Is it a good idea to embark on a genetic hunting expedition to see if you鈥檙e at 鈥渉igh risk鈥� of developing a particular disease?
That question was examined last month when the U.S. Preventive Services Task Force, an independent group of scientists making recommendations on medical screening, issued a warning that BRCA testing to find gene mutations associated with breast cancer should not be sought by women at low risk and unlikely to benefit.
The task force was, no doubt, responding to the Angelina Effect, referring to actress Angelina Jolie who underwent genetic testing for mutations related to the BRCA1 or BRCA2 genes, believing that she may be more likely to develop breast cancer. Coming from a family with a deadly history of breast cancer, Jolie was told she was in a 鈥渉igher risk鈥� category than average and that she would benefit from such testing. After hearing she carried the bad genes, she went ahead with a double mastectomy 鈥� a full surgical removal of both breasts 鈥� and wrote about it in the New York Times.
Not only did this drive sales of the genetic tests for breast cancer into the stratosphere, it also drove legions of women to their doctors saying: (脿 la When Harry Met Sally), 鈥淚鈥檒l have what she鈥檚 having.鈥� The British newspaper The Mirror reported that breast-cancer charities saw a 鈥渇our-fold surge in women enquiring about having their breasts removed.鈥�
The U.S. experts, perhaps responding to this craziness, have recommended that women with a family history 鈥渘ot associated with an increased risk for mutations in the BRCA1 or BRCA2 genes鈥� should decidedly not seek routine genetic counselling or testing.
The fact that women are driven to ask about genetic testing reflects our celebrity-obsessed culture, a strong fear of breast cancer and a somewhat earnest grasp of the 鈥渂etter safe than sorry鈥� mantra that consumes many of us. It鈥檚 likely that the vast majority of those new customers lining up for the test would be classified as the 鈥渨orried well鈥� who would be unlikely to carry the rare genetic mutation and hence would receive no benefit from being screened, and for whom prophylactic removal of one鈥檚 breasts would be an extremely unwise option.
This is not the first time public health authorities have taken note of the health-prevention advice coming from celebrities. People in the screening world also talk about the 鈥淜atie Couric effect鈥� when referring to the massive public impact, in Couric鈥檚 case, of having a colonoscopy performed live on the Today show. This brought massive star power to the issue of colon cancer screening and proved, once again, that virtually nothing trumps celebrity endorsements when it comes to making high-octane public-health appeals.
In fact, public-health communicators study the Couric colonoscopy as a classic case in how to get people off the couch and heading to their doctors to do something they would otherwise find yucky. As only about 50 per cent of 91原创s over 50 routinely partake of regular colon-screening programs that might detect and deflect a potentially fatal colon lesion, Couric鈥檚 star endorsement probably contributed to a good thing: a substantial increase in the numbers of people asking for and submitting to colon-cancer screening.
However, the recent advice from the task force on genetic screening and breast cancer is spot on, and the numbers tell all. Somewhere between two and three in 1,000 women will carry the same genetic anomalies as Angelina Jolie. For women of 鈥渧ery high risk鈥� of the BRCA genes, such as Ashkenazi Jewish women, the rate is about two in 100.
The experts say that women who have one or more family members with a known potentially harmful mutation in the BRCA1 or BRCA2 genes should be offered genetic counseling and testing. Everyone else, and that is most women, should avoid getting tested.
It is difficult to say if the sober recommendations of an august panel like the U.S. Preventive Services Task Force can compete against the star power of a superstar celebrity 鈥� who, it might be noted, never advocated for others to get the test, but detailed her own experience and advocated for 鈥渋nformed choices.鈥�
In any event, we shouldn鈥檛 be too dazzled by celebrity magnetism and dive into screening for the remote possibility of discovering that we are at 鈥渉igh risk.鈥�
Alan Cassels is a University of Victoria drug-policy researcher and the author of Seeking Sickness: Medical Screening and the Misguided Hunt for Disease.
