Prospects for blood test to predict breast cancer risk

3 July 2014

A novel epigenetic signature (likened to a ‘switch’ to activate or deactivate genes) could form the basis of a blood test for breast cancer risk.

First identified in women with BRCA1 mutations associated with familial breast-ovarian cancer syndrome, the DNA methylation (DNAme) signature was associated with increased risk of developing cancer and poorer prognosis.

New research published in Genome Medicine found the same epigenetic signature in women without BRCA1 mutations and tested it in two independent groups comprising a total of 138 post-menopausal women who went on to develop breast cancer and 199who remained cancer-free. Importantly, it was found to act as a good early predictor breast cancer risk, raising the prospect of developing an early screening test for breast cancer risk via blood samples.

Lead UCL researcher Professor Martin Widschwendter said: "The data is encouraging since it shows the potential of a blood-based epigenetic test to identify breast cancer risk in women without known predisposing genetic mutations".

It is not yet known how well such a test, once enhanced for clinical application, would perform in the general population, nor what proportion of women at significantly increased genetic risk of cancer unrelated to BRCA1/2 mutations it may account for. However, the prospects for personalised or stratified cancer screening incorporating genetic risk information alongside traditional measures (such as age or sex) to improve accuracy are generally very good.

Dr Matthew Lam of the Breakthrough Breast Cancer charity commented: "DNA signatures such as this have the potential to add an extra layer of accuracy in the way we are able to assess a woman's individual risk of breast".

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