BRCA Testing

Is Testing Right for Me? I Have My Test Results

BRCA Testing

What Is BRCA1 and BRCA2 Mutation Testing?

Most cancer happens by chance. Just 5% to 10% of breast and ovarian cancers are caused by inherited gene mutations. Most of these are caused by a mutation in one of the BRCA genes, called BRCA1 or BRCA2.

These genes are found in every cell in each person's body. Their job is to protect the cell's DNA from damage. If someone has a mutation in one of these genes, the risk to develop breast and ovarian cancer is higher. Both women and men can pass down BRCA mutations to their children.

Having a BRCA mutation doesn't mean that you will automatically develop breast or ovarian cancer. But, it does increase your risk for these cancers. Each person's risk depends on many factors, and a BRCA mutation is a strong risk factor. There are genetic tests that look for these mutations in high-risk people.

If you have a BRCA mutation, you can:

  • Take steps to lower your chance of developing cancer
  • Work with your doctor to create a plan for early detection and risk reduction
  • If you are diagnosed with cancer, decide on the most effective treatments
  • Help your family members know their own risk by sharing your test result with them

 

Next: Who Is at Risk for a BRCA Mutation?

Why are you considering genetic testing? Check only one at a time.

I have a family member who had genetic testing that found a BRCA mutation.

I have a history of cancer that suggests I might have a BRCA mutation, but no one in my family has had genetic testing before. (See signs of BRCA-related cancer)

I haven't had cancer, but my family history suggests a BRCA mutation. No one has had genetic testing yet.

None of these

Are you Ashkenazi Jewish?

Yes

No

BRCA mutations that increase the risk of breast and ovarian cancer are inherited. If you have a family member with a BRCA mutation, you’re at-risk for having that mutation, too. How high your risk is depends on how closely you are related to this person. You should review your family history with your doctor to discuss genetic testing and cancer screening.

Because of your family risk, you may need extra, earlier screening for cancer. The only people who can safely avoid high-risk screening are those who can confirm that they don't have the family mutation.

Since a BRCA mutation has been found in your family, you and other relatives can test for that mutation. The mutation in your family is probably one of three that are most common in Ashkenazi Jewish people. These are named after their location on the gene: 187delAG (BRCA1), 5385insC (BRCA1), and 6174delT (BRCA2).

These three mutations are usually tested together ("multisite testing"). If you choose to have testing, experts recommend testing for all three — even when you already know the family mutation. Because they are so common in Ashkenazi Jewish people, it’s possible for more than one mutation to be run in a family.

If the mutation in your family isn't one of the Ashkenazi Jewish mutations, experts recommend both multisite testing for the Ashkenazi Jewish mutations and single site testing for the family mutation. To perform single site testing, the laboratory needs the exact name of the family mutation. If possible, give the lab a copy of the family member's genetic test results.

  • If testing finds the mutation that runs in your family, you can be sure you have an inherited risk for breast and ovarian cancer. This doesn't mean that you will definitely get cancer, but the risk is high enough that you need early and regular screening to catch a cancer if it does develop.
  • If testing doesn't find a mutation, you can be sure that you didn't inherit the mutation that runs in your family. Unless you have other risk factors, you won't need the extra cancer screening recommended for people at high risk. You can now have general screening for people at average risk.

BRCA mutations that increase the risk of breast and ovarian cancer are inherited. If you have a family member with a BRCA mutation, you’re at-risk for having that mutation, too. How high your risk is depends on how closely you are related to this person. You should review your family history with your doctor to discuss genetic testing and cancer screening.

Because of your family risk, you may need extra, earlier screening for cancer. The only people who can safely avoid high-risk screening are those who can confirm that they don't have the family mutation.

Since a BRCA mutation has been found in your family, you and other relatives can test for that one mutation. Testing for one mutation is cheaper and more accurate than full gene sequencing (also called "comprehensive analysis"). To perform this test, the laboratory needs to know the exact name of your family's mutation. If possible, give the lab a copy of the relative's genetic test results.

