More companies are offering direct-to-consumer genetic tests to meet consumers’ demands. But Noah D. Kauff, MD, director of Clinical Cancer Genetics for the Duke Cancer Institute, says physicians should warn patients about the limitations of these tests.
Direct-to-consumer tests actually provide a disservice because patients may not know how to interpret them, Kauff says. Furthermore, consumers could gain false assurance regarding their disease risk because direct-to-consumer tests may evaluate only a few specific risk factors rather than all relevant ones.
For example, one company’s genetic test only checks the BRCA1 and BRCA2 genes for three specific mutations to evaluate breast and ovarian cancer risk. But the BRCA1 gene has more than 6,000 chemical letters, and the BRCA2 gene has more than 10,000. “A mutation associated with an increased cancer risk can occur almost anywhere in the 16,000 chemical letters,” Kauff says.
Privacy issues can also arise with direct-to-consumer tests, says Kristin Paulyson Nuñez, MS, CGC, a Duke senior genetic counselor. Certified genetic counselors can partner with physicians to ensure that testing is performed in accordance with Health Insurance Portability and Accountability Act regulations and that patients appropriately consent to testing.
Paulyson Nuñez advises physicians to consider the following when talking with patients about genetic testing:
- Have they previously undergone any genetic testing?
- What is their motivation for undergoing genetic testing?
- What is the best method to determine their disease risk?
Rather than taking a one-size-fits-all approach like direct-to-consumer genetic testing, Kauff says Duke offers a different approach. “We first conduct a detailed review of an individual’s personal and family history,” he says. “Then, a genetic counselor, in concert with the patient, will determine which genetic tests are appropriate. This should be done in a thoughtful and collaborative manner, as testing for syndromes that individuals are not at risk for can lead to false positive results and unnecessary interventions.”
Duke researchers are currently studying the best methods for performing appropriate genetic risk assessments for patients with cancer, which considers their molecular genetic test results in concert with their personal history, family history, and specific pathology. “We’re looking to streamline the approach to better characterize if someone with cancer has an inherited predisposition that should impact their oncology care plan,” Kauff says. “We’re also looking at models of streamlined video-assisted genetic education to see if we can simplify the approach to providing genetic risk assessment, so we can better integrate this evaluation into the routine care of all oncology patients.”