title: Selenium in breast cancer.
abstract: OBJECTIVE
  Controversy surrounds the hypothetical relationship between low serum levels of selenium and reduced activity of selenium-dependent enzymes, such as glutathione peroxidase, and an increased risk of cancer in humans. This study investigated serum concentrations of selenium in women with and without breast cancer.
  
  
  METHODS
  In this case-control study, we compared serum concentrations of selenium in women with breast cancer (n = 200), healthy women (n = 100), and women with chronic diseases (n = 100). Patients with breast cancer were divided into premenopausal (n = 99) and postmenopausal subjects (n = 101).
  
  
  RESULTS
  Mean serum concentrations of selenium were 81.1 microg/l in women with breast cancer and 98.5 microg/l in women with non-tumoral disease (p < 0.001).
  
  
  CONCLUSIONS
  Alterations in serum concentrations of selenium in women with breast cancer appear to be a consequence, rather than a cause of cancer. In accordance with the hypothesis, the findings suggest that very low selenium status could be due to the nature of cancer.
authors.affiliation: Department of Medicine, University of Cadiz School of Medicine, c/Dr. Marañón 6, E-11002 Cadiz, Spain. juanbosco.lopez@uca.es
authors.forename: Juan-Bosco
authors.initials: JB
authors.lastname: Lopez-Saez
authors.forename: Avelino
authors.initials: A
authors.lastname: Senra-Varela
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Pousa-Estevez
mesh_terms: D000208:Acute Disease; D000328:Adult; D000367:Age Factors; D000368:Aged; D001943:Breast Neoplasms / Q000097:blood* / Q000473:pathology; D016022:Case-Control Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D017698:Postmenopause; D017697:Premenopause; D018570:Risk Assessment; D012307:Risk Factors; D012643:Selenium / Q000097:blood*
chemical_list: D012643:Selenium