Scientists Develop Blood Test Capable of Predicting Breast Cancer Nine Years Before It Strikes

A team of scientists from Imperial College London and the Human Genetics Foundation (HuGeF) in Torino, Italy, may have found a way to predict breast cancer years into the future based on certain DNA markers in the blood according to the Daily Mail.

The team found that DNA methylation levels in blood cells are associated with breast cancer risk, and that this blood marker could be used to identify women at high risk of developing the disease nine years later. The findings could be used to help at-risk women to benefit from preventative treatments such as tamoxifen and raloxifene, according to Breast Cancer Now, a co-funder of the research work.

DNA methylation is the process by which methyl groups are added to the DNA, modifying its function and regulating how much of a gene gets made into proteins, something that is essential for normal cell development. The team's findings confirm 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.

For purposes of the study, the research team took and analyzed blood samples from around 2,600 healthy women from the UK, Norway, Australia and Italy who were then monitored for an average period of nine years.

The women who developed breast cancer during the period were found to have had a lower level of DNA methylation in their white blood cells when compared with those who did not.

The findings confirm DNA methylation as a new player in the field of epigenetics and in the understanding of breast cancer risk, now to be included among the known genetic variants associated with an increased risk of the disease. 

While it is not yet known why the methylation patterns observed in blood cell DNA are linked to breast cancer risk, Breast Cancer Now said "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."

In terms of practical application, Daily Mail suggests that a routine test can be developed based on the research findings. Since it can predict well into the future, the blood test will allow doctors to recommend lifestyle changes that could potentially halt the disease from even developing.

As Dr James Flanagan, from the Department of Surgery and Cancer at Imperial College London, said: "This... has the potential to show how lifestyle and environmental factors influence one's risk of developing breast cancer. Crucially, epigenetic patterns are modifiable, meaning that, unlike genetic risk, there is a possibility that we may find ways in which you can modify your epigenetic risk, so that fewer people develop cancer in the first place."

For one, the levels of methyl chemical in the body can be affected by external factors like alcohol intake which one can control.