The Molecular Epidemiology of Breast Cancer: Risk from Environmental Exposures and Genetic Susceptibility

Abstract : This postdoctoral research fellowship included a thorough investigation of genetic and environmental determinants of breast cancer risk. Major findings from this research include the following: (1) smoking may be an important risk factor for breast cancer among postmenopausal women with genetically-determined slow acetylation phenotype; (2) the null GSTM1 genotype may be associated with breast cancer risk among premenopausal smokers, but is not an overall risk factor for breast cancer; (3) the CYP1A1 variant genotype is not a strong risk factor for breast cancer, but may be associated with greater risk among smokers; (4) consumption of processed meats, high sources of known mammary mutagens, may increase risk for premenopausal breast cancer, particularly among women with rapid NAT2 genotype; (5) the CYP2E1 variant genotype is not associated with risk, but may be a risk factor for premenopausal smokers; (6) higher serum organochlorine levels were not associated with greater risk of postmenopausal breast cancer; (7) higher serum levels of PCBs were associated with increased risk of breast cancer among parous women who never lactated; and (8) the CYP1A1 variant genotype was a risk factor for women with high PCB body burden. Methodological issues concerning the investigation of organochlorine compounds in epidemiologic studies were explored.