FDA approves, with reservations, the first home DNA test for genetic breast cancer risk
The FDA has just authorized, for the first time, a direct-to-consumer (DTC) genetic test to report on three genetic variants found on BRCA1 and BRCA2 genes. These genetic variants are known to increase a person's risk for developing primarily breast cancer, but also also ovarian or prostate cancers.
The authorization announcement from the FDA is somewhat unexpected after earlier statements from the agency specifically citing consequences from BRCA home testing as one of the primary concerns surrounding DTC gene testing. Back in 2013, the FDA explicitly referenced the dangers of BRCA-related DTC testing being conducted without the guidance of a doctor or genetic counselor as one of the primary reasons for cracking down on 23andme, the company behind this test.
"If the BRCA-related risk assessment for breast or ovarian cancer reports a false positive, it could lead a patient to undergo prophylactic surgery, chemoprevention, intensive screening, or other morbidity-inducing actions, while a false negative could result in a failure to recognize an actual risk that may exist," wrote the FDA in its warning letter to 23andme in late 2013.
Last year, the FDA loosened its grip on the company a little and allowed it to test for genetic variants linked to 10 different diseases and conditions. Interestingly, the FDA still noted back in April 2017, as part of that approval note, that it would not allow any of these unsupervised genetic tests to report on risk factors that could be considered diagnostic tests.
Again, a little under a year ago, the FDA cited BRCA as one of those specifically disallowed tests, describing a "diagnostic test" as something, "often used as the sole basis for major treatment decisions, such as a genetic test for BRCA, for which a positive result may lead to prophylactic (preventative) surgical removal of breasts or ovaries."
So, while it is unclear what policy shift caused the FDA's recent change of heart, the announcement it published is jam-packed with caveats, highlighting the limitations of 23andme's now approved DTC test. The authorization is quite specific about only allowing the company to report to customers on three BRCA mutations. These are three specific variants that are not the most common BRCA mutations out of over one thousand known variants associated with cancers, and they only account for a fraction of all hereditary breast cancers diagnosed in the United States.
The FDA announcement stresses that the results of the tests are limited in scope, do not mean other cancer-causing gene mutations are not present, and should not be used to determine treatments without other testing and genetic counseling.
While more comprehensive BRCA testing can be undertaken by concerned citizens, it still needs to be ordered and delivered through a doctor so the results are discussed and the implications understood. This FDA approval is the first time this information has been approved to be delivered directly from a private company to an individual.