DNA tests for breast cancer gene mutation affecting Ashkenazi Jews can lead to unnecessary surgery

Scientists at the University of Exeter analysed the data of more than 450,000 people aged between 40 and 69 and found that carrying a disease-causing BRCA variant was linked to a breast cancer risk of 18 per cent for the BRCA2 gene and 23 per cent for BRCA1 by age 60.

When a close relative has had the condition that risk rises to 24 per cent and 45 per cent respectively, according to the research, published in eClinical Medicine, an open access clinical journal, published by The Lancet.

Women informed outside a clinical setting that they carry a disease-causing BRCA variant may be told that their risk of breast cancer is as high as 80 per cent, it said.

In recent years, more women with a faulty BRCA gene have chosen to have surgery, particularly since actress Angelina Jolie (inset) shared her family history of the disease and subsequent genetic test and surgery, the study’s lead author, Dr Leigh Jackson, noted.

But he said: “Being told you are at high genetic risk of disease can really influence levels of fear of a particular condition and the resulting action you may take.

“Up to 80 per cent risk of developing breast cancer is very different from 20 per cent. That difference could well influence the decision you make around whether you have invasive breast surgery… we want [patients] to make an informed decision.”

The research team urged anyone communicating cancer risk to do so “based on a detailed family history, not just genetics alone”.