The 'Angelina effect' has doubled preventative mastectomy numbers in the UK

Jolie's announcement in May 2013 that she had had a double mastectomy caused a media storm. The American actress carries a mutation in the BRCA1 gene, as did her mother, who died of breast cancer. She explained that she decided to have the operation to eliminate the 87% risk that she would one day develop breast cancer.

Her decision led to renewed interest in breast cancer genetic research which a research team at a breast cancer prevention clinic at the University Hospital of South Manchester in the UK decided to investigate.

In their study, which was published in the journal Breast Cancer on November 25, the researchers noted that the number of double mastectomies carried out in their clinic had more than doubled between January 2014 and June 2015, reaching a total of 83 procedures, whereas only 29 preventive mastectomies had been performed there between January 2011 and June 2012.

While they did not question the patients about their underlying reasons for having the operation, professor of clinical genetics Gareth Evans and his team believe that the "Angelina Jolie effect" did much to encourage them.

At the breast cancer prevention clinic at the University Hospital of South Manchester, the number of operations performed on women with BRCA1/2 gene mutations increased from 17 between January 2011 and June 2012, to 31 from January 2014 to June 2015.

The researchers noted that there was even an increase in the number of procedures on high-risk women without the BRCA1/2 gene mutation (up from 12 to 52 over the same period).

The researchers pointed out that there is normally a period of 9 to 12 months between the initial consultation and the operation. This could explain the rise in preventative mastectomies at the beginning of 2014, some 9 months after Angelina Jolie made her announcement.