| DDT and Breast Cancer in Young Women: New Data on the Significance of Age at Exposure Barbara A. Cohn,1 Mary S. Wolff,2 Piera M. Cirillo,1 and Robert I. Sholtz1 1Child Health and Development Studies, Center for Research on Women's and Children's Health, Public Health Institute, Berkeley, California, USA; 2Mount Sinai School of Medicine, New York, New York, USA Abstract
Background: Previous studies of DDT and breast cancer assessed exposure later in life when the breast may not have been vulnerable, after most DDT had been eliminated, and after DDT had been banned. Objectives: We investigated whether DDT exposure in young women during the period of peak DDT use predicts breast cancer. Methods: We conducted a prospective, nested case–control study with a median time to diagnosis of 17 years using blood samples obtained from young women during 1959–1967. Subjects were members of the Child Health and Development Studies, Oakland, California, who provided blood samples 1–3 days after giving birth (mean age, 26 years) . Cases (n = 129) developed breast cancer before the age of 50 years. Controls (n = 129) were matched to cases on birth year. Serum was assayed for p,p´-DDT, the active ingredient of DDT ; o,p´-DDT, a low concentration contaminant ; and p,p´-DDE, the most abundant p,p´-DDT metabolite. Results: High levels of serum p,p´-DDT predicted a statistically significant 5-fold increased risk of breast cancer among women who were born after 1931. These women were under 14 years of age in 1945, when DDT came into widespread use, and mostly under 20 years as DDT use peaked. Women who were not exposed to p,p´-DDT before 14 years of age showed no association between p,p´-DDT and breast cancer (p = 0.02 for difference by age) . Conclusions: Exposure to p,p´-DDT early in life may increase breast cancer risk. Many U.S. women heavily exposed to DDT in childhood have not yet reached 50 years of age. The public health significance of DDT exposure in early life may be large. Key words: breast cancer, child health and development studies, exposure timing, o, p´-DDT, organochlorines, p, p´-DDE, p, p´-DDT, pregnancy, premenopausal. Environ Health Perspect 115:1406–1414 (2007) . doi:10.1289/ehp.10260 available via http://dx.doi.org/ [Online 24 July 2007]
Address correspondence to B.A. Cohn, Child Health and Development Studies, 1683 Shattuck Ave., Suite B, Berkeley, CA 94709 USA. Telephone: (510) 649-6390. Fax: (510) 843-0747. E-mail: bcohn@chdstudies.org We acknowledge the late J. Yerushalmy, who founded the Child Health and Development Studies ; B.J. van den Berg, R.E. Christianson, R.D. Cohen, and the late F. Oechsli for advice on design ; N. Rifai for lipid assays ; P. Siiteri for reviewing and commenting on earlier versions of this manuscript and noting the relevance of early studies of radiation effects on breast cancer ; and the California Cancer Registry staff for high-quality cancer surveillance that made this study possible. This research was supported by the National Cancer Institute (grant R01 CA72919) and the National Institute for Child Health and Development (grants N01 HD 6 3258 and N01 HD 1 3334 ) . The authors declare they have no competing financial interests. Received 13 March 2007 ; accepted 23 July 2007.
Correction In the original manuscript published online, a data point for New York City in 1986 was inadvertently omitted from Figure 1B. It has been corrected here.
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