April 18, 2018
In spring of 2018, the
Food and Drug Administration (FDA) granted approval for consumer genetics
company 23andMe to include information about breast and ovarian cancer risk
caused by three BRCA1/BRCA2 mutations
more prevalent among Ashkenazi Jews than other populations in the report it
provides to users of its ancestry and health service. The FDA made their
decision after a review process that determined that 23andMe’s test and results
met appropriate benchmarks for accuracy. However, as the FDA’s press release
noted, these three mutations constitute less than 1% of known BRCA1/BRCA2 mutations, and the receipt
of these test results without guidance from a physician or genetic counselor
may place individuals at risk for other harms.
The Norton &
Elaine Sarnoff Center for Jewish Genetics cautions regarding the use of
direct-to-consumer (DTC) testing such as the 23andMe test to determine one’s
personal risk for hereditary cancer. Those who consider using such tests, or
who receive such test results, should understand these key points:
- The results given by
these tests are extremely limited and potentially misleading. The three
mutations identified in 23andMe’s test represent only a small fraction of more
than 1,000 known cancer-related mutations in the BRCA1/BRCA2 genes. Additionally, this test does not provide any
information about mutations in other genes that can dramatically increase a
person’s cancer risk. While the three BRCA mutations included in the 23andMe
test are the more prevalent variants found in Ashkenazi Jews, it is possible
for a Jewish individual to have a different mutation in BRCA1/BRCA2 or in another gene that increases their risk for
cancer. Individuals with a significant personal or family history of cancer
should consult with a genetic counselor or healthcare provider about more
comprehensive testing options, as a negative 23andMe result does not eliminate
the possibility of a different genetic mutation.
- Those who receive
positive test results without assistance from a genetic counselor or qualified
physician are not likely to have adequate preparation to understand their risk
or evaluate appropriate preventative measures.
Those who receive
negative test results may not understand their remaining risks for hereditary
or non-hereditary cancer. Only about 10% of cancers are directly linked to
mutations such as those found in the BRCA1/BRCA2
genes. Some cancer is familial, but most cancer (about 70%) is sporadic, with
no directly traceable genetic or familial component. A negative test result alone
says very little about an individual’s ultimate risk for cancer.
In almost all cases,
physicians and genetic counselors who see patients regarding DTC results will
and should recommend that patients get more comprehensive testing.
For individuals who have
concerns about their hereditary cancer risk, we recommend:
- Meet with a genetic counselor,
or with a physician or health care provider involved with cancer treatment
- Discuss with that professional
your personal and family history of breast, ovarian, and other cancers,
what testing results can and cannot reveal, and the options that exist if
a test reveals a mutation that increases risk for cancer.
The Norton &
Elaine Sarnoff Center for Jewish Genetics offers a wealth of resources for persons
who want to learn more about their risk and options for testing, prevention,
and early detection. These resources include information on our website,
JewishGenetics.org, and community access to a genetic counselor who is
available to speak with concerned community members, provide education, answer
questions, and direct individuals to appropriate clinical resources.