FDA approves at-home test kits for inherited cancer: how useful are they?
https://www.facingourrisk.org/XRAY/fda-approves-dtc-testing
Full article: www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm599560.htm
Genetic testing for health conditions (such as risk for cancer) typically requires a prescription from a doctor. Until recently, direct-to-consumer (DTC) genetic testing has focused on tests to learn your ancestry and find of unknown branches of family trees. A laboratory called 23andMe that provides direct-to-consumer genetic testing has been given FDA approval to report results for 3 mutations found in the BRCA1 and BRCA2 genes. The FDA statement provides details about this approval and warns people about the limitations of the 23andMe test. (03/19/18)
Expert Guidelines
At the present time, this approval does not lead to any changes in recommendations for genetic counseling and testing. The National Comprehensive Cancer Network is a consortium of experts in cancer and genetics. They publish consensus guidelines for genetic counseling and testing for cancer risk.
- According to NCCN, cancer risk assessment and genetic counseling is highly recommended before genetic testing is offered (pre-test counseling) and after results are disclosed (post-test counseling). A genetic counselor, medical geneticist, oncologist, surgeon, oncology nurse, or other health professional with expertise and experience in cancer genetics should be involved early in the counseling of patients.
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NCCN cautions about genetic testing through companies that provide ancestry testing (such as 23andMe). Commercial entities providing ancestry (and sometimes health) information typically do so through a type of testing known as “SNP-based testing”. This testing has not been validated for clinical use. Research suggests that the error rate for these tests may be substantial.
In their approval, the FDA make the following notes about test results through 23andMe:
- Consumers and health care professionals should not use the test results to determine any treatments, including anti-hormone therapies and prophylactic removal of the breasts or ovaries. Such decisions require confirmatory testing and genetic counseling.
- The test also does not provide information on a person’s overall risk of developing any type of cancer. The use of the test carries significant risks if individuals use the test results without consulting a physician or genetic counselor.
- The test only detects three out of more than 1,000 known BRCA mutations (the three most common in people of Ashkenazi Jewish ancestry). This means a negative result does not rule out the possibility that an individual carries other BRCA mutations that increase cancer risk. All individuals, whether they are of Ashkenazi Jewish descent or not, may have other mutations in BRCA1 or BRCA2 genes, or other cancer-related gene mutations that are not detected by this test. For this reason, a negative test result could still mean that a person has an increased risk of cancer due to gene mutations.
Questions To Ask Your Health Care Provider
- Given my personal and family history, will this test be informative?
- Are there other options for genetic testing? How do they compare to this test?
- If I test negative, should I consider further genetic testing?
- If I test positive, what is my cancer risk? What preventative measures could I consider? Should I consider different treatment options?
- Should I share my 23andMe results with my relatives? Which ones?
- Can you refer me to a genetic counselor?
About FORCE
FORCE is a national nonprofit organization, established in 1999. Our mission is to improve the lives of individuals and families affected by adult hereditary cancers.