The agency therefore warned that individuals and their physicians should not use the test results to make decisions about treatments, including prophylactic removal of the breasts or ovaries. That should be based on more extensive testing. Myriad Genetics, which developed the first BRCA1/2 tests, assesses DNA for thousands of variants; it has long warned that other tests, which came on the market after the Supreme Court threw out Myriad’s key BRCA patents, could mislead women.
In addition, most cases of breast cancer are not hereditary, from BRCA or other mutations, but “sporadic,” meaning they arise at random or from smoking, obesity, exposure to toxic chemicals, hormone use, and other environmental factors.
“At a minimum, 23andMe should be clear with people about what their test is and isn’t and present the information in a fair and balanced way that the average person can understand,” said Myriad spokesman Ron Rogers, who added that some customers might be uncomfortable about 23andMe’s selling of genetic information to third parties.
For women with Ashkenazi ancestry, the test “is not too bad as a screen,” said Robert Cook-Deegan of Arizona State University, a longtime scholar in the field of genomics ethics and law. “But for other groups with different founder mutations, and there are many, it won’t help much. There’s a big need for users to understand that nuance, which is not widely understood.”
The FDA’s decision was based on data from 23andMe showing that its test can accurately identify the three genetic variants in saliva samples. The privately held company also submitted studies showing that consumers understood the report it will send to customers on what the results might mean, how to interpret them, and where to find additional information.
“Being the first and only direct-to-consumer genetics company to receive FDA authorization to test for cancer risk without a prescription is a major milestone for 23andMe and for the consumer,” Anne Wojcicki, 23andMe CEO and co-founder, said in a statement. “We believe it’s important for consumers to have direct and affordable access to this potentially life-saving information. … This authorization is incredibly valuable for those who might not be aware of their Ashkenazi Jewish descent.”
She, too, emphasized that “our test does not account for all genetic variants that can cause a higher risk of cancer, and people should continue with their recommended cancer screenings.” Myriad, for instance, has identified some 20,000 BRCA1/2 variants.
The decision follows one last year in which the FDA gave 23andMe the go-ahead to sell DNA tests assessing customers’ risk of 10 diseases, including Parkinson’s and late-onset Alzheimer’s. Those were the first FDA-approved direct-to-consumer tests for genetic risk of any disease or condition, which the agency said could help people make lifestyle decisions. At the time, the FDA also warned that genetic risk for complex diseases is not a sure thing: People whose 23andMe test does not find genetic variants that increase the risk of a disease can still develop it, and people whose DNA test shows no disease-causing variants might not.
The BRCA test will be part of 23andme’s $199 Health + Ancestry test. Existing customers can opt to receive BRCA information for no additional cost, and as with the other disease-risk tests they as well as new customers must specifically choose to receive the information.
“My libertarian streak says this, properly understood, is a good thing that increases access,” said Cook-Deegan, “although I do worry about proliferation of commercial purveyors as the sources of information and keeping the data.”