23andMe gets FDA green light for cancer risk test

Genetic testing powerhouse 23andMe announced today that it’s officially received the FDA go-ahead to launch a direct-to-consumer testing kit for genes linked to various forms of cancer. The forthcoming kit, which will be made available without a prescription, tests for BRCA1 and BRCA2, which are linked to higher risk of ovarian, break and prostate cancer.

“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,” the company’s CEO Anne Wojcicki said in a release tied to the announcement. “We believe it’s important for consumers to have direct and affordable access to this potentially life-saving information. We will continue pioneering a path for greater access to health information, and promoting a more consumer-driven, preventative approach to health care.”

Of course, the test shouldn’t be taken as the be all, end all of cancer risk — nor is it meant as a replacement for a proper screening. As geneticist Eric Topol notes on The Verge, the three variants tested here only make up a small percentage of hundreds of known mutations. The test has the potential to provide a false sense of safety among consumers.

Topol’s warning reflects an FDA letter sent to the service back in 2013, urging 23andMe to discontinue marketing its Saliva Collection Kit and Personal Genome Service.

“Some of the uses for which PGS is intended are particularly concerning,” the FDA writes, “such as assessments for BRCA-related genetic risk and drug responses (e.g., warfarin sensitivity, clopidogrel response, and 5-fluorouracil toxicity) because of the potential health consequences that could result from false positive or false negative assessments for high-risk indications such as these.”

The three variants of the gene are found most often in people of Ashkenazi Jewish descent, with one in 40 people of that background carrying one. In women, the presence of one of the variants increases breast cancer risk by up to 85 percent before age 70. As the service notes, around half of BRCA carriers who offered medical history in a study don’t report cancer history among immediate relatives.

In that respect, the service could potentially raise a red flag and lead customers to get an additional screen. But, of course, the results of the test should in no way be taken as a replacement for a visit to the doctor.