Angelina Jolie’s statement that she had double mastectomy is likely to have had a bigger impact than other celebrity announcements. Photo: Dominic Lipinski/PA Wire

Referrals for genetic breast cancer tests more than doubled in the UK as a result of what doctors have dubbed the ‘Angelina effect’.

In May last year, actress Angelina Jolie revealed to the world that she had undergone a double mastectomy to prevent her getting breast cancer.

She took the decision after testing positive for the BRCA1 gene mutation that greatly increases the risk of developing the disease.

A study has now measured the impact her surprise announcement made on British women.

It shows that in June and July last year the number of British GP referrals for genetic counselling and DNA tests for breast cancer mutations increased two-and-a-half times compared with the same period in 2012.

The effect was long-lasting, with referrals remaining at twice the previous year’s figure from August to October.

But the extra women seeking help were not worried about nothing – most had a family history of breast cancer, meaning they were being appropriately screened.

Gareth Evans, from the charity Genesis Breast Cancer Prevention and St Mary’s Hospital, Manchester, who led the study published in the journal Breast Cancer Research, said: “Angelina Jolie stating she has a BRCA1 mutation and going on to have a risk-reducing mastectomy is likely to have had a bigger impact than other celebrity announcements, possibly due to her image as a glamorous and strong woman.

A study has measured the impact her surprise announcement made on British women

“This may have lessened patients’ fears about a loss of sexual identity post-preventative surgery and encouraged those who had not previously engaged with health services to consider genetic testing.

“These high-profile cases often mean that more women are inclined to contact centres such as Genesis – and other family history clinics – so that they can be tested for the mutation early and take the necessary steps to prevent themselves from developing the disease.

“Of course, in some cases this may mean a risk-reducing mastectomy, however, cancer preventing drugs, such as tamoxifen, and certain lifestyle changes like a healthy diet and more exercise, are also options which many women may consider.”

Defective versions of BRCA1 and its sister gene BRCA2 are together responsible for about a fifth of breast cancers.

Women who inherit BRCA1 have a 60 per cent to 90 per cent risk of developing breast cancer in their lifetime. BRCA2 increases the risk by 45 per cent to 85 per cent.

Both gene mutations also raise the risk of ovarian cancer. The ‘Angelina effect’ highlights the need for more to be done to improve awareness of inherited breast cancer, say the researchers.

Sally Greenbrook, senior policy officer at the charity Breakthrough Breast Cancer, said: “We have heard anecdotally that referrals to family history and genetics services had increased since Angelina Jolie’s announcement but it’s interesting to see evidence to support this.

“We’re also encouraged to learn that women with a family history of breast cancer are recognising that they may be at increased risk of developing the disease and taking a proactive approach to their health.

“It’s important to remember however that only one in five breast cancer cases are linked to having a family history of the disease, and faults in known breast cancer genes are very rare.

“This is why genetic testing is only offered to those considered to be at higher risk following a family history assessment.

“We know that some family history services currently struggle to meet demand.”