Scientists have discovered another 15 genetic ‘hot-spots’ that can increase a woman’s risk of developing breast cancer, according to research published in Nature Genetics (2015; doi:10.1038/ng.3242).
In a study funded by Cancer Research UK, scientists compared tiny variations in the genetic make-up of more than 120,000 women of European ancestry, with and without breast cancer, and identified 15 new variations, known as single nucleotide polymorphisms (SNPs), that are linked to a higher risk of the disease.
This new discovery means that a total of more than 90 SNPs associated with breast cancer have now been revealed through research.
On average, one in every eight women will develop breast cancer at some stage in their lives. The researchers estimate that about 5% of women have enough genetic variations to double their risk of developing breast cancer, giving them a risk of approximately 1 in 4.
A much smaller group of women, approximately 0.7%, have genetic variations that make them three times more likely to develop breast cancer, giving them a risk of approximately 1 in 3. It’s hoped that these genetic markers can be used to help identify high-risk women and could lead to improved cancer screening and prevention.
“Our study is another step towards untangling the breast cancer puzzle,” said study author Professor Doug Easton, PhD, professor of genetic epidemiology at the University of Cambridge in the United Kingdom. “As well as giving us more information about how and why a higher breast cancer risk can be inherited, the genetic markers we found can help us to target screening and cancer prevention measures at those women who need them the most.
“The next bit of solving the puzzle involves research to understand more about how genetic variations work to increase a woman’s risk. And we’re sure there are more of these variations still to be discovered.”
The study was carried out by dozens of scientists across the world working together in the Breast Cancer Association Consortium, part of the Collaborative Oncological Gene-Environment Study. Each of the genetic variations, identified through this study and other research, is known to raise a woman’s risk of breast cancer by a small amount. However, some people have lots of these variations, which add up to a more significantly increased risk.
Breast cancer is the most common type of cancer in the United States, with approximately 290,000 new diagnoses in women every year. Death rates are falling as we learn more about the disease and how to diagnose and treat it.