  • If testing finds the mutation that runs in your family, you can be sure you have an inherited risk for breast and ovarian cancer. This doesn't mean that you will definitely get cancer, but the risk is high enough that you need early and regular screening to catch a cancer if it does develop.
  • If testing doesn't find the mutation, you can be sure that you don't have the mutation that runs in your family. Unless you have other risk factors, you won't need the extra cancer screening recommended for people at high risk. You can now have general screening for people at average risk.

Anyone with a personal cancer history that suggests a BRCA mutation can consider BRCA testing. (See guidelines for who should consider BRCA testing here.)

The first person tested has full gene sequencing (also called "comprehensive analysis"). Sequencing looks at the BRCA1 and BRCA2 genes "letter-by-letter" to find any changes. If the test is normal, the laboratory looks to see if there are large extra or missing parts of the gene. This kind of testing is expensive and time-consuming, but it will find a BRCA mutation over 90% of the time if you have one.

  • If testing finds a mutation, this most likely explains your cancer history. You also have a higher chance for another breast or ovarian cancer in the future. This information can help you and your doctor decide on the best cancer treatments and plan future prevention and screening.

    Family members who want to know about their risk can now have single site genetic testing to look for the mutation you have. This kind of testing is less expensive and more accurate than full gene sequencing.
  • If testing doesn't find a mutation, this doesn't rule out a mutation. It's possible to have a BRCA mutation the test can't find. It's also possible to have a mutation in another gene that can cause breast or ovarian cancer.

    BRCA testing won't be useful for your family members, unless another relative has more signs of a BRCA-related cancer than you. Given your history of cancer, your family should have early and extra screening for cancer.

Any Ashkenazi Jewish person who's had cancer of the breast, ovary, fallopian tube, or peritoneum (the thin lining inside the abdomen) can consider BRCA testing.

Three BRCA mutations cause most of the inherited breast and ovarian cancers in Ashkenazi Jewish people. These mutations are named after their location on the gene: 187delAG (BRCA1), 5385insC (BRCA1) and 6174delT (BRCA2). If you choose to have testing, experts recommend you test for these mutations first ("multisite testing"). Testing for three mutations is much faster and cheaper than full gene sequencing.

  • If testing finds a mutation, this most likely explains your cancer history. You also have a higher chance for another breast or ovarian cancer in the future. This information can help you and your doctor decide on the best cancer treatments and plan future prevention and screening.

    Family members who want to know about their risk can now have testing to see whether or not they have inherited the family mutation.
  • If testing doesn't find a mutation, the results don't rule out a BRCA mutation. If your personal or family history strongly suggests a BRCA mutation, your doctor or genetic counselor might recommend doing full gene sequencing next.

    Multisite testing may not be useful for your family, unless another relative has a more signs of a BRCA-related cancer than you or cancers on the other side of their family. Given your history of cancer, your family members may still need to have early and extra cancer screening.

People with enough signs of inherited cancer in their family can consider BRCA testing. (See guidelines for testing here.)

However, you may not be the best person in your family to test first. If possible, the first person tested should be someone who's had breast or ovarian cancer, because they will be most likely to turn up a mutation if there is one running in the family

Genetic testing can't find all possible BRCA mutations. Testing someone who is most likely to have a mutation first, such as someone who's had breast cancer, will give your family the most information. If a mutation is found in that person, other family members can have single site testing for just the family mutation. If a mutation isn't found in that person, then it's likely that the family’s cancers are caused by something else. BRCA testing won't be useful for anyone else in the family.

If the person who is the best fit for testing has passed away, it may be possible to test stored DNA. For example, tissue from tumors is usually stored for several years and may be available for testing.

The first person in your family to test should have full gene sequencing, which looks at the BRCA1 and BRCA2 genes "letter-by-letter" to find any change. If this test is normal, the laboratory looks for any large extra or missing parts of the gene. This kind of testing is expensive and time-consuming, but it will accurately identify a BRCA mutation over 90% of the time if there is one.

If it isn't possible to test a relative who's had breast or ovarian cancer first, you can still have testing, but the meaning of your results may not be clear.

