Approved research

Interplay between lifestyle factors, genetics and risk of breast cancer among UK women

Lay summary

Breast cancer significantly affects the lives of women globally. Studies have shown that having a family history of breast cancer is strongly associated with increased risk of this cancer; thus supporting a role for genes in its development. Lifestyle-related factors such as obesity, physical inactivity, diets high in fats and certain types of sugars but low in fibre and vitamins and minerals, moderate to high alcohol intake and probably smoking have also been associated with increased risk of breast cancer. Breast cancer development is thought to involve an interaction between these genetic and lifestyle factors. However, to date, most observational studies have not demonstrated interactions between these factors. This may be because these studies have explored the interaction between individual genes and individual lifestyle-related risk factors with risk of breast cancer. The interaction between a combined genetic score and a combined lifestyle score and risk of breast cancer may have a greater effect on risk of breast cancer than the interaction between individual genes or lifestyle components. Hence, this study aims to investigate how an overall healthy lifestyle modifies the association of a combination of genes with risk of breast cancer using data from the UK Biobank. We will include female participants with available genetic and lifestyle information measurements who developed breast cancer. We will use statistical methods to estimate how the association of a genetic score and risk of breast cancer is modified by adherence to a healthy lifestyle. This study will provide important information for prevention strategies aimed to towards reducing risk of breast cancer, particularly among women who have a high risk of breast cancer. It will also be useful for risk stratification.