Today (March 6), the US Food and Drug Administration approved 23 andMe’s at-home genetic test as a diagnostic tool for increased risk of breast, ovarian, and prostate cancer.
This test analyzes a sample of saliva and screens for three mutations of the BRCA1 and BRCA2 genes. In women, these mutations can raise the likelihood of developing breast cancer from 12% (the average baseline) to 45% to 85%, and of developing ovarian cancer from 1.3% to between 17% and 44%. In men, the mutations also raise the risk of breast cancer, and possibly prostate cancer as well, although the research is less clear for the latter.
The vast majority of people with these genetic mutations have ancestral ties to the Ashkenazi Jewish population formerly living in central Europe and Russia. Roughly one in 40 people with this heritage will carry these genetic variants.
23 andMe’s test involves taking a simple saliva swab at home, and sending it to the company’s labs for analysis. It’s the first at-home BRCA1/BRCA2 screening tool to be approved for use in the US, and could significantly raise the number of people aware of having the cancer-related mutations. Currently, pretty much all BRCA1 and BRCA2 screenings are called for by a doctor, for patients already identified as either having cancer, or as having a high risk of cancer.
This test is far from definitive: There are thousands of mutations on the BRCA genes alone that can raise a person’s risk of developing cancer, and 23 andMe’s test can only identify three. (These three are also not the most common BRCA mutations.) The testing done in professional medical labs is more detailed, and can definitively find more of genetic risk factors. However, even prescription-ordered genetic testing is not 100% conclusive that a person will develop cancer or not.
Currently, 23 andMe’s health risk tests comes bundled with ancestry testing, and costs $199. The new BRCA testing will come as part of the package; a spokesperson for the company confirmed that it will be available in the coming weeks.