Oxychlordane and trans-nonachlor in breast adipose tissue and risk of female breast cancer

J Epidemiol Biostat. 2000;5(3):153-60.


Background: Organochlorine compounds, including organochlorine pesticides, have been suggested by some, but not all, studies to be associated with female breast-cancer risk. So far, studies relating organochlorine compounds and breast-cancer risk have mainly focused on polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) as risk factors for female breast cancer. This paper examines the hypothesis that environmental exposure to trans-nonachlor (TNC) and oxychlordane (OCD), a major metabolite of the insecticide chlordane, increases the

Methods: A total of 304 histologically confirmed, incident primary breast-cancer patients and 186 histologically confirmed incident benign breast-disease controls were included in the study between 1994 and 1997. Breast adipose tissue not needed for diagnostic purposes was collected and analysed for TNC, OCD and other organochlorine compounds. A standardised, structured questionnaire was used to obtain information on major known, or suspected, risk factors for breast cancer.

Results: The age and lipid-adjusted geometric mean adipose-tissue levels of OCD were similar between the cases [36.4 p.p.b., 95% confidence interval (CI) 34.7-38.2 p.p.b.] and controls (38.0 p.p.b., 95% Cl 35.7-40.6 p.p.b.). The age and lipid-adjusted geometric mean adipose-tissue levels of TNC between the cases (55.5 p.p.b., 95% CI 52.6-58.5 p.p.b.) and controls (58.1 p.p.b., 95% CI 54.2-62.3 p.p.b.) were also similar. There was no association between breast-cancer risk and mean adipose-tissue levels of OCD and TNC. The covariate-adjusted odds ratio (OR) was 0.7 (95% CI 0.4-1.3) for OCD and 1.1 (95% CI 0.6-1.9) for TNC, when the highest quartile was compared with the lowest. The risk also did not vary based on oestrogen or progesterone receptor status or menopausal status.

Discussion: We found no significantly increased risk of breast cancer associated with breast adipose-tissue levels of OCD or TNC; this is consistent with recent epidemiological studies, indicating that environmental exposure to organochlorine compounds does not have an overall significant impact on breast-cancer risk.

Publication types

  • Comparative Study

MeSH terms

  • Adipose Tissue / chemistry
  • Adipose Tissue / metabolism*
  • Adult
  • Aged
  • Breast / chemistry
  • Breast / metabolism*
  • Breast Neoplasms / chemically induced
  • Breast Neoplasms / metabolism*
  • Case-Control Studies
  • Chlordan / analogs & derivatives*
  • Chlordan / analysis
  • Chlordan / pharmacokinetics
  • Chromatography, Gas / methods
  • Chromatography, Gas / statistics & numerical data
  • Female
  • Heptachlor / analysis
  • Heptachlor / pharmacokinetics*
  • Humans
  • Insecticides / analysis
  • Insecticides / pharmacokinetics*
  • Logistic Models
  • Middle Aged
  • Risk Factors


  • Insecticides
  • Chlordan
  • oxychlordane
  • Heptachlor