title: Dietary cadmium exposure and risk of breast, endometrial, and ovarian cancer in the Women's Health Initiative.
abstract: BACKGROUND
  In vitro and animal data suggest that cadmium, a heavy metal that contaminates some foods and tobacco plants, is an estrogenic endocrine disruptor. Elevated estrogen exposure is associated with breast, endometrial, and ovarian cancer risk.
  
  
  OBJECTIVE
  We examined the association between dietary cadmium intake and risk of these cancers in the large, well-characterized Women's Health Initiative (WHI).
  
  
  METHODS
  A total of 155,069 postmenopausal women, 50-79 years of age, who were enrolled in the WHI clinical trials or observational study, participated in this study. We estimated dietary cadmium consumption by combining baseline food frequency questionnaire responses with U.S. Food and Drug Administration data on food cadmium content. Participants reported incident invasive breast, endometrial, or ovarian cancer, and WHI centrally adjudicated all cases through August 2009. We applied Cox regression to estimate adjusted hazard ratios (HRs) and 95% CIs for each cancer, comparing quintiles of energy-adjusted dietary cadmium intake.
  
  
  RESULTS
  Over an average of 10.5 years, 6,658 invasive breast cancers, 1,198 endometrial cancers, and 735 ovarian cancers were reported. We observed no statistically significant associations between dietary cadmium and risk of any of these cancers after adjustment for potential confounders including total dietary energy intake. Results did not differ in any subgroup of women examined.
  
  
  CONCLUSIONS
  We found little evidence that dietary cadmium is a risk factor for breast, endometrial, or ovarian cancers in postmenopausal women. Misclassification in dietary cadmium assessment may have attenuated observed associations.
authors.affiliation: Fred Hutchinson Cancer Research Center, Program in Cancer Prevention, Public Health Sciences Division, Seattle, Washington, USA.
authors.forename: Scott V
authors.initials: SV
authors.lastname: Adams
authors.forename: Sabah M
authors.initials: SM
authors.lastname: Quraishi
authors.forename: Martin M
authors.initials: MM
authors.lastname: Shafer
authors.forename: Michael N
authors.initials: MN
authors.lastname: Passarelli
authors.forename: Emily P
authors.initials: EP
authors.lastname: Freney
authors.forename: Rowan T
authors.initials: RT
authors.lastname: Chlebowski
authors.forename: Juhua
authors.initials: J
authors.lastname: Luo
authors.forename: Jaymie R
authors.initials: JR
authors.lastname: Meliker
authors.forename: Lina
authors.initials: L
authors.lastname: Mu
authors.forename: Marian L
authors.initials: ML
authors.lastname: Neuhouser
authors.forename: Polly A
authors.initials: PA
authors.lastname: Newcomb
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology; D002104:Cadmium / Q000008:administration & dosage / Q000032:analysis* / Q000633:toxicity; D004032:Diet / Q000706:statistics & numerical data; D016889:Endometrial Neoplasms / Q000453:epidemiology* / Q000209:etiology; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D005260:Female; D005506:Food Contamination; D015386:Hazardous Substances / Q000008:administration & dosage / Q000032:analysis* / Q000633:toxicity; D006801:Humans; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D016387:Women's Health
chemical_list: D015386:Hazardous Substances; D002104:Cadmium