Organochlorine exposure and breast cancer survival

Recent research suggests that exposure to organochlorines, such as dieldrin that possess estrogenic properties, may increase the risk of breast cancer by promoting growth of malignant cells. Whether this potential also affect s malignant cells not eradicated by treatment, and thereby survival, is unk nown. To evaluate this blood samples from female participants in the Copenh agen City Heart Study, Denmark, were analyzed for organochlorines. A total of 195 breast cancer cases, who each provided two blood samples that were t aken in 1976-78 and 1981-83, respectively, were included in the survival an alysis. Dieldrin had a significant adverse effect on overall survival and b reast cancer specific survival (RR, 2.78, 95% CI, 1.38-5.59, P trend < 0.01 ; RR, 2.61, 95% CI, 0.97-7.01, P trend < 0.01). This association was streng thened when exposure was assessed as the average serum concentration of the two measurements. These findings suggest that past exposure to estrogenic organochlorines such as dieldrin may not only affect the risk of developing breast cancer but also the survival. (C) 2000 Elsevier Science Inc. All ri ghts reserved.