Hormone Replacement Therapy & Breast Cancer

Grant #: 2R01CA080888-06A1
PI Name: Carney, Patricia A
Title: Hormone Replacement Therapy And Breast Cancer
Institute: Dartmouth College
Funding Started: 3/1/2000

The overarching goal of this proposal is to improve women's health through enhanced understanding of the role of prescription and over-the-counter postmenopausal hormone therapy use and obesity on breast cancer screening, breast cancer risk, and health-related quality of life. Recent publications from the Women's Health Initiative (WHI) Study confirmed earlier observational study findings showing that use of combined (estrogen + progesterone) hormone therapy regimens increases risk of invasive breast cancer1|2.

Although use of hormone therapies declined after the WHI report, millions of women continue to use them, including 2.5 million U.S. women who specifically use the combined regimen. Preliminary results from an ongoing prospective cohort study, involving 30,488 New Hampshire (NH) women, indicate that use of prescription hormone therapies (HI) has not declined as precipitously as anticipated, while use of over-the-counter hormone therapies have increased post-WHI compared to pre-WHI. The proposed continuation study capitalizes on the established longitudinal cohort and related mammography and breast pathology registries. Its Specific Aims are: 1) To characterize post-WHI longitudinal trends in use of both prescription and over-the-counter hormone therapies, and to identify factors influencing women's use; 2) To determine what factors influence women's adherence to mammography screening, including obesity and use of prescription and over-the-counter hormone therapies before and after the release of WHI findings; 3) To assess the impact of over-the-counter hormone therapies and other factors, such as obesity, on false positive recall and use of associated services in women undergoing mammography screening; 4) To characterize the longitudinal relationships of body mass index (BMI) and hormone therapy on breast cancer risk, with a focus on the influence of BMI changes occurring with menopause transition and/or transitions in hormone therapy (HT) use. As more women consider terminating hormone replacement therapy and initiating use of other postmenopausal therapies (e.g., over-the-counter hormones, raloxifene) to alleviate menopausal symptoms, it is important to document the impact of these agents on health-related quality of life. Therefore, a secondary aim is: 5) To assess the impact of changes in prescription and over-the-counter hormone therapy use on health-related quality of life among women in the community. It is imperative that we understand the impact of both prescription and over-the-counter hormone therapies on screening behavior, the need for additional imaging or interventional work-up to detect breast cancer, breast cancer incidence, and health-related quality of life. Obesity, which is clearly on the rise, is another important factor that must be addressed, especially since it is potentially modifiable.