Dichlorodiphenyldichloroethene, Polychlorinated Biphenyls, and Breast Cancer among African-American and White Women in North Carolina

We examined plasma dichlorodiphenyldichloroethene (DDE) and total polychlorinated biphenyl (PCB) levels in relation to breast cancer in a population-based, case-control study of African-American women (292 cases and 270 controls) and white women (456 cases and 389 controls) in North Carolina. Adjusted odds ratios (ORs) for breast cancer comparing the highest to lowest third of DDE were 1.41 [95% confidence interval (CI), 0.87–2.29] in African-American women and 0.98 (95% CI, 0.67–1.43) in white women. ORs comparing the highest to lowest third of total PCBs were 1.74 (95% CI, 1.00–3.01) in African-American women and 1.03 (95% CI, 0.68–1.56) in white women. Among African-Americans, the OR for total PCBs was highest for obese women (body mass index≥ 34.2; OR, 4.92; 95% CI, 1.63–14.83). In contrast, the OR for DDE was highest for the leanest African-American women (body mass index,