.02-0.89; P=.03). However, among persons with acute leukemia, vitamin C at > or =500 mg/day was positively associated with nonrelapse mortality (RR=2.25; 95% CI, 1.33-3.83; P=.01) and mortality or relapse (RR=1.63; 95% CI, 1.09-2.44; P=.01), respectively. Vitamin E at > or =400 IU/day was positively associated with mortality or relapse (RR=1.77; 95% CI, 1.06 -2.96; P=.02). Applications/Conclusions Though this work was observational, the results suggest supplemental vitamin C before therapy may be beneficial in persons with breast cancer but both vitamin C and vitamin E may increase risk in persons with acute leukemia receiving HSCT. Practitioners should document supplement use in subjects receiving therapy for cancer.
authors.affiliation: Department of Epidemiology, Nutritional Sciences Program, University of Washington, Box 353410, 305-M Raitt Hall, Seattle, WA 98105, USA. bbruemme@u.washington.edu
authors.forename: Barbara
authors.initials: B
authors.lastname: Bruemmer
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Patterson
authors.forename: Carrie
authors.initials: C
authors.lastname: Cheney
authors.forename: Saundra N
authors.initials: SN
authors.lastname: Aker
authors.forename: Robert P
authors.initials: RP
authors.lastname: Witherspoon
mesh_terms: D000293:Adolescent; D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage / Q000378:metabolism; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism / Q000401:mortality / Q000628:therapy; D015331:Cohort Studies; D019587:Dietary Supplements; D018572:Disease-Free Survival; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods* / Q000401:mortality; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000378:metabolism / Q000401:mortality / Q000628:therapy; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism / Q000401:mortality / Q000628:therapy; D008297:Male; D008875:Middle Aged; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000378:metabolism / Q000401:mortality / Q000628:therapy; D016016:Proportional Hazards Models; D014810:Vitamin E / Q000008:administration & dosage* / Q000378:metabolism
chemical_list: D000975:Antioxidants; D014810:Vitamin E; D001205:Ascorbic Acid