DNA discovery points to new clinical biomarker in predicting breast cancer risk

Scientists have identified a new biomarker in the blood that could help identify more women at an increased risk of breast cancer. Such women might benefit from risk-reducing measures.

In a prospective study, researchers from Imperial College London and the Human Genetics Foundation (HuGeF) in Torino, Italy, have concluded that DNA methylation levels in blood cells are associated with breast cancer risk, and could be used to identify women at increased risk of developing the disease.

DNA methylation is the process by which methyl groups are added to the DNA, modifying its function and regulating how much of a gene’s protein product gets made, something that is essential for normal cell development. The team’s findings build on a growing body of evidence suggesting that lower than normal methylation of white blood cell DNA could be predictive of a heightened breast cancer risk.

The studies analysed by the researchers took blood samples from healthy women who were then monitored for an average period of around nine years. The women who developed breast cancer during this time had a lower level of DNA methylation in their white blood cells, compared to the women who didn’t develop the disease.

The research highlights DNA methylation as a key player in our understanding of breast cancer risk – adding to a growing list of known genetic variants associated with an increased risk of the disease – which will ultimately help us refine and improve the ways we assess, and monitor, an individual’s breast cancer risk.

Whilst this research is at a very early stage, it is hoped that one day scientists could potentially be able to proactively change methylation patterns, underlining the importance of research into epigenetics.

Further studies will now be required to understand why the methylation patterns observed in blood cell DNA are linked to breast cancer risk, as this is not currently known. It is hoped that women already known to be at increased risk of developing the disease could be given a blood test to assess and monitor methylation levels in order to better understand their risk and inform decisions around preventative treatments. Imperial College London