14 Aralık 2016 Çarşamba

"Angelina Jolie effect" boosted genetic testing rates, study suggests

Angelina Jolie’s revelation that she underwent a double mastectomy to reduce her chances of developing breast cancer boosted rates of genetic testing among women, but might have failed to reach those most at risk, new research suggests.


In a 2013 article for the New York Times, Jolie explained her decision to undergo a double mastectomy after finding that she had a mutation in a gene known as BRCA1 that greatly increased her risk of breast and ovarian cancers.


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“I am writing about it now because I hope that other women can benefit from my experience,” she wrote. “Cancer is still a word that strikes fear into people’s hearts, producing a deep sense of powerlessness. But today it is possible to find out through a blood test whether you are highly susceptible to breast and ovarian cancer, and then take action.” After surgery her risk of developing breast cancer in later life fell from 87% to 5%.


The actor’s decision to tell her story was welcomed by medical experts and campaigners worldwide. But did women heed Jolie’s call?


Writing in the British Medical Journal, Sunita Desai and Anupam Jena of Harvard Medical School describe how they sought to answer the question by scrutinising data on US health insurance claims from more than nine million women aged between 18 and 64 .


These revealed that in the 15 working days following Jolie’s article, daily rates of testing for harmful mutations in BRCA1 and BRCA2 genes rose by 64%, compared with the 15 working days before. After six months, average monthly testing rates were still 37% higher than in the four months before the article’s publication.


But the study also reveals that while genetic testing rates increased, there was no change in average, overall mastectomy rates in the six months following the article’s publication – and showed a slight drop in mastectomy rates among those who had BRCA tests.


“The fact that mastectomy rates dropped after Angelina Jolie’s editorial suggests that that denominator of women who started getting the BRCA test became less appropriate for the BRCA test because they had a lower pre-test probability of having the mutation in the first place,” said Desai.


However, Douglas Easton, professor of genetic epidemiology at the University of Cambridge, noted that the study did not offer insights into the BRCA test results – meaning it was not possible to say whether women taking the test received negative results, or whether they had tested positive, but decided not to undergo surgery.


But Jennifer Litton, associate professor in the department of breast medical oncology at the University of Texas, said the results reflected what had been seen in clinics.


“The ‘Jolie effect’ was real, and we did have many more breast cancer patients ask about the test,” she said. “As only a small proportion of breast cancer patients harbour an abnormal gene, those that met national guidelines for testing had already had testing, so it did not change that group with the highest risk of a positive test.”


The research is not the first to explore the impact of Angelina Jolie’s declarations, although previous UK-based studies found that both testing among women at risk, and subsequent preventative surgery, increased.


A co-author of the UK-based research, Tony Howell, professor of medical oncology and director of scientific research at Prevent Breast Cancer, says the new US study looked at too short a period after publication of Jolie’s article to truly reflect its impact. “It takes weeks or months to get through the testing process in proper centres,” he said. “Same applies to risk-reducing breast surgery. This takes one to three years to filter through to surgery if all the checks and counselling are performed properly.”


Overall, says Howell, the 2013 article was valuable in raising awareness. “Jolie did a terrific job,” he said.



"Angelina Jolie effect" boosted genetic testing rates, study suggests

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