Genetic Testing - To Test or Not to Test?
by Diana Price 2/2019
Anne Parker is, quite literally, a poster child for genetic testing. Since 1998 Anne’s family history of breast and ovarian cancer has been on display at the Tech Museum of Innovation in San Jose, California, as part of a larger exhibit on genetics. And yet, in Anne’s own close-knit Canadian family, the issue of genetic testing is fraught. For Anne’s son and his cousins, the idea of being tested for the BRCA1 mutation raises specters of fear, grief, and anxiety related to Anne’s own battles with breast and ovarian cancer and their loss of other family members to the disease. Anne’s friend, Kimberly Whitnell, describes the way this particular family is managing the issue of genetic testing.
When Anne Parker, after surviving breast cancer at age 29 and ovarian cancer at age 38, learned in 1998 that she carried the BRCA1 mutation, she began a dialogue about genetic testing with the five most important people in her life: her son (her only child), her two nephews (sons of her late sister, who died in her thirties of ovarian cancer), and her two nieces (the daughters of her brother, who learned in 1999 that he carries the predisposition to cancer). But the dialogue has been difficult. For the generation of young adults in this family touched by hereditary cancer, the suggestion of being tested for the BRCA1 mutation arouses a cascade of difficult emotions and decisions.
Over the years, as research has repeatedly shown the effectiveness of prevention and screening interventions to improve the risk of BRCA1 mutation carriers, Anne has reminded each of them of the importance of being tested. And Anne’s requests have become more fervent as the years have passed. Yet to date none of these young men and women have had the simple blood test that, in Anne’s mind, would either free them of their worries or allow them to manage a diagnosis. “Once it was confirmed that I do carry the mutation,” Anne says, “I thought they would be standing in line to be tested.”
But for this younger generation, who range in age from late twenties to mid-forties, it seems the issue is not as clear. “I have come to realize that you can’t underestimate the personal reasons for not being tested,” Anne says. “Today genetic testing has raised numerous issues related to the risks and the impact of being tested—there are privacy concerns, insurance issues, and employment to think of.” And though she understands the concerns, Anne remains disturbed by her family’s reluctance. “I am distressed, worried, and just a bit angry,” she says about the resistance her family has exhibited toward genetic testing. “The anguish I had to endure both physically and mentally before making the decision to be tested wasn’t just about me; I was also trying to protect other family members from going through the same suffering.”
Despite her own feelings of distress, Anne says, she has continued to encourage her family to at least be aware of their risk—to talk to their doctors, study the research, and, most important, learn about their bodies. But in talking with her family, she has come to learn that in some cases it’s information, as her youngest niece recognizes, that can be both empowering and terrifying: “Knowledge is power,” she said to Anne at one point, “but my fear of the truth makes me feel that ignorance is bliss.”
The responses from her son, her elder niece, and her two nephews have confused the issue further because they all acknowledge the benefit of testing but have been reluctant to actually go through with it. Anne’s son has said that “not to seek knowledge is lazy, if not ignorant, saying nothing of a lifetime of self-doubt.”
Her older niece, a healthcare worker, agreed that “the benefits of knowing outweigh the potential stress of hearing something you didn’t want to hear or deal with.” And her youngest nephew, now a father himself, has said that he believes that testing would be a benefit.
Despite their seeming universal acknowledgment of the positive impact of testing, only Anne’s eldest nephew—who was 17 when his mother died of ovarian cancer—has just recently agreed to be tested. He will undergo the test this year as part of his son’s school project.
Anne knows that the decision to be tested is not an easy one. There are countless situations that weigh heavily on a potential BRCA1 mutation carrier. She faced similar questions herself when she was tested: How does one protect his or her family if they are denied life and health insurance? How does a young executive dedicate his or her time to climbing the corporate ladder, knowing that a ticking time bomb could detonate any day? How does a parent tell a child that he or she has passed on a legacy that is unfathomable?
And then there are the difficult personal choices that might arise following testing. For Anne’s nieces, testing positive for the mutation could force them to make decisions they’re not prepared for at this point. They can ignore the results and trust that they will be spared the anguish that has haunted the women before them, they can select intensive screening, or they can opt for prophylactic surgery and have their breasts and/or ovaries surgically removed. But at the ages of 28 and 30, such decisions make for a cruel reality.
For the young men in the family, for whom the implications of a positive test are much less threatening, the decision to be tested appears no easier. At one time or another, each of these young adults has buried a beloved mother or an aunt, and they all have shared Anne’s pain during her three separate cancers. Perhaps it is not so surprising that the potentially lifesaving step of booking an appointment with a genetic counselor is such a complicated choice.
The struggles that Anne’s family has experienced make clear the broad range of issues and the intense emotions related to genetic testing. Though each family is unique and will handle the situation in their own way, the challenges that exist surrounding the incredible potential benefit of the test and the psychological impact of the related decisions are universal and cannot be underestimated.
