The perseverance and scientific innovation of Dr. Mary Claire King, the geneticist whose efforts to identify the BRCA genes were initially scoffed at by her peers, cannot be underestimated or underappreciated. Her drive and desire to find better tools to address the breast cancer epidemic are shared by activists, researchers, geneticist, and patients alike. But her new recommendation, published in the Journal of the American Medical Association -- that all women in the United States over age 30 be screened for BRCA mutations linked to breast and ovarian cancer -- fails as a matter of public health to recognize the significant limitations, and harms, of mass genetic testing in the current health care environment.
In proposing that genetic testing for the BRCA1 and BRCA2 genes become routine for all women over age 30, Dr. King focuses only on what she sees as the potential benefit, of identifying women with genetic mutations that increase their risk of cancer, and minimizes the harms that result from exposing all 105,000,000 women age 30 and over in the U.S. to genetic testing without access to genetic counselors who can explain tests or results.
Genetic testing is complex, and brings with it a wide range of medical, ethical and scientific issues -- despite years of medical training, even many physicians don't fully understand all the complexity involved. And though I share Dr. King's concern that "only 19 percent of US primary care physicians accurately assessed family history for BRCA1/BRCA2 testing," I disagree that we can solve that problem by removing doctors and genetic counselors from the testing process.
Failure to discuss and acknowledge the limitations, harms and options of any medical test or procedure deprives patients of their right to make informed decisions about their bodies and their health care. Understanding genetic testing is particularly complex and requires trained genetic counselors, both before and after testing. Genes are not simply binary switches and knowledge of a mutation brings a complex set of choices that are challenging to navigate for patients. The very nature of inherited genes means that these issues extend to other generations -- meaning this complex set of ethical, legal, medical and life-course questions extend from individuals to their blood relatives, who may be effectively deprived of privacy and the right to self-determination. Unfortunately, there aren't even enough trained genetic counselors to attend to the number of people who are getting BRCA testing now, let alone with mass population-wide screening.
Furthermore, the current BRCA tests leave a significant number of people (between 3 and 10 percent of those who undergo testing) with the knowledge that they have a mutation on the BRCA gene that may or may not be harmful, what is called a "variant of unknown significance." But we all have any number of genetic mutations, many of which are benign and do not increase our risk of cancer. As Dr. King herself says: "The challenge is not identification, but interpretation, of making sense of [the BRCA mutations that are] identified."
Dr. King's solution to these mysterious mutations? Only tell patients about those mutations which we know to be linked to cancer and exclude all variants of unknown significance, which knowing about could, in Dr. King's words, "increase confusion and compromise clinical management". Rather than simplifying matters, this proposal underscores the deep problems of population-wide BRCA testing without genetic counseling; women whose test reports finding no mutation "with definitive effect on cancer risk" may be misled about their cancer risk when information about variants of unknown significance is omitted. To suggest that we simply not inform women about mutations we don't fully understand creates a whole different ethical dilemma and is a violation of the right to full information about the medical procedures to which we consent.
It is wrong to ask people to undergo genetic testing without receiving professional counseling to explain the limitations of the test and informing them of the test's results -- even the ambiguous results. Limiting population-wide testing to only variants we currently understand is ultimately an inadequate way to address the gaps in Dr. King's proposal.
It is sobering that Dr. King's drastic proposal is based on one small study in Israel of Ashkenazi Jewish men, an ethnic group known to have a much higher prevalence of BRCA mutations. While BRCA mutations are rare in the general population (only about 1 in 600 to 800 women), they are common among Ashkenazi Jews (about 1 in 40 women). And, despite common misperceptions about inherited breast cancer risk, only an estimated 5 to 10 percent of breast cancers are even linked to BRCA mutations.
Initiating mass genetic testing for a rare genetic mutation that is linked to only a fraction of all breast cancers is not going to stem the breast cancer epidemic. And we must question a public health strategy that will cost hundreds of millions of dollars -- even after last year's Supreme Court ruling opened up BRCA testing, commercial tests still start at $1,000 a person and up -- to find people who are at increased risk of cancer, but may never get cancer. Just an initial screening of the current population of women over 30 would cost $105 billion.
As the head of an organization dedicated to public health interventions to address and end the breast cancer epidemic, if Dr. King's proposal would make a dent in the breast cancer epidemic, even at a cost of $105 billion, I'd be among the first to advocate for it. But there are so many other parts of the breast cancer-care continuum that could benefit from even a fraction of $105 billion. With that kind of money, we could give all women who need it access to affordable, high-quality, culturally-competent care; we could fund research to further our understanding of how to treat metastasis, and prevent it in the first place; we could address the appalling, vast racial disparities in breast cancer death rates; and we could even fund research to help understand why some women with BRCA mutations never get cancer, and thus learn more about how to prevent breast cancer.
I am all for access to genetic testing when medically indicated -- in fact, Breast Cancer Action was the only breast cancer organization to join the lawsuit challenging Myriad Genetics for their patent stranglehold on the BRCA mutations, which we won at the U.S. Supreme Court last summer. And I agree with Dr. King that women need better risk assessment tools for breast cancer, one piece of which includes genetic and inherited risk.
But the answer to the breast cancer epidemic does not rest with mass genetic testing -- and the more we look for answers in individual women's bodies, the less we focus on the societal, systemic factors driving the epidemic in the first place.