Valerie McCormack works at the London School of Hygiene and Tropical Medicine, investigating how lifestyle choices affect breast density in women from different ethnic groups.
Breasts are made up of different types of tissue. Dense breasts contain more fibrous and glandular tissue whereas less dense breasts contain more fat. Women with a greater proportion of dense tissue have an increased risk of breast cancer, possibly because breast cancer tends to originate in glandular tissue.
In the 1990s, Cancer Research UK scientists helped demonstrate that women with dense breasts have a higher risk of breast cancer.
But we don't know why some women have denser breasts than others. It could be due to their genes, or their lifestyle, or a combination of both. Understanding more about the links between lifestyle, breast density and breast cancer risk could help to identify ways of reducing a woman’s chance of developing the disease.
Scientists have known for some time that women from South Asia who live in the UK are less likely to develop breast cancer than women born here. But, again, it is unclear how much of this difference is due to lifestyle, and how much is down to genetics.
Miss McCormack's study is the first to look at breast density in different ethnic groups, to better understand the links between all these factors. She is recruiting 700 White, African Caribbean and South Asian post-menopausal women who attend the NHS Central and East London Breast Screening Service for routine breast cancer screening.
She will work out their breast density from mammograms and record information about their lifestyles, including family history, diet, alcohol intake, weight and use of oral contraceptives.
From this, she should be able to work out if these affect a woman's breast density, and if this varies between different ethnic groups.
Breast cancer is the most common cancer in women in the UK. This study will tell us more about the causes of this common disease, and hopefully give us clues about how to prevent it.