When Should You Get Genetic Testing for Breast Cancer?

More is known now than in the past about preventing cancer. Knowing your risk for breast cancer doesn’t determine your choices – testing helps you understand your risk factors and decide the best way to manage your health. Learn when genetic testing might benefit you.

Understanding Cancer Risk

A diagnosis of breast and other cancers often prompts people to learn more about their family histories, only to learn they have inherited a cancer susceptibility gene (a gene that, when changed, puts a person at increased risk for developing cancer).

“Still, only a minority of cancers are related to a hereditary syndrome. For example, in women with a diagnosis of breast cancer, less than 20% are related to a familial tendency,” said Dr. Grace Makari-Judson, Co-Director of the Rays of Hope Center for Breast Cancer Research.

A woman with an average risk of breast cancer has about a 12% chance of developing breast cancer in her lifetime, while a woman who has inherited a breast cancer susceptibility gene could have a 20-80% risk over her lifetime depending on the specific gene. Multigene panels are currently performed to include many cancer associated genes. These broader tests find more mutations, including the better-known BRCA1 and 2, but may also identify genes that do not have clearly recommended guidelines for care.

When testing large groups of genes, there is up to a 20-30% chance of having a “variant of uncertain significance” which is a genetic change that may or may not be associated with higher cancer risk. If a positive result is found in an individual, there is a 50-50 chance that it may be passed on to their children. Your grandmother, aunt and mother may have had breast cancer and tested positive for the gene. Still, you may not have inherited it.

Individuals with a cancer diagnosis should always test first, if possible. “This is important since the results may affect their own cancer treatment and would be informative for multiple family members,” says Makari-Judson. Testing is more complex today and interpretation of results and formulation of a plan are best done in consultation with trained professionals with a genetics or oncology background.

What is BRCA Testing?

A BRCA test is a blood test to find mutations (changes) in the BRCA1 or BRCA2 breast cancer susceptibility genes. BRCA genetic testing can help you and your provider understand your risk of developing breast cancer. Breast cancer genetic testing is usually done if you have a family or personal history of breast cancer, and not typically for people at average risk.

When Should You Be Tested for a BRCA Mutation?

BRCA gene testing is not usually recommended for people under age 18. Genetic counseling is important for figuring out whether or not you or a family member should be tested.

What to expect during genetic testing

1. Genetic counseling

Your genetic counselor will create a positive environment to explore your family history and attitudes toward cancer. A genetic counselor is trained to discuss these sensitive topics and help you understand your feelings and next steps.

During this meeting, you will:

• Discuss your family history in-depth.
• Talk about your health.
• Explore your choices and discuss next steps if your genetic test comes back positive for either gene.
• Discover your personal beliefs about health and illness. This discussion can help you mentally prepare to receive the results.
• Explore how you will communicate to relatives the risk factors associated with carrying the gene. 

2. Genetic testing options

Genetic testing for breast cancer can be performed as a blood test, a cheek swab or a saliva test. Talk with your care team about the types of testing you will need.

3. Informed consent

You sign documents relating to the topics you discussed with your genetic counselor. This step helps ensure that you understand all of the testing procedures and possibilities.

4. Results

Your genetic counselor should get the results in a few weeks and lets you know if a “known deleterious mutation”, meaning a genetic change associated with higher cancer risk, is identified. Testing results are sometimes unclear, so your genetic counselor helps you interpret the test and understand if it is “clinically significant” (meaning that it would change recommendations for care).

If you test positive for a breast cancer predisposing gene, it means you are more likely to get breast cancer than other women. Your care team will work with you on the best next steps. Options for preventing breast cancer or diagnosing it earlier include:

• Heightened surveillance including mammography and breast MRI
• Taking risk reducing medication
• Removing your breasts (mastectomy)
• Staying healthy and paying close attention to changes in your breasts

5. Communication

It is very important to keep a copy of your test report and to share it with your family.

Depending on your results, you may need to discuss next steps to manage your health. If a known mutation is found, it is helpful to meet with a medical oncologist to put this information into perspective with your age, overall health and family history. Strategies for those with positive tests may include preventative surgeries; heightened surveillance, risk reducing medications and lifestyle changes.

“A negative test does not mean that an individual will never be diagnosed with cancer, since most people with cancer test negative,” says Makari-Judson, “so it is important to keep up with regular screenings as recommended for people in your age group.”

Learn More

Information is power. Understanding your risk for breast cancer gives you the power to plan for how to take charge of your health. Talk to your healthcare provider about whether you should consider a consultation with the Family Cancer Risk Program.

For more information, call 413-794-8890.

Learn more about breast cancer awareness month.