title: Perfluorinated compounds are related to breast cancer risk in Greenlandic Inuit: a case control study.
abstract: BACKGROUND
  Breast cancer (BC) is the most common cancer for women in the western world. From very few cases an extraordinary increase in BC was observed in the Inuit population of Greenland and Canada although still lower than in western populations. Previous data suggest that exposure to persistent organic pollutants (POPs) might contribute to the risk of BC. Rat studies showed that perfluorinated compounds (PFCs) cause significantly increase in mammary fibroadenomas. This study aimed at evaluating the association between serum levels of POPs/PFCs in Greenlandic Inuit BC cases and their controls, and whether the combined POP related effect on nuclear hormone receptors affect BC risk.
  
  
  METHODS
  Thirty-one BC cases and 115 controls were sampled during 2000-2003 from various Greenlandic districts. The serum levels of POPs, PFCs, some metals and the combined serum POP related effect on estrogen- (ER), androgen- (AR) and Ah-receptor (AhR) transactivity were determined. Independent student t-test was used to compare the differences and the odds ratios were estimated by unconditional logistic regression models.
  
  
  RESULTS
  We observed for the very first time a significant association between serum PFC levels and the risk of BC. The BC cases also showed a significantly higher concentration of polychlorinated biphenyls at the highest quartile. Also for the combined serum POP induced agonistic AR transactivity significant association to BC risk was found, and cases elicited a higher frequency of samples with significant POP related hormone-like agonistic ER transactivity. The AhR toxic equivalent was lowest in cases.
  
  
  CONCLUSIONS
  The level of serum POPs, particularly PFCs, might be risk factors in the development of BC in Inuit. Hormone disruption by the combined serum POP related xenoestrogenic and xenoandrogenic activities may contribute to the risk of developing breast cancer in Inuit. Further investigations are needed to document these study conclusions.
authors: Centre for Arctic Environmental Medicine, Department of Public Health, Aarhus University, Denmark. ebj@mil.au.dk
authors: Eva C
authors: EC
authors: Bonefeld-Jorgensen
authors: Manhai
authors: M
authors: Long
authors: Rossana
authors: R
authors: Bossi
authors: Pierre
authors: P
authors: Ayotte
authors: Gert
authors: G
authors: Asmund
authors: Tanja
authors: T
authors: Krüger
authors: Mandana
authors: M
authors: Ghisari
authors: Gert
authors: G
authors: Mulvad
authors: Peder
authors: P
authors: Kern
authors: Peter
authors: P
authors: Nzulumiki
authors: Eric
authors: E
authors: Dewailly
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000097:blood / Q000139:chemically induced* / Q000453:epidemiology*; D016022:Case-Control Studies; D004785:Environmental Pollutants / Q000097:blood / Q000633:toxicity*; D005260:Female; D005466:Fluorocarbons / Q000097:blood / Q000633:toxicity*; D006116:Greenland / Q000453:epidemiology; D006801:Humans; D004930:Inuit; D008670:Metals / Q000097:blood / Q000633:toxicity*; D008875:Middle Aged; D011944:Receptors, Androgen / Q000187:drug effects / Q000378:metabolism; D018336:Receptors, Aryl Hydrocarbon / Q000187:drug effects / Q000378:metabolism; D011960:Receptors, Estrogen / Q000187:drug effects / Q000378:metabolism; D012306:Risk
chemical_list: D004785:Environmental Pollutants; D005466:Fluorocarbons; D008670:Metals; D011944:Receptors, Androgen; D018336:Receptors, Aryl Hydrocarbon; D011960:Receptors, Estrogen