A simple blood test could soon be made possible to predict those at risk of non-hereditary breast cancer.
Breast cancer can be caused by many factors, including gene mutations which are passed from parents onto their children. For example, the hereditary breast cancer gene, BRCA1, accounts for around 10% of breast cancer cases. The majority of cases however, are caused by factors not yet entirely understood.
But researchers are beginning to make headway. An epigenetic signature has been identified across all women who carry the mutated BRCA1 gene. Strikingly, researchers have found the same signature was discovered in the blood of women without the BRCA1 mutation but who went on to develop breast cancer, making it a potential early marker of women’s cancer in the general population.
Cancer scientists now understand that mutations within genes are not the only contributors to the development of disease. The arrangement and expression of our genes has a major impact, and this is overseen by the process of epigenetics.
One of the most studied epigenetic mechanisms is a process called DNA methylation, which was the focus of this particular study.
Researchers looked at the DNA methylation signature in the blood of women both with and without BRCA1 mutations. When the signature was applied to the samples from both of these groups, the women who had developed non-hereditary cancers were found to have the same DNA methylation signature as those with the hereditary gene.
Professor Martin Widschwendter, the study’s lead author and head of the UCL Department of Women’s Cancer, says: “We identified an epigenetic signature in women with a mutated BRCA1 gene that was linked to increased cancer risk and lower survival rates. Surprisingly, we found the same signature in large cohorts of women without the BRCA1 mutation and it was able to predict breast cancer risk several years before diagnosis.”
Further research is required to find out whether this epigenetic signature is just an indicator of breast cancer risk or is involved in the actual development of breast cancer. Work is now also being undertaken to use these findings in clinical trials.