Genetic testing for inherited mutations

Most people diagnosed with breast cancer have no family history of the disease. It happens by chance. But some people carry a genetic change passed down by a parent that increases the risk of breast cancer. This is called an inherited genetic mutation.

Genes are pieces of our DNA that give directions to cells. When genes work properly, they support healthy, functional cells in our bodies. If there is an error in the DNA, a mutation can happen.

Inherited genetic mutations can cause hereditary breast cancer. But most breast cancers are not hereditary. It is more common for non-inherited, or acquired, mutations to lead to breast cancer. Only about five to 10% of all breast cancers are linked to inherited gene mutations.

If you’ve been diagnosed with breast cancer, it’s important to know that:

• A breast cancer diagnosis does not always mean you carry an inherited genetic mutation.
• Most women diagnosed with breast cancer do not have inherited genetic mutations.
• Men diagnosed with breast cancer are more likely to carry an inherited genetic mutation.

If you learn through genetic testing that you carry an inherited genetic mutation, there are options for treating the current breast cancer and reducing the risk of future breast cancers.

Knowing whether you have an inherited genetic mutation can:

• Help you and your doctor choose the most effective treatments for you
• Help you, your family, and your healthcare team make decisions about screening to reduce the risk of a future cancer

If you have never been diagnosed with breast cancer but worry that you may be at increased risk due to an inherited genetic mutation, visit At high risk for breast cancer.

Inherited versus non-inherited gene mutations

Genetic mutations occur in one of two ways: by being passed on to us by our parents, or by developing on their own throughout the course of our lives.

Inherited genetic mutations are passed on by a parent.

• A person is born with this kind of mutation.
• Tests for inherited genetic mutations are typically performed on non-cancer cells such as blood or saliva. A sample is taken and sent to a lab, and the results show whether you carry a known inherited breast cancer gene mutation.

Non-inherited genetic mutations develop on their own, after a person is born. They are sometimes called acquired genetic mutations, somatic mutations, or sporadic mutations. Non-inherited genetic mutations:

• Do not come from your parents and cannot be passed on to your children
• Often form during cell division and multiplication—they are simply mistakes made during the process
• Can sometimes be caused by things in the environment, such as high levels of radiation, but finding their cause is not always possible
• Are a more common cause of cancer than inherited mutations

For people diagnosed with breast cancer, tests can confirm a non-inherited genetic mutation using a sample of tumor tissue or blood.

Knowing if you have an inherited or non-inherited genetic mutation can help you and your care team develop a plan to treat a current cancer or lower the risk of future cancer.

Inherited genetic testing versus genomic testing

You may have heard the term “genomic tests.” It’s important to know that tests for inherited genetic mutations and genomic tests are not the same thing. In breast cancer, genomic tests look at genes in cancer cells for different reasons:

• In early-stage breast cancer, genomic tests look at how gene activity affects the risk of recurrence. These tests are performed on tumor tissue. Learn more about genomic testing in early-stage breast cancer.
• In metastatic breast cancer, genomic tests look at whether there are non-inherited mutations that can be matched with a targeted treatment. These tests often use a technology called next-generation sequencing, which looks at hundreds of genes in tumor tissue or blood.

A genomic test is one of many types of biomarker tests. Learn more about biomarker testing.

Both genetic tests and genomic tests are an important part of personalized medicine, an approach to healthcare that looks at each individual person’s test results, day-to-day life habits, and environment to make decisions about treatments, lifestyle changes, and cancer screening schedules. With this approach, doctors can ensure the most precise treatment and avoid overtreatment.

Inherited gene mutations that increase breast cancer risk

There are several inherited gene mutations that increase the risk of breast cancer. Some are more likely than others to lead to cancer.

Finding out you have an inherited gene mutation linked to cancer can change how frequently you have screening tests. In some cases, an inherited gene mutation can open up new treatment options.

BRCA1 and BRCA2 genetic mutations are the two mutations most associated with hereditary breast cancer. Only a small percentage of all breast cancers are thought to be caused by BRCA mutations. These mutations can also increase the risk of ovarian cancer. Visit Inherited BRCA mutations to learn more, including:

• Signs breast cancer may be BRCA-related
• Understanding BRCA genetic test results
• How a positive result impacts treatment decisions

BRCA1 and BRCA2 mutations are not the only mutations linked to an increased risk of breast cancer. Mutations in the following genes can increase the risk of breast cancer, breast cancer recurrence, and for some, breast cancer developing in the opposite breast:

• ATM
• BARD1
• CDH1
• CHEK2
• PALB2
• PTEN
• RAD51C
• RAD51D
• STK11
• TP53

Learn more about these mutations on the Understanding genetic test results page.

