Breast cancer gene testing in the US rose after Angelina Jolie announcement
But while more women had the genetic test, a similar increase was not seen in women having surgical procedures to potentially prevent breast cancer (mastectomies), according to the Harvard Medical School study published in The BMJ.
In 2013, Jolie had a double mastectomy after genetic testing revealed she had a faulty version of the BRCA1 gene, which increases the risk of developing breast cancer.
Her article urged women to consider genetic testing, and is one of the most viewed health-related reports in the social media age.
Breast cancer is the most common cancer in the UK with 1 in 8 women diagnosed during their lifetime. But only a very small number of breast cancers are linked to inheriting a faulty BRCA gene.
Jasmine Just, health information officer at Cancer Research UK, said the study shows the influence celebrities can have on people's understanding of cancer and ways to help prevent the disease.
“But while there was an increase in tests for the faulty BRCA gene after the announcement, the proportion of women who went on to have a mastectomy after having the test fell,” she added.
According to the Harvard report, daily BRCA test rates increased sharply in the US after Jolie’s article was published.
Rates rose from 0.71 tests per 100,000 women in the 15 working days before publication, to 1.13 tests in the 15 working days after.
But there was no overall increase in mastectomy rates, with an average of 7 mastectomies a month per 100,000 women from January to December 2013.
And among women who had BRCA tests, the number having mastectomies decreased from around 10 in 100 (10%) during January to April 2013 to 7 in 100 (7%) during May to December 2013.
“The results suggest the extra tests didn't result in finding more women at a higher risk and who therefore could benefit from preventive surgery,” added Just.
“So while celebrities can help reach a lot of people, they may not necessarily reach the group of people who most need the information.”
For those women at higher risk of breast cancer based on family history, and who are considering genetic testing, the advice is to speak with a health professional about the potential risks, benefits and what the results of a test might mean.