Addressing Health Inequalities – Improving breast cancer genetic testing for diverse communities
Women’s risk of developing breast cancer is heavily influenced by their genes. Researchers have found that we all carry tiny genetic variations, called Single Nucleotide Polymorphisms (SNPs), which increase or decrease our risk of disease, depending on our unique combination of these.
New forms of genetic tests, which look for these SNPs, are becoming more widely available to women, both privately through commercial companies and through research studies on the NHS breast screening programme.
Researchers are also exploring how genetic information from these tests can be combined with information about women’s lifestyle, and family and reproductive history, to produce a Polygenic Risk Score (PRS) – which can inform women whether they are at low, average, or high risk of developing breast cancer in the next 10 years.
Currently, the genetics data used to create PRS has predominately come from white European women. While the tests can accurately predict breast cancer risk for these women, researchers from our Cancer Prevention and Early Detection Theme found that they were not accurate for women from Black, Asian, mixed-race and Ashkenazi Jewish backgrounds, and often over-estimated risk in these groups.
Our researchers are now working to recruit more women from Black, Asian, mixed-race and Ashkenazi Jewish backgrounds to research studies, so that they can develop specific PRS for these backgrounds and reduce inequalities in testing.
They have also called on commercial companies to make it clear which ethnicities their PRS test have been developed for, and that national breast screening programmes should take this into account when adopting these tests.
A researcher perspective:
These findings show you can’t simply apply polygenic risk scores (PRS) derived from White Europeans in people of other ethnicities. Black, Asian, mixed-race and Jewish women in the UK might buy commercial tests that could exaggerate their risk of the disease. This may frighten them and lead to unnecessary screening and other interventions they don’t need. “There is an urgent need for more research to develop ways of adjusting these risk scores for different ethnicities. We need more accurate risk predictions to avoid further increasing existing health disparities in minority populations in the UK.
Professor Gareth Evans
Theme Lead, NIHR Manchester BRC Cancer Prevention and Early Detection Theme
A participant perspective:
My mum was diagnosed with stage 3 breast cancer at 36-years-old and died when she was 47-years-old. Testing early is important as breast cancer can affect whole families and both me and my sister have been told we’re at very high risk of the disease and will need extra mammograms to monitor this when we reach our thirties. “Though we grew up in France, my family are from an Arab background originally from Lebanon. There needs to be more research conducted to ensure these genetics tests are more accurate for people of different ethnic backgrounds, as it’s clear you can’t just apply them to everyone.