DDT (DICOPHANE) AND POSTMENOPAUSAL BREAST-CANCER IN EUROPE - CASE-CONTROL STUDY

Objective: To examine any possible links between exposure to DDE (1,1- dichIoro-2,2-bis(p-chlorophenyl)ethylene), the persistent metabolite o f the pesticide dicophane (DDT), and breast cancer. Design: Multicentr e study of exposure to DDE by measurement of adipose tissue aspirated from the buttocks. Laboratory measurements were conducted in a single Laboratory. Additional data on risk factors for breast cancer were obt ained by standard questionnaires. Setting: Centres in Germany, the Net herlands, Northern Ireland, Switzerland, and Spain. Subjects: 265 post menopausal women with breast cancer and 341 controls matched for age a nd centre. Main outcome measure: Adipose DDE concentrations. Results: Women with breast cancer had adipose DDE concentrations 9.2% lower tha n control women. No increased risk of breast cancer was found at highe r concentrations. The odds ratio of breast cancer, adjusted for age an d centre, for the highest versus the lowest fourth of DDE distribution was 0.73 (95% confidence interval 0.44 to 1.21) and decreased to 0.48 (0.25 to 0.95; P for trend = 0.02) after adjustment for body mass ind ex, age at first birth, and current alcohol drinking. Adjustment for o ther risk factors did not materially affect these estimates. Conclusio ns: The lower DDE concentrations observed among the women with breast cancer may be secondary to disease inception. This study does not supp ort the hypothesis that DDE increases risk of breast cancer in postmen opausal women in Europe.