Genetic research finds 15 new breast cancer hotspots

Genetic research finds 15 new breast cancer hotspots

Researchers involved in the study*, published in Nature Genetics, said that about five per cent of women in the UK carry enough of these ‘hotspots’ to give them about a one-in-four lifetime risk of developing breast cancer. They said their discovery could allow screening and prevention to be targeted at high-risk women.

An international team of researchers in the Breast Cancer Association Consortium, supported in part by Cancer Research UK, studied the genetic make-up of more than 120,000 women of European ancestry, both with and without breast cancer. They identified 15 new single nucleotide polymorphisms (SNPs) associated with an increased risk of breast cancer, bringing to over 90 the total number of SNPs found to be associated with an increase in risk.

Each SNP may increase a women’s breast cancer risk only a little, but some women have enough of the genetic variations to give them, cumulatively, a significant excess risk. In the UK, the mean lifetime risk of breast cancer for a woman is about one in eight. The team calculated that about five per cent of UK women have enough genetic variations to give them double that, about a one-in-four lifetime risk of breast cancer. And a few women, only about 0.7%, have enough of these variations to give them a roughly one-in-three lifetime risk.

The researchers said they hoped that knowing about these genetic markers would enable identification of those women at greatest risk of breast cancer, and could also enable improved cancer screening and prevention.

They said: “Our study is another step towards untangling the breast cancer puzzle. 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.”

Cancer Research UK’s senior science communications manager Nell Barrie added: “This latest study adds more detail to our genetic map of breast cancer risk and could help to develop new ways to identify women most at risk so we can spot breast cancer earlier in the future.”

* Michailidou K, et al. Genome-wide association analysis of more than 120,000 individuals identifies 15 new susceptibility loci for breast cancer. Nature Genetics, 2015. doi:10.1038/ng.3242

By Louise Prime,

OnMedica, Tuesday 10 March 2015

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