title: Breast cancer frequency and exposure to cadmium: a meta- analysis and systematic review.
abstract: BACKGROUND
  In this meta-analysis we review evidence suggesting that exposure to cadmium is a cause of breast cancer.
  
  
  METHODS
  We conducted Medline/PubMed and Scopus searches using selected MeSH keywords to identify papers published from January 1, 1980 through January 1, 2013. Data were merged and summary mean differences were estimated using either a random-effects model or a fixed-effects model.
  
  
  RESULTS
  There were 13 studies including 978 exposed cases and 1,279 controls. There was no statistically significant difference in the frequencies of breast cancer between cadmium-exposed and control groups, and the summary estimate of mean difference was 0.71 (95%CI: 0.33-1.08). However, stratification showed that there were statistically significant differences in the frequencies of breast cancer between cadmium-exposed and control groups among Asian compared with Caucasian population, and the summary estimates of mean difference were 1.45 (95%CI: 0.62-2.28) vs. 0.25 (95%CI: -0.09-0.6), respectively. There was a difference in the frequencies of breast cancer between cadmium-exposed and control groups in peripheral venous blood sampling methods, and the summary estimate of mean difference was 1.41 (95%CI: 0.46-2.37).
  
  
  CONCLUSIONS
  Data indicate that the frequencies of breast cancer might be an indicator of early genetic effects for cadmium-exposed populations. However, our meta-analysis was performed on population-based studies; meta-analysis based on individual data might provide more precise and reliable results. Therefore, it is necessary to construct an international database on genetic damage among populations exposed to cadmium that may contain all raw data of studies examining genetic toxicity.
authors.affiliation: Toxicology Research Center, Jundishapur University of Medical Sciences, Ahvaz, Iran. Fakherraheem@yahoo.com
authors.forename: Fakher
authors.initials: F
authors.lastname: Rahim
authors.forename: Amir
authors.initials: A
authors.lastname: Jalali
authors.forename: Raheleh
authors.initials: R
authors.lastname: Tangestani
mesh_terms: D005260:Female; D006801:Humans; D001943:Breast Neoplasms / Q000209:etiology; D002104:Cadmium / Q000009:adverse effects; D016022:Case-Control Studies; D004781:Environmental Exposure / Q000009:adverse effects; D011379:Prognosis; D012307:Risk Factors
chemical_list: D002104:Cadmium