Who should be tested?

For BRCA1 and BRCA2 mutations, the American Society of Clinical Oncology (ASCO) recommends testing if you:

• Are newly diagnosed or were treated for breast cancer in the past and are 65 or younger
• Are older than age 65 and have a personal or family breast cancer history suggestive of an inherited gene mutation (such as triple-negative breast cancer) or are of ancestry with known higher incidence of inherited genetic mutations, such as Ashkenazi Jewish ancestry
• Are 65 or older and meet eligibility requirements to take PARP inhibitor breast cancer treatment
• Have a second breast cancer diagnosis that is not a recurrence of a first breast cancer
• Have breast cancer and are assigned male at birth

ASCO also recommends that certain people be tested for inherited mutations in other genes, including CDH1, PALB2, PTEN, STK11, and TP53, if it can help inform treatment decisions, manage the risk of a new cancer, and confirm personal and family risk.

Read the full ASCO guidelines for genetic testing in people with breast cancer.

The National Comprehensive Cancer Network (NCCN) recommends genetic testing for mutations of BRCA1, BRCA2, CDH1, PALB2, PTEN, STK11, and TP53 if you:

• Have a personal history of breast cancer and are age 50 or younger
• If you are any age and:
  • Have a family history that includes close blood relatives with breast cancer at age 50 or younger, male breast cancer, ovarian cancer, pancreatic cancer, or certain prostate cancers
  • May be eligible for PARP inhibitor treatment
  • Have had a second breast cancer diagnosis that is not a recurrence of a first breast cancer
  • Are a man diagnosed with breast cancer
  • Have triple-negative or lobular breast cancer plus a personal or family history of a certain type of stomach cancer
  • Are of Ashkenazi Jewish ancestry

Read the complete NCCN guidelines for genetic testing in people with breast cancer.

Having a family member who carries a gene mutation greatly increases the chance that you also carry a gene mutation. Your test results may help other relatives including parents, siblings, children, grandchildren, or cousins decide whether they should seek genetic counseling to discuss possible testing.

Should I consider genetic testing for an inherited mutation?

A genetic counselor can help you understand whether your family history increases the chance that you may have an inherited genetic mutation. Consider meeting with a genetic counselor if any of the ASCO or NCCN guidelines above apply to you.

If your doctor does not talk with you about genetic counseling or testing, it’s OK to start the conversation yourself and ask for a referral to a genetic counselor. Learn more about genetic counseling.

Re-testing if you had testing in the past

If you were tested for an inherited gene mutation many years ago, ask your doctor or genetic counselor if getting tested again would be beneficial for you. Today’s genetic tests can look for more mutations in more genes than they could a decade ago. It’s possible current tests may show you carry a gene mutation that was unknown before, especially if your past results were uncertain.

Types of genetic tests

There are several types of tests to search for inherited mutations that can cause breast cancer. Testing can be done in a few different ways. Your genetic counselor can explain which type of testing is best for you.

Depending on your personal and family history of cancer, and whether a gene mutation has been identified in your family in the past, your counselor may recommend testing of BRCA1 and BRCA2. They may also recommend testing for other genes or for a panel of genes.

The three most common tests are:

• Comprehensive testing of BRCA1 and BRCA2 with the option of including PALB2
• Single-site or single-gene testing for a mutation already known to be in your family
• Gene panel tests, which look for many mutations in many genes all at once; these tests can focus on genes associated with breast cancer or genes associated with breast and other cancers

How genetic testing works

If you’ve been diagnosed with breast cancer, talk with your oncologist about genetic counseling and testing and whether it may be helpful for you.

Deciding to get genetic counseling

Genetic counseling is not required to get genetic testing for an inherited mutation. But meeting with a genetic counselor is an important and helpful way to think through whether your personal or family history of breast cancer suggests genetic testing is right for you.

Genetic counselors are professionals trained in risk assessment and in explaining your test results. They can also:

• Talk with you about how to share test results with your family
• Provide guidance on talking with your oncologist about managing risk

If your doctor hasn’t referred you to a genetic counselor, ask to be referred. It's also possible to meet with a genetic counselor without a doctor giving a referral, but it’s important to check with your insurance company first. In some cases, your insurance won’t cover counseling services unless a doctor submits a referral.

You can meet with a genetic counselor in person if they’re available in your area. Many hospitals also have options to meet a genetic counselor by phone or video appointment (telehealth).

