MMC/VICC Partnership : Research
Vitamin D and Mammographic Breast Density in African American Women
CO-LEADERS
- Meharry Co-leader
Alecia Malin Fair, Dr.PH. - Assistant Professor of Surgery
AMalin@MMC.edu - Vanderbilt Co-leader
William Dupont, PhD – Professor of Biostatistics
William.Dupont@Vanderbilt.edu
We are planning to study whether nutritional and lifestyle factors correlate with a specific mammographic finding – ‘breast density’ – which has been linked to breast cancer risk, independent of breast size, body mass index (BMI) and other risk factors. Although this relationship is well established overall, there is limited data on its contribution in African American women. Our plan for this pilot study is to enroll approximately 550 women (60% African American) undergoing screening mammography at Nashville General Hospital over a 30 month period. Information on reproductive factors, as well as diet and lifestyle will be collected, as will serum and DNA. The study will be based on standard mammograms performed in the Nashville General clinic. Films will be digitized and read for density using validated methods. The specific hypothesis to be tested in this pilot project is that low serum vitamin D is associated with breast cancer by increasing density of breast tissue. Vitamin D deficiency is emerging as a potentially important modifiable risk factor in breast carcinogenesis. Limited data suggest that inadequate exposure to vitamin D may be associated with increased breast density. However, at this juncture, virtually no data exist on this relationship in African Americans, a population at high risk for both vitamin D deficiency and breast cancer. In this U54-sponsored project, we are proposing to build a resource that can be used to examine hypotheses relevant to breast density in African Americans, a population underrepresented in breast cancer prevention research. The main objective of this project is to examine whether vitamin D, as measured in the serum, is effective in discriminating women with high and low-risk breasts on the basis and mammographic findings including the ratio of stromal and glandular tissue to fat (breast density) which is a strong breast cancer risk factor. A secondary aim of the project is to examine whether polymorphic variation in genes critical to vitamin D signaling (VDR and RXR), or that play a central role in the synthesis (CYP27B1), and catabolism (CYP24A1), and therefore bioavailability of 25(OH)D3, considered the best marker of vitamin D status, are associated with degree of breast density, and other markers of risk. The proposed project will fulfill goals set forth in the U54 in two important ways. First, conduct of the study at Meharry Medical College (MMC) will help build infrastructure that should facilitate future MMC-based epidemiologic investigations. Second, this U54-supported pilot project will contribute important data on a potentially modifiable breast cancer risk factor that disproportionately affects African American women. The project will build critical infrastructure and contribute new knowledge on an important but still poorly understood risk factor in breast cancer.