  • If you have testing and it finds a mutation, you have inherited a higher risk for breast and ovarian cancer. This doesn't mean that you will definitely get cancer, but your chances are higher than normal. You will need early and regular screening to check for cancer. You may also consider options — like surgery and drugs — that lower your risk or stop cancer from happening in the first place.
  • If you have testing and it doesn't find a mutation, there are two main reasons for this result. There is a BRCA mutation in your family, and either it can't be found with this test or you didn't inherit the mutation. There's no way to know which is true for you — and the two possibilities mean very different things for your risk. Since you may still have a high risk for cancer, you need to have extra cancer screening starting at a young age. A third possibility is that the cancer in your family is due to changes in other genes and/or other environmental factors. Testing a family member who's had cancer is still an option. If a mutation is found in that relative, it will clarify your results: You will not have the BRCA mutation that runs in your family.

People with enough signs of inherited breast or ovarian cancer in their family can consider BRCA testing. (See guidelines for testing here.)

However, you may not be the best person in your family to have testing first. If possible, the first person tested should be someone who's had breast or ovarian cancer, because they will be most likely to turn up a mutation if there is one running in the family.

Three BRCA mutations are most common in Ashkenazi Jewish people. These mutations are named after their location on the genes: 187delAG (BRCA1), 5385insC (BRCA1) and 6174delT (BRCA2). If you are Ashkenazi Jewish, you can have a test that just looks for these mutations ("multisite testing").

Genetic testing can't find all BRCA mutations. Testing someone who is most likely to have a mutation first, such as a person who's had breast cancer, will give your family the most information. If a mutation is found in that person, other family members can have testing for the family mutation and can be sure that the test will find the mutation if they have it. If a mutation isn't found in that person, then the same test won't be useful for other family members. If the person who would be the best fit for testing has passed away, it may be possible to test on stored DNA. For example, tissue from tumors is usually stored for several years and may be available for testing.

If it isn't possible to test a relative with breast or ovarian cancer first, you can still have testing, but your results may not be clear.

  • If testing finds a mutation, you inherited a high risk for breast and ovarian cancer. This doesn't mean that you will definitely get cancer, but your chances are higher than normal. You will need early and regular screening to check for cancer. You may also consider options — like surgery and drugs — that lower your risk or stop cancer from happening in the first place.
  • If testing doesn't find a mutation, there are two main reasons for this result. There is a BRCA mutation in your family, and either it can't be found with this test or you didn't inherit a mutation. There is no way to know which of these reasons is true for you — and the two possibilities mean very different things for your risk. Since you may still have a high risk for cancer, you need to have extra cancer screening starting at a young age. A third possibility is that the cancer in your family is due to changes in other genes and/or other environmental factors.

    No genetic test can find all of the gene changes that cause an inherited risk for breast or ovarian cancer. Since you may still have a high risk for cancer, you need to have extra cancer screening starting at a young age. Testing a family member with breast or ovarian cancer can clarify your results. If a mutation is found in that relative, it means you don’t have the mutation that runs in your family.

If none of these choices is true for you, BRCA genetic testing is unlikely to be useful.

Three BRCA mutations are most common in Ashkenazi Jewish people. So, people with Ashkenazi Jewish ancestry don't need as many signs of inherited cancer to make testing useful — but there do need to be some signs. Experts don't recommend BRCA testing just on the basis of Ashkenazi Jewish ancestry.

If none of these choices is true for you, BRCA genetic testing is unlikely to be useful.

People are sometimes offered BRCA testing, even if their personal or family cancer history isn't quite strong enough to meet the medical guidelines for testing. This may happen if you have some warning signs but know little about your family history, or you have such a small family that there aren't enough people to judge cancer risk, or you have ancestors from a place that has a higher risk for BRCA mutations (for example, Iceland, Sweden, and Hungary). These decisions are made on a case-by-case basis. Insurance is less likely to cover testing if your history doesn't meet testing guidelines.

There are many different causes of breast and ovarian cancer. Some are genetic, but most aren't. If you have cancer, a family history that concerns you, or another reason you think genetic testing could help you, talk to your doctor or a genetic counselor.