The overall Women's Health Initiative (WHI) program is intended to address cardiovascular disease, cancers of the breast and colon/rectum, and osteoporosis, the most common causes of death, disability, and impaired quality of life in postmenopausal women. The major components of the WHI are: a randomized controlled clinical trial of postmenopausal Hormone Therapy (HT), Dietary Modification (DM), and Calcium/Vitamin D supplementation (CaD); and a companion observational study (OS). The Clinical Trials and Observational Study components were completed in 2005; the WHI Extension Study continues to follow all consenting participants for health outcomes and selected exposures. This project will perform research to maximize the scientific yield from the biologic resource and associated participant exposure and outcome data in the WHI program. The overall objective is to build on the ongoing WHI-Perlegen Genome Wide Association Study (GWAS) of breast cancer, coronary heart disease (CHD) and stroke. The present project will idenfity breast cancer-related single nucleotide polymorphisms(SNPs) from among the SNPs identified in Phase 1 of the previous GWAS project, and will also look for SNPs that interact with the effects of any of the four WHI clinical trial interventions on breast cancer.
