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Considering New Direct-to-Consumer Breast Cancer Tests? First, Get the Facts

Tiffani A. DeMarco, MS, LCGC, is a licensed and certified genetic counselor and the manager of the cancer genetic counseling program at the Inova Translational Medicine Institute. She and her team of cancer genetic counselors specialize in counseling patients and family members at risk for hereditary cancers.

The U.S. Food and Drug Administration (FDA) recently gave approval for the direct-to-consumer genetic testing company 23andMe to test customers’ DNA for certain genetic changes associated with breast and ovarian cancers.

This announcement has received a lot of media attention. After all, it’s the first time a genetic test for cancer risk has been approved for sale directly to consumers – no prescription or doctor’s referral needed. But, many news stories have left out key details about who the test is most appropriate for and what the test can tell you.

If you’re considering sending a sample of your DNA for testing, there are some things you should know first.

BRCA Test: Limited Scope

Genetic testing can identify certain gene changes, or mutations, that are linked to an increased risk of cancer. Many different gene mutations are associated with cancers, and more are being discovered all the time.

Currently, 23andMe is authorized to test for three specific mutations found on the BRCA1 and BRCA2 genes. These genetic signatures are associated with a significantly greater risk of breast and ovarian cancer in women, as well as prostate cancer and male breast cancer.

These three mutations, however, are not very common. They are typically seen in people of Ashkenazi Jewish descent. In other ethnic groups, these mutations are rare.

What’s more, there are many other genes associated with breast and ovarian cancer risk, in addition to BRCA1 and BRCA2. By screening for just three mutations in two genes, the 23andMe test is extremely limited in scope.

Genetic Counseling: Being Proactive

As a genetic counselor, I have several concerns about direct-to-consumer tests like the one being sold by 23andMe. People who take the test and get a negative result might not realize how limited those results really are. They can have a false sense of security, when in fact they might benefit from more comprehensive genetic testing.

On the other hand, people who receive a positive test result can feel blindsided. 23andMe doesn’t offer any genetic counseling to help people make sense of the findings. People are often left scrambling to find a genetics professional or doctor who can explain what the test means – and help them decide what do to next.

Our approach to genetic testing is proactive rather than reactive. Our skilled genetic counselors talk to patients about their individual risk factors, including their personal and family history of cancer. Then we help them decide which tests make the most sense for them, and what a positive test might mean for patients as well as their family members.

When patients do receive a positive test result, we help them understand their options for managing their risk, and connect them to surgeons and cancer specialists who create a personalized care plan.

Guiding Health Decisions

Genetic testing for breast cancer isn’t recommended for everyone. But if you have had breast cancer (especially before age 50), have had ovarian cancer, or have had multiple relatives with breast cancer, we recommend genetic counseling.

Genetic testing can be a valuable source of information that can guide important health decisions. But the results of these tests can be confusing, and can have implications for your own medical choices and those of your family members. Fortunately, you don’t have to make sense of the science all by yourself.

The board-certified genetic counselors at the Inova Cancer Genetics Program are here to help patients navigate this complex medical information. To learn more or schedule an appointment, call 703-698-2491 or email us at cancergenetics@inova.org.

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