Breast cancer is the most common cancer in Australian women and is highly heritable. Mammographic density is one of the strongest predictors of breast cancer risk and is also highly heritable.
Mammographic density is the white area on a mammogram representing the radiographic appearance of epithelial and stromal tissue (as opposed to fatty tissue which appears dark on a mammogram). It cannot be determined by feel or touch. Women with extensive mammographic density are 4-6 times more likely to develop breast cancer than women of similar age with little or no mammographic density.
Identifying genetic variants associated with mammographic density will not only increase our understanding of the biological pathways involved in the development of breast cancer, but as mammographic density is also a modifiable risk factor, genetic variants associated with mammographic density could be used to identify and target women at high risk of the disease.
The proposed project will provide us with initial evidence of the genomic locations of mammographic density-related quantitative trait loci (QTL) by exploiting large pedigrees nested within the Busselton Health Study and utilizing linked data from BreastScreen WA (mammograms and breast cancer risk factor data), the WA Cancer Registry (breast cancer incidence and pathology variables), and the Death Registry (date and cause of death) via the Western Australia Data Linkage System.
The specific aims of this project are:
- To link a selected sample of participants from the Busselton Health Study with BreastScreen WA and the Department of Health WA Data Linkage Unit to identify who has attended mammographic screening, who has developed breast cancer, and who has died from the disease.
- To obtain the mammograms from participants from above Aim 1 and measure mammographic density using computer-assisted software at the University of Western Australia.
- To identify genomic locations of rare loci associated with mammographic density, one of the strongest predictors of breast cancer risk, using existing genome wide association (GWA) data and novel statistical methods.
This project is a collaborative effort between GOHaD and BreastScreen WA:
This work is pivotal to obtain future funding for a much larger project that would involve sequencing the genomic areas of interest identified in the proposed project in high-risk families to find genetic variants associated with mammographic density. Before we can do this we need to demonstrate that these large, informative families exist (via the proposed project).
For more information, contact Jennifer Stone.
This work has been supported by the Breast Cancer Research Centre WA