It’s in the Genes: Genetic Testing Tutorial
Advances in genetic testing are offering women more information than ever before about their genetic makeup and are providing opportunities for empowered decision making related to a wide range of health issues. In this recurring column, experts provide vital information about how genetic testing suits one’s individual needs, potential risks and benefits, and the role of genetic testing in advancing treatment approaches that target cancer and other diseases.
Genetic Testing Tutorial
*If you are considering genetic testing, it’s important to understand the purpose and scope of available genetic tests.*In a survey conducted by Anna Middleton, PhD, MSc, RGC, of the Sanger Institute, 7,000 people were asked whether they would want to know what’s in their DNA. Interestingly, 98 percent of those surveyed said yes, even if the findings revealed a gene linked to a serious health condition.1The results revealed a general sense of excitement about the idea of preserving one’s health through the use of genetic information. Also indicative of this trend: when actress Angelina Jolie announced her decision to have prophylactic surgery to reduce her inherited risks of breast and ovarian cancer, genetic testing rates increased significantly.2As the science of genetics advances, the possibility of disease prevention is intriguing. But navigating the maze of genetic-testing options can be tricky. If you are considering learning more about what’s in your DNA, it is important to understand some of the nuances. We have bucketed DNA tests into five distinct categories to help simplify the information available to you.
Recreational DNA Tests
A recreational DNA test is one that gives you some fun tidbits about you and your family, such as ancestry, bitter taste perception, or the propensity for freckles. Recreational DNA tests do not require the involvement of a healthcare professional and are not used to make medical decisions. Some recreational DNA tests market their kits as “wellness” or “health” tests, but the fact is that the genetic components of your overall health are complex and cannot be attributed to any one particular DNA finding. If you want to learn about some interesting physical or ancestral traits, a recreational DNA test can be a cool family activity. These tests should not be confused with medical advice.
Predictive DNA tests
A predictive DNA test is one that is ordered and interpreted by a physician, genetic counselor, or qualified health professional. There are thousands of predictive DNA tests, and they are used to determine whether you may have inherited (or can pass to children) a particular disease, such as colon cancer, Huntington’s disease, or cystic fibrosis. Some predictive DNA tests are actionable, while others are not. An actionable result means that you can use the information to reduce your risks or plan ahead, as Angelina Jolie did with her DNA test for breast and ovarian cancer. Testing for Huntington’s, a degenerative neurological disease with no available treatment, is not actionable. Despite the fact that there is no medical action to take, some people feel that simply knowing their risk allows for preparation, estate planning, and relief from the burden of the unknown. Predictive DNA tests are used for medical decision-making during adulthood or pregnancy, and the choice to pursue the information is very personal.
Diagnostic DNA Tests
A diagnostic DNA test is also ordered by a physician, and it is used to help figure out the underlying cause of symptoms in a patient experiencing health issues. For example, a child who has delayed walking or difficulty balancing may undergo neurological DNA tests to look for certain types of inherited muscular dystrophy.An exciting new area within the field of diagnostic testing is whole-exome sequencing. Rather than focus on targeted genes, whole-exome sequencing looks at all of a patient’s DNA to determine the potential cause of a disease.
Therapeutic DNA Testing
Certain therapeutic DNA tests can guide decisions regarding which therapies or medications are best for a particular diagnosis. One example involves the biomarker called HER2 (human epidermal growth factor receptor 2), which provides therapeutic insight in about 20 percent of breast cancer cases. The HER2 gene, when mutated (called HER2-positive), codes for a protein that advances cancer cell growth. A HER2-positive breast cancer tends to be less likely to respond to hormonal therapy; however, hormonal treatments that specifically target HER2 are very successful. These treatments are in fact so effective that the prognosis for HER2-positive breast cancer is quite good.
Research Genetic Testing
Some genetic tests are available as part of research, often as part of clinical drug trials. The scope of results may be limited, however, because the research is often designed to accelerate drug development rather than provide health information. The results from such testing are usually not available to patients or to the referral source, and enrolled family members may not get results from this type of testing. If you are considering research genetic testing, talk with your doctor, genetic counselor, or other healthcare professional about the benefits and limitations.
As you can see, most of the time the information you will receive from DNA testing is really useful. But there are times when results are difficult to interpret or may bring up unknown variables (nonpaternity as a classic example). Understanding the benefits and limitations of testing options is important so that whatever path you choose, you are comfortable with the decision.
- Middleton A, Morley KI, Bragin E, et al. Attitudes of nearly 7,000 health professionals, genomic researchers and publics toward the return of incidental results from sequencing research. European Journal of Human Genetics. 2016;24(1):21-29. doi: 10.1038/ejhg.2015.58.
- Evans DG, Barwell J, Eccles DM, et al. The Angelina Jolie effect: How high celebrity profile can have a major impact on provision of cancer related services. Breast Cancer Research. 2014;16(5):442. doi: 10.1186/s13058- 014-0442-6.