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A controversial television advertisement in the United States encouraging women to undergo genetic testing to determine their risk of breast cancer has triggered an inquiry into claims made by the advertiser, Myriad Genetics.
The women in the advertisement appear to be in their early 20s to late 50s, and each says she has a relative with breast cancer. A couple of the women say they want to get “BRACAnalysis” to learn about their risk of breast cancer and “do something about it.”
Some cancer specialists say that this “direct to consumer” campaign is unnecessarily alarmist. A New York Times article reports that the Connecticut attorney general, Richard Blumenthal, has issued a subpoena for information about the test saying, “There's enough serious and significant doubt about the accuracy of some of their claims that we feel a strong need to investigate” (www.nytimes.com, 11 Sep, “A genetic test that very few need, marketed to the masses”).
Myriad's president, Gregory Critchfield, said in a statement released on 10 September, “The purpose of the BRACAnalysis public awareness campaign is to save lives. The risks of breast and ovarian cancers are very high in individuals carrying mutations in either the BRCA1 or BRCA2 genes.” Testing, said Dr Critchfield, would allow women at high risk of breast cancer to “take steps to reduce their risk for these cancers.”
The US Preventive Health Services Task Force says that the 2% of women who have a BRCA mutation face a 35% to 84% chance of developing breast cancer by age 70 and a 10% to 50% risk of ovarian cancer by the same age—higher risks than the general population.
However, the task force concluded that there was insufficient evidence to determine whether the interventions offered to women with BRCA mutations, such as prophylactic mastectomy and oophorectomy, could reduce mortality. The task force cautioned that the risks of testing include adverse physical outcomes and financial, emotional, legal, and “social consequences such as insurance and employment discrimination.”
Shannon Brownlee, author of Overtreated: Why Too Much Medicine is Making Us Sicker and Poorer, said, “This looks a lot like fear-mongering. First, advertising will lead many women who have no increased risk to want the test. Among those who test positive, what percentage will undergo prophylactic surgery who may never have developed cancer in the first place? I think this genetic test should have been subjected to a clinical trial proving clinical benefit—not just test accuracy—before it was allowed to be marketed.”
Kay Dickersin, director of the Johns Hopkins Center for Clinical Trials, Baltimore, said the campaign was particularly disturbing because not enough information exists about what to do with the results of genetic testing.
Citing a 2007 Cochrane review, Dr Dickersin said that only observational studies of women who underwent prophylactic bilateral mastectomies had been conducted. “Most of the studies,” said Dr Dickersin, “only looked at the number of women developing breast cancer—very few looked at breast cancer mortality, and none examined all cause mortality.”