Breast Cancer (BRCA) Gene Test
A breast cancer (BRCA) gene test is a blood test to check for specific changes (mutations) in genes that help control normal cell growth. Finding changes in these genes, called BRCA1 and BRCA2, can help determine your chance of developing breast cancer and ovarian cancer. A BRCA gene test does not test for cancer itself. This test is only done for people with a strong family history of breast cancer or ovarian cancer, and sometimes for those who already have one of these diseases. Genetic counseling before and after a BRCA test is very important to help you understand the benefits, risks, and possible outcomes of the test.
A woman's risk of breast and ovarian cancer is higher if she has BRCA1 or BRCA2 gene changes. Men with these gene changes have an increased risk of breast cancer. And both men and women with these changes may be at an increased risk for other cancers.1 The gene changes can be inherited from either your mother's or father's side of the family.
Certain people have a higher chance of inheriting BRCA1 or BRCA2 gene changes.
If you don't meet any of these criteria, you are not likely to have a BRCA1 or BRCA2 gene change. Only about 2 out of 100 adult women have an increased risk of having a BRCA gene change.2
Health Tools help you make wise health decisions or take action to improve your health.
Why It Is Done
If your family history or personal history indicates a high chance for breast cancer, a BRCA gene test is done to check your chance of developing this cancer.
A BRCA gene test does not test for cancer itself. It is used to help women who have a strong family history of breast or ovarian cancer find out if their chance is high enough to think about prevention measures before cancer develops. These measures include:
Men with a family history of BRCA changes also may want to be tested to find their chance of breast cancer.
For a woman who has ovarian cancer, or for a man or a woman who has breast cancer, results from a BRCA gene test can help other family members know their chances of these and perhaps other cancers. If the person with breast or ovarian cancer has normal BRCA gene test results, family members probably would not benefit from the BRCA genetic test.
How To Prepare
Genetic counseling is strongly recommended before and after a BRCA test to help you understand the benefits, risks, and possible outcomes of the test. A BRCA test gives you the chance to make informed medical and lifestyle decisions. Genetic counselors are trained to talk with you about the test and its results, including the medical information and your emotional concerns.
This test may cause you some worry, both before and after the test. Talk with a genetic counselor before the test to help you prepare for and cope with this worry. Think about what you may do if your test is positive. For example, would you consider any prevention measures, such as the following:
You will be asked to sign a consent form that says you understand the risks of the test and agree to have it done.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, or how it will be done. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).
No other special preparation is needed before you have this test.
How It Is Done
The health professional drawing blood will:
How It Feels
The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.
It is common to worry before a BRCA test and while waiting for its results.
There is very little chance of a problem from having a blood sample taken from a vein.
Some women may be worried about the test results and how it will affect their life insurance, disability insurance, or long-term care insurance.
Normal (called negative)
No changes were found in the BRCA1 or BRCA2 genes.
A negative result and your overall family risk must be considered together.
Only about 5% to 10% of breast and ovarian cancers are linked to the BRCA1 or BRCA2 gene change. If you have a strong family history of breast or ovarian cancer, you may still have a higher chance of developing breast cancer even if you have a negative BRCA result. Other gene changes are possible that make cancer more likely.
Abnormal (called positive)
BRCA1 or BRCA2 gene changes are present.
Women who have BRCA1 or BRCA2 gene changes have about a 35% to 84% chance of developing breast cancer and between a 20% and 40% chance of developing ovarian cancer during their lifetimes.1, 3 These numbers show a wide range of chance and depend on your other personal and family history.
Men with BRCA1 changes have a higher risk of breast cancer and possibly other cancers, such as pancreatic, testicular, or prostate cancer. Men with BRCA2 changes have an increased risk of breast, pancreatic, and prostate cancers.1
Uncertain (called variant of uncertain significance or VUS)
This result may mean that a gene change is present but it is difficult for your doctor to know if the change is important and if it changes your chances of developing cancer.
What Affects the Test
Your doctor will talk with you about anything that may stop you from having the test or that may change the test results.
What To Think About
There are several important things to think about when you are making the decision to have a BRCA gene test.
Genetic counseling before and after a BRCA test will help you understand the benefits, risks, and possible outcomes of testing. A BRCA test gives you the chance to make informed medical and lifestyle decisions. To find doctors who do gene tests and counseling, call the cancer information service at the National Cancer Institute at 1-800-4-CANCER (1-800-422-6237). To find a genetic counselor near you, contact the National Society of Genetic Counselors at (312) 321-6834 or visit their website at www.nsgc.org.
Other Places To Get Help
eMedicineHealth Medical Reference from Healthwise
To learn more visit Healthwise.org