Proponents of DTC genomic profiling suggest that the clinical usefulness of SNP-based testing will improve based on emerging data that analyze the interaction between genetic polymorphisms and environmental factors in predicting disease risk. For example, preliminary studies evaluating SNPs associated with colorectal cancer have found that relative risks are increased when combined with environmental factors, such as high intake of processed meats.16,17 Despite these early findings, it remains to be seen whether the complexity of gene-environment and gene-gene interactions can be elucidated to the extent that will be required to yield highly predictive DTC tests.
Is DTC advertising accurate, fair, and helpful?
Point: DTC advertising overemphasizes the benefits of testing and does not adequately describe the limitations and risks.
Unlike pharmaceutical advertising, which is tightly regulated and requires companies to discuss associated risks, oversight of genetic testing advertisements is limited.18 This can lead to skewing of information that overemphasizes the benefits of genetic testing and does not adequately define the risks and limitations.19,20 One recent study demonstrated that when individuals are provided with accurate information regarding the actual risks and limitations of online DTC genetic testing, they have reduced intentions to obtain such tests and less positive views of Internet-based testing. 19 Furthermore, an investigation of DTC advertising revealed “egregious examples” of deceptive marketing, such as claims that consumers’ DNA could be used to create personalized supplements to cure disease or that results of such DNA tests could be used to predict the athletic potential of their children.14
Many DTC companies have a clause indicating that their testing is intended for research, educational, or entertainment purposes only, and not for diagnostic or medical use. However, this clause is embedded deep into the Web site and surrounded by text like “disease risk prediction,” “predicted response to drugs,” and a long list of serious medical conditions that appear to be anything but entertainment- based. Together with mundane traits, such as bitter taste perception, freckling, earwax type, and hair thickness, consumers are tested for susceptibility to amyotrophic lateral sclerosis, bipolar disease, heroin addiction, and cancer predisposition. This strange combination of offerings makes it difficult to determine whether this testing is truly entertainmentbased or a serious predictive testing panel requiring careful interpretation by a medical professional.
Complicating these issues even further, several DTC testing companies do not fully explain which SNPs or gene mutations are evaluated in their specific disease risk profiles. Therefore, the average woman may think she has had comprehensive sequencing for BRCA1 and BRCA2 because her “breast cancer risk” has been assessed, when in fact she has been tested for a panel of low-risk SNPs and only the three common Jewish BRCA mutations. For a non-Jewish patient, these results would be virtually meaningless in terms of assessing hereditary risk.
Even well-versed genetics professionals may not be able to decipher the implications of tests offered by some companies. Recently, a cancer genetics professional reported that she reviewed a multigene-disease panel offered by one DTC genetic testing company that reportedly included testing for MYH-associated polyposis. When she discussed this test with the company, she discovered that it provided analysis for only one of the two common MYH mutations in Caucasians (unpublished, personal communication). These important omissions could lead both patients and clinicians to think that comprehensive testing has been performed when, in fact, it has not.
Counterpoint: DTC advertising has increased physician and patient awareness of genetic testing and technology.
As consumers become more sophisticated in their medical knowledge base, many are turning to the Internet for healthcare information before, or instead of, addressing their concerns with a medical professional. Although medical information on the Internet is of varied accuracy, obtaining medical information online is a trend that is here to stay, and genetic testing is no exception. The DTC genetic testing companies have exploited this thirst for medical information and have developed educational information on basic “Genetics 101” concepts for the lay public. For example, 23andMe, a DTC genetic testing company, describes genomic testing through an animated video clip using cartoon characters on its Web site. This new educational delivery system not only helps the genetic testing company sell their product but also helps the consumer learn more about genomic technology. In response to DTC genetic testing, many medical groups have launched educational campaigns to help bring clinicians up-to-date on the genetic testing their patients may be pursuing and bringing to their office.
Many professional medical organizations have addressed this gap in knowledge and have continually offered additional training regarding regarding the implications of genomic and genetic technologies in their subspeciality. Oncology has been at the forefront of this movement, offering training to oncologists through the American Society of Clinical Oncology to expand the knowledge base on genetic and genomic testing.