Cancer Genetics Risk Assessment and Counseling (PDQ®): Genetics - Health Professional Information [NCI] - The Option of Genetic Testing
Table 1. Clinical Utility of Genetic/Genomic Testsa continued...
Trends in DTC marketing of genetic tests
In 2002, a search of Internet-based studies found 14 genetic testing companies advertising adult health-related susceptibility testing, with only three companies actually offering testing directly to the public.[15,16] A 2005 and 2006 study identified 24 Internet-based companies providing DTC testing. The companies surveyed offered diverse types of testing, including diagnostic tests for single high-penetrance diseases, such as Huntington disease; risk assessment tests for polygenic diseases, such as breast cancer and Alzheimer disease; and testing for many low penetrance genes that may have ramifications for health or well being, such as nutrigenomic or nutrigenetic tests or cardiovascular profiles. About one-quarter (24%) offered diagnostic and risk assessment tests; 21% offered all genetic tests; 21% offered enhancement tests only; 17% offered risk assessment and enhancement tests; 13% offered diagnostic tests only; and one company (4%) offered risk assessment tests only. The investigators for this study defined enhancement test as a test for one or more low-penetrance genes for the purpose of providing information on general aspects of health, nutrition, and/or treatment regimens, such as nutrigenetic or pharmacogenetic tests and cardiovascular health profiles. This study also examined the content of the Internet information and found that companies offering diagnostic and risk assessment tests were much more likely to indicate that a physician associated with the company would be involved in interpreting the tests than companies offering enhancement testing. Of these companies, eight did not require a physician to be involved in ordering tests or interpreting the results. More than 75% of the 24 companies stated that they recommended or provided phone-based genetic counseling services. When genetic counseling was offered by the company, there was no information provided about the qualifications of the counselors and the scope of the information and counseling provided.
DTC genetic testing in children
One study identified 48 DTC companies and was able to contact 37 of them between December 2009 and April 2010 regarding participation in a survey about their company policies for testing children. Thirteen of the 37 companies participated in the survey, despite guarantees of confidentiality. Ten of 13 (77%) comnpanies reported that they allowed genetic testing of minors; of these ten, nine reported receiving requests to test minors from parents or legal guardians. One company reported receiving a direct request from a minor to be tested. The investigators did not collect data on the types of tests the DTC companies provide; however, the implication is that most of the tests offered evaluate genetic susceptibility to adult-onset disorders.
Concerns about marketing of DTC genetic tests
Several professional organizations have released position statements or recommendations cautioning against DTC advertising and provision of genetic tests. The main concerns that are expressed within these statements include the following:
- Patients may lack knowledge in key areas, such as the purpose and appropriateness of testing, accuracy, follow-up implications, clinical significance of results for themselves and other family members, or the reliability of the laboratory.
- The lack of required health care provider involvement and the lack of stated qualifications of the health care providers utilized by the companies themselves directs the onus on the patients to interpret complex findings or to take the initiative to seek other opinions.
- The lack of adequate regulatory oversight of laboratory tests documenting the analytic and clinical validity and clinical utility prior to test availability.