What Can 23andMe Results Tell You About Your Breast Cancer Risk?
Yesterday, the FDA announced that it has authorized 23andMe to report out three specific mutations in the BRCA genes.
If the idea of 23andMe reporting out these results sounds familiar, it’s because 23andMe was reporting out these findings in the past—until they were ordered by the FDA in 2013 to suspend all of their health-risk reports.
23andMe has announced that existing customers who ordered their Health + Ancestry test and were genotyped on the company’s recent platforms will have access to these results within the next few weeks.
If you’ve ordered 23andMe’s Health + Ancestry test, what will these results tell you about your breast cancer risk?
For most people—the answer is not too much!
The three mutations that will be reported out are common in individuals of Ashkenazi ancestry, carried by about 1/40 males and females. BRCA mutations are common enough in individuals of Ashkenazi ancestry that the American Society of Breast Surgeons recommends hereditary cancer testing for individuals of Ashkenazi ancestry if they have a personal or family history of breast cancer at any age. Testing for these three mutations is sometimes recommended for individuals of Ashkenazi ancestry even in the absence of any BRCA-associated personal or family history of cancer.
These three mutations, however, are only a few of over 1000 possible mutations in the BRCA genes. For individuals who are not of Ashkenazi ancestry, more comprehensive testing of the BRCA genes is recommended.
For individuals with a significant personal or family history of cancer, testing beyond just the BRCA genes is also often recommended—regardless of ancestry. If you do have Ashkenazi ancestry and a significant personal or family history of cancer, one of these three common BRCA mutations is the most likely culprit and could be a reasonable starting point for testing. But if results are negative, testing of other genes should be considered.
Read more about cancer genetics and the BRCA genes here.
Is more comprehensive hereditary cancer testing affordable?
Comprehensive testing of the BRCA genes and other hereditary cancer genes is usually covered by insurance for patients who meet National Comprehensive Cancer Network (NCCN) criteria based on their personal and/or family history of cancer. (A log-in is required to access the complete NCCN guidelines, but registration is free.)
Notably, Medicare will only cover genetic testing for patients who have a personal diagnosis of cancer. Medicare criteria for patients who do have a personal history of cancer, however, recently became even more generous than NCCN criteria. Medicaid also typically covers genetic testing for patients who meet NCCN criteria, although the wait for prior authorization may be longer than with commercial insurances. For uninsured patients who meet certain financial and medical criteria, some commercial labs offer free testing through charity programs. For patients whose commercial insurance will not cover the cost of genetic testing, there are still more comprehensive testing options available for an out-of-pocket cost that’s not necessarily much higher than the cost of 23andMe testing.
Quality and accuracy of testing does vary between labs and is hard to parse–so ideally, consult with a genetic counselor, and at minimum ensure that your healthcare provider is reasonably informed about different hereditary cancer testing options and has reasons to feel confident about the results from their lab of choice.
Should you have genetic testing done?
Every individual has a unique personal and family history. Genetic counseling can help you make sense of genetic testing options and results within the context of your own personal and family health history. Genetic counseling can help you understand how genetic testing results may or may not impact recommendations for your healthcare and what the implications of your test results would be for your family members.
Further Reading & Quality News Coverage:
Begley, Sharon. “FDA approves first direct-to-consumer test for breast cancer risk.” Stat News. March 6, 2018.
Zhang, Sarah. “23andMe Will Now Test for BRCA Breast-Cancer Genes.” The Atlantic. March 6, 2018.
American College of Medical Genetics and Genomics. March 7, 2018. “ACMG Responds to FDA’s Approval for Direct-to-Consumer Testing for Three BRCA Gene Mutations.”