ORIGINAL CONTRIBUTIONS Plasma Concentrations of Polychlorinated Biphenyls and the Risk of Breast Cancer: A Congener-specific Analysis Alain Demers1, Pierre Ayotte2,3, Jacques Brisson3,4, Sylvie Dodin2,5, Jean Robert4 and Éric Dewailly2,3 1 Department of Preventive Oncology and Epidemiology, CancerCare Manitoba, Winnipeg, Manitoba, Canada. 2 Unité de Recherche en Santé Publique, Centre de Recherche du CHUQ (CHUL), Beauport, Québec, Canada. 3 Département de Médecine Sociale et Préventive, Faculté de Médecine, Université Laval, Ste-Foy, Canada. 4 Unité de Recherche en Santé des Populations et Centre des Maladies du Sein Deschênes-Fabia, Hôpital Saint-Sacrement, Centre Hospitalier Affilié Universitaire de Québec, Québec, Canada. 5 Unité de Recherche en Endocrinologie de la Reproduction, Centre de Recherche du Pavillon Saint-François-d'Assise, Québec, Canada. Some reports indicate that exposure to specific polychlorinated biphenyl (PCB) congeners is related to breast cancer risk. The authors recruited participants in a case-control study from October 1994 to March 1997 to assess the relation between breast cancer risk and concentrations of 14 PCB congeners measured in plasma lipids by high-resolution gas chromatography. Participants were incident cases of breast cancer (n = 314) and controls (n = 523) from the Quebec City region (Canada). Compared with controls, cases had significantly higher concentrations of PCB 99 (p = 0.02), PCB 118 (p = 0.03), and PCB 156 (p = 0.006). Associations were found between breast cancer risk and either PCB 118 (odds ratio (OR) = 1.60, 95% confidence interval (CI): 1.01, 2.53; fourth vs. first quartile) or PCB 156 (OR = 1.80, 95% CI: 1.11, 2.94; fourth vs. first quartile) concentration. Breast cancer risk was also associated with a total concentration of the three mono-ortho-substituted congeners 105, 118, and 156 expressed as 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (OR = 2.02, 95% CI: 1.24, 3.28; fourth vs. first quartile). These results suggest that exposure to dioxin-like PCBs increases breast cancer risk. Alternatively, the results may be explained by differences between cases and controls regarding metabolic pathways involved in the biotransformation of both mono-ortho PCBs and estrogens. Am J Epidemiol 2002;155:629–35. American Journal of Epidemiology Vol. 155, No. 7 : 629-635 Occup & Env Med, 6/03 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.