To find a genetic counselor in your area or a genetic counselor who can offer telehealth services, visit the National Society of Genetic Counselors website.

If genetic counseling is not available to you, your oncologist can order genetic testing for you. Some oncologists have additional training in reading genetic test results.

Informed consent for genetic testing

If you decide to move forward with genetic testing for an inherited mutation, you’ll be asked to give informed consent before the test.

To give informed consent, you’ll sign a form that says:

• You understand the genetic testing process and that you had the opportunity to ask questions.
• You understand that you have a choice about whether you get the test.

To learn more about the informed consent process, visit The American Cancer Society.

Giving a blood or saliva sample

After you sign the genetic testing informed consent form, you will provide a blood or saliva sample.

Genetic testing with a blood sample: Blood may be drawn at a lab or at your doctor’s office or a hospital, and then sent to a lab for testing. The blood is taken by needle, usually from a vein on the inside of your elbow.

Genetic testing with a saliva sample: If you are offered a saliva collection kit, you will collect your sample on your own, at home. You will spit into a cup after following instructions provided to you and then mail the sample to the lab or drop it off at your doctor’s office for them to send on your behalf.

The lab will then search for gene mutations.

Getting genetic test results

A results report will be sent to your doctor or genetic counselor. It may take several weeks for your test results to come back. If you need your results sooner to make treatment decisions, ask your healthcare team if they can rush the results.

When your care team receives your test results, they’ll schedule time to talk with you about what they mean and how they may impact treatment, screening schedules, and lowering the risk of future cancers. Make sure to ask for a copy.

Learn more about Understanding genetic test results.

Sharing results with family

Sometimes, family dynamics can make it hard to discuss topics like possible shared inherited gene mutations. For tips on how to share test results with family, visit Sharing your inherited genetic test results.

Paying for genetic testing

The cost of genetic testing for an inherited mutation can be different depending on the mutation and your insurance coverage.

Paying for inherited BRCA mutation testing

Under the Affordable Care Act, most private insurance companies are required to pay the total cost of BRCA testing for people who meet eligibility requirements, with no out-of-pocket costs. If you don’t fully meet the requirements needed under the ACA, many insurance companies will still pay a portion of the cost, and you will pay some out-of-pocket fees.

If you have Medicaid or Medicare, the requirements for coverage are different. Your genetic counselor can review the cost of testing with you before you have the test.

If you don’t have insurance or insurance won’t cover the cost of testing, paying out-of-pocket for BRCA testing can cost $250 or more. Some labs and cancer centers offer financial assistance or payment plans to people who are uninsured. Be sure to ask your genetic counselor for help with these resources.

Paying for other inherited mutation testing

The Affordable Care Act does not require insurers to help pay for genetic testing to look for inherited mutations in non-BRCA cancer-related genes, such as CDH1, PALB2, and PTEN—even though they are included in testing guidelines. Still, it’s possible your insurance will help cover some of the cost. Talk to your genetic counselor and call your insurance company to find out.

Family members’ genetic testing costs

If you test positive for an inherited high-risk cancer mutation, your family members’ insurance providers may be more likely to cover the cost of their genetic testing. If family members are interested in testing, encourage them to check with their health insurance companies about coverage.

To learn more about financial support and paying for care, visit Financial matters.

How clinical trials can help if you test positive

If you test positive for an inherited genetic mutation and decide to participate in a clinical trial studying the mutation, you may be able to have low- or no-cost access to a new treatment. You can also help researchers:

• Understand more about how mutated genes can lead to breast cancer
• Develop new breast cancer treatments targeted to cancers in people with inherited mutations

Learn more about participating in clinical trials.

A note on at-home testing

You may see at-home genetic tests advertised on TV or available online. They can be delivered directly to you by mail and don’t need to be ordered by a doctor or other healthcare professional.

An at-home genetic test may require you to visit a health clinic to have a blood sample taken and sent to the lab that sells the test, or it may only ask you to send a saliva sample to the lab by mail, without seeing a doctor first.

An at-home test may cost less or feel like less of a burden because it requires fewer doctor appointments. But if you choose at-home testing, you won’t have guidance from a genetic counselor.

Having a genetic counselor ensures that:

• You’re getting the right tests for your risk profile.
• You know the next steps if you test positive for a gene mutation.

Genetic counselors are also trained in helping you navigate emotions that may come up once your results are back, and in helping you prepare to share your result with family if you choose to do so.

If you have questions or concerns about at-home testing versus testing at your hospital, talk with your oncologist, or ask to speak with a social worker, genetic counselor, or patient navigator.