Testing for Hereditary Breast and Ovarian Cancer

Why get tested

Genetic testing for hereditary breast and ovarian cancer can help you better understand and manage your risk for breast, ovarian, and other cancers. Finding out that you have a BRCA1, BRCA2, or other mutation that makes you more likely to develop breast, ovarian, and other cancers can help you decide what medical options to take to prevent cancer or find it early. If genetic testing shows that you did not inherit the mutation that runs in your family, you might not need to have screenings beyond what is recommended for the general public. Genetic counseling before genetic testing for hereditary breast and ovarian cancers is important to determine whether you and your family are likely enough to have a mutation that it is worth getting tested.

Who should be tested

Usually, genetic testing is recommended if you have:

• A strong family health history of breast and ovarian cancers
• A moderate family health history of breast and ovarian cancers and are of Ashkenazi or Eastern European Jewish ancestry
• A personal history of breast cancer and meet certain criteria (related to age of diagnosis, type of cancer, presence of certain other cancers or cancer in both breasts, ancestry, and family health history)
• A personal history of ovarian, fallopian tube, or primary peritoneal cancer
• A known BRCA1, BRCA2, or other inherited mutation in your family

The genetic counselor can help you determine the best testing strategy for you and your family. Whenever possible, the first person tested in your family should be someone who has had breast, ovarian, or another BRCA-related cancer.

Types of tests

Genetic testing for hereditary breast and ovarian cancers looks for mutations in the BRCA1 and BRCA2 genes. Your healthcare provider might suggest testing using a multigene panel, which looks for mutations in several genes at the same time, including BRCA1 and BRCA2. If you are of Ashkenazi or Eastern European Jewish ancestry, your healthcare provider might suggest testing for three specific BRCA1 and BRCA2 mutations, called founder mutations. These are the most common mutations in people of Ashkenazi or Eastern European Jewish ancestry.

Testing results

Genetic counseling after genetic testing is important to help you understand your test results and decide the next steps for you and your family:

Positive test result

The test showed that you have a mutation known to cause hereditary breast and ovarian cancers.

What it means for you

• You can take steps to make it less likely that you will get cancer or to find cancer early if you do get it.
• If you have already had breast or ovarian cancer, a positive test result can help guide your treatment decisions.

What it means for your family

• If other family members decide to get genetic testing, their test should check for the same mutation you have.
• Your parents, children, sisters, and brothers each have a 1 in 2 (50%) chance of having the same mutation.

Negative test result

The test didn't find a mutation. However, what this means for you depends on whether you have already had breast or ovarian cancer and whether another relative is known to have a mutation.

If you have already had breast or ovarian cancer

What it means for you

• A negative result means that the test did not find a mutation that caused your cancer.
• Further testing might be available.

What it means for your family

• The breast and ovarian cancers in your family are less likely to be due to an inherited mutation, unless another relative is known to have a mutation.
• Genetic testing in your family members who have not had breast or ovarian cancer is unlikely to be helpful, unless another relative is known to have a mutation.
• In some cases testing might still be helpful for another family member who has had breast or ovarian cancer. This is because it is still possible that there is an inherited mutation in your family, but you did not inherit it.

If you have not had breast or ovarian cancer

What it means for you

If a mutation has not already been found in another family member

• A negative test result is considered uninformative because the result could mean that the breast and ovarian cancers in your family are caused by one of the mutations included in the genetic test but you did not inherit the mutation OR the breast and ovarian cancers in your family were not caused by a mutation that was included in the genetic test.
• You are still considered at increased risk for the cancers that run in your family. The level of risk, appropriate screening and prevention options, and need for additional genetic testing will vary for each person and each family.

If a mutation has already been found in another family member and the test showed you do not have the mutation

• You are not at higher risk than the average person for breast or ovarian cancer. You also cannot pass the mutation on to your children.

Variant of uncertain significance (VUS) result

The test found a mutation in one of the genes associated with hereditary breast and ovarian cancers, but whether that specific mutation causes cancer is unknown. Some mutations prevent genes from working properly, while others have no effect. It is not always easy to tell whether or not a mutation in a gene has a harmful effect.

What it means for you

• If you have already had breast or ovarian cancer, it is unclear whether the mutation found in the test caused your cancer. Further testing might be available.
• Whether or not you have already had breast or ovarian cancer, you are still considered at increased risk for the cancers that run in your family. The level of risk, appropriate screening and prevention options, and need for additional genetic testing will vary for each person and each family.

Having a strong family health history of breast and ovarian cancers does not mean that you definitely have an inherited mutation. In fact, most women identified as being at increased risk for BRCA1 and BRCA2 mutations based on family health history do not have BRCA1 or BRCA2 mutations.

Using family health history information will not find everyone with BRCA1 or BRCA2 mutations. Not everyone with a BRCA1 or BRCA2 mutation has a strong family health history of breast and ovarian cancers. Some even have no known family health history of breast and ovarian cancers.