A strand of DNA

Study improves accuracy of breast cancer genetic tests for women of different ethnicities

A team of researchers from Manchester University NHS Foundation Trust and the University of Manchester have “developed a way to improve the accuracy of breast cancer genetic testing for women from Ashkenazi Jewish backgrounds.”

The study, funded by Cancer Research UK, forms part of a wider Manchester-based project which seeks to develop accurate tests for women of different ethnicities.

The University of Manchester describes how current Polygenic Risk Scores (PRS) – used to inform women whether they are at low, average or high risk of breast cancer in the next 10 years – are developed from large-scale genome studies using genetic data predominantly collected from mainstream white European populations. As a result, test accuracy depends on how closely an individual’s genetic material resembles the material found in the data.

Through the new study, researchers compared two available PRS and analysed their accuracy for women of Ashkenazi Jewish ancestry. The study found that the PRS tests “inaccurately predicted Ashkenazi Jewish women to be at a higher risk of developing breast cancer”.

By using genetic information from Ashkenazi Jewish women, obtained from a Manchester regional genetics database and the Breast Cancer in Northern Israel study, the researchers were able to adjust the test to generate a more accurate prediction.

Professor Gareth Evans, leading the research, commented: “A test result which exaggerates a woman’s risk of the disease could lead to undue stress or concern and unnecessary screening and preventative measures that they don’t need. Future PRS for Ashkenazi Jewish women should be based on their genetic data to provide a more accurate risk prediction.

“This study is an important step forward in our continued research into breast cancer genetic testing for people of different ethnic backgrounds to improve equity. More accurate and personalised PRS are required to avoid further increasing health inequalities and so patients can receive high-quality screening, care, and treatments.”

The study was supported by the National Institute for Health and Care Research Manchester Biomedical Research Centre.