A new method of screening women for genetic risk factors linked to breast cancer could help medical professionals to prevent the development of the condition by detecting the condition early.
The study, carried out by the University of Cambridge and the Institute of Cancer Research in London and published in the Journal of the National Cancer Institute, analysed the genetic codes of over 65,000 women.
Researchers looked at 77 genes which are known to be linked to an increased risk of breast cancer. A 'polygenic risk score' was calculated for each of the 77 genes that were present in a subject's DNA. A significant link between the polygenic risk score and the likelihood of developing breast cancer was found.
Professor Douglas Easton, director of the Centre for Cancer Genetic Epidemiology at the University of Cambridge, said: 'There's still work to be done to determine how tests like this could complement other risk factors, such as age, lifestyle and family history, but it's a major step in the right direction that will hopefully see genetic risk prediction become part of routine breast screening in the years to come.'
The researchers suggested that as tests for breast cancer become more accurate, more tailored therapies for those at greater risk can be provided.
The study found that a women with a polygenic risk score in the top 20% of the group were 1.8 times more likely to develop breast cancer than a normal women, while someone in the top 1% was three times more likely.
Dr Matthew Lam, senior research officer at Breakthrough Breast Cancer, said: 'In recent years we've learned so much about genetic risk factors of breast cancer. What's great to see now is that these findings are starting to be translated into practical methods to predict risk on an individual basis.
The study also found that the polygenic risk score was effective in assessing risk in women both with and without family histories of breast cancer. It showed that the risk of developing breast cancer for women with a history of breast cancer in their family was 24.4% if they were in the top 20% of the polygenic risk score, compared with 8.6% if they were in the bottom 20%. However, for women without a history of breast cancer, the risks were 16.6% and 5.2% respectively.
Nell Barrie, senior science communications manager at Cancer Research UK, said: 'This study shows how the genetic map of breast cancer that scientists have been building up over the years might be used to identify women most at risk, so we can take steps to reduce their chances of developing the disease or catch it at the earliest possible stage.'