This article was originally published in Scientific American
The advent of technological innovations makes it possible for us to know more about ourselves than ever. We can quickly and easily use consumer-grade devices and apps that track steps, monitor heart rates and check blood glucose levels. But when it comes to disease risk, quick and easy can also mean inadequate and potentially dangerous. Genetic testing is part of precision medicine, an approach using genetic and molecular profiling to potentially optimize health care for individual patients. But not all tests are created equal. Unlike certified genetic health risk (GHR) tests, consumer-grade assessments are not true medical tests. These products such as 23andMe, AncestryDNA or Living DNA are extremely popular among consumers, yet they are no replacement for licensed medical advice or screening. Even with careful wording on the packaging, it’s easy to miss important limitations on a test’s scope, or to misunderstand critical nuances in the results. For some users, the desire for insights leads them to believe some information is better than none. Adding to the confusion is the fact that the IRS has determined that consumers can use flexible or health spending accounts to cover the costs of 23andMe’s GHR assessments. The Food and Drug Administration (FDA) also approved 23andMe’s ability to provide information about genetic variants that may be related to a patient’s ability to metabolize certain medications. This may further mislead people into thinking these tests are clinically sound. Again, they are not. And that is the danger: consumer-grade products are easily misconstrued as appropriate medical tests and create false reassurances in patients who could be at legitimate risk. As an oncologist studying the genetics of cancer, I am particularly concerned about consumer GHR testing for heritable cancer risk. As an example, the 23andMe consumer test of BRCA1 and BRCA2 screens for only three of the more than 1,000 BRCA clinically important variants. These three mutations affect only two in 100 women from Ashkenazi Jewish backgrounds, and one in 1,000 women in the general population. Thus, the results are inadequate for most people at high risk of cancers associated with inherited mutations in BRCA1 or BRCA2 genes, including families whose members have experienced ovarian cancer, male breast cancer, multiple early breast cancers, pancreatic cancer or prostate cancer. Put simply, this recreational test has zero value for the majority of people who may need it for true medical purposes. And here is why that’s important: I recommended that one of my patients with the BRCA2 inherited cancer risk mutation encourage his first-degree relatives to take a certified GHR test since there is a 50 percent chance they could also carry the mutation. If they do, it doesn’t mean they will get cancer, but the knowledge may provide them important options for reducing risk of cancer or preventing cancer. The patient’s brother had taken the 23andMe test, which showed no mutation—because the patient’s mutation would never have been picked up by the consumer test. The brother was falsely reassured that he didn’t carry the mutation, when in fact he had not been appropriately tested. On the contrary, he should be getting a medically appropriate GHR test that accurately assessed the BRCA2 gene, especially one that could detect the mutation his brother carried, to evaluate his risk. The FDA is not unaware of the potential confusion in the marketplace, and addressed it directly in its approval of 23andMe’s BRCA tests: “The test should not be used as a substitute for seeing your doctor for cancer screenings or counseling on genetic and lifestyle factors that can increase or decrease cancer risk,” the agency’s news release noted. “The use of the test carries significant risks if individuals use the test results without consulting a physician or genetic counselor.” But most consumers don’t read carefully or truly consider the fine print. The hazards associated with consumer tests extend well beyond cancer risk. These products also offer tests for diabetes, celiac disease, Parkinson’s disease and others, meaning many people could be similarly lulled into a false sense of security about their health. If you were considering surgery, would you be satisfied by the opinion of someone who played a lot of the board game Operation, or would you instead seek a professional, highly trained surgeon with years of experience? That’s one way of thinking about the difference between recreational tests and medical tests. “Risks associated with use of the 23andMe tests include false positive findings, which can occur when a person receives a result indicating incorrectly that he or she has a certain genetic variant, and false negative findings that can occur when a user receives a result indicating incorrectly that he or she does not have a certain genetic variant,” the FDA approval noted. “Results obtained from the tests should not be used for diagnosis or to inform treatment decisions. Users should consult a health care professional with questions or concerns about results.” In other words, regardless of the results from direct-to-consumer genetic tests, a person should specifically discuss if they have a family history of hereditary conditions or want to understand their risk of carrying a specific genetic or molecular mutation with their doctor or a genetic counselor. In fact, discussing genetic and molecular testing is a terrific topic for your next visit to your health care provider. Medical-grade genetic testing has the potential for far-reaching advancement and opportunities for faster diagnosis, and more effective prevention and treatments. Lifelong well-being is too important to rely on a recreational genetic test when rigorously tested medically appropriate options for your particular health are available.
The views expressed are those of the author(s) and are not necessarily those of Scientific American.
Heather Cheng, M.D., Ph.D., is a board-certified medical oncologist at Seattle Cancer Care Alliance and Brotman Baty Institute member, a University of Washington Associate Professor of Oncology, and Associate Member of Fred Hutch’s Clinical Research Division.
Link to originally published article.