View Providers
BRCA1 and BRCA2 are genes that normally help reduce your risk of cancer by repairing damaged DNA in your cells. However, if these genes have a defect, called a mutation, DNA does not get needed repairs. As a result, your cells start accumulating damaged DNA, which increases your risk of developing certain cancers. Mutations in the BRCA1 and BRCA2 genes can increase the risk of breast cancer as well as ovarian cancer.
Inheriting BRCA Mutations
Getting tested for BRCA mutations could be important if you have breast cancer or if breast cancer runs in your family. BRCA mutations are associated with 5 to 10 % of all breast cancers. If your mother had breast cancer linked to a BRCA mutation, you have about a 50% chance of carrying the gene. If you inherited a BRCA gene mutation, your risk of developing breast cancer by age 70 is 45 to 65%. The BRCA1 mutation in women carries a higher risk of breast cancer than the BRCA2 mutation.
Should You Get Tested?
If you already have breast cancer, testing may be important. There is some evidence that BRCA gene mutations make it more likely you will have cancer in your other breast or that cancer will come back after treatment. If you don't already have breast cancer, you may want to test to see if you're at risk.
Reasons to consider testing:
-
You or someone in your family (parent, child, sibling, grandparent, uncle, aunt, nephew, niece, or first cousin) have or had breast cancer before age 50.
-
You or someone in your family have or had cancer in both breasts.
-
You or someone in your family have or had both breast and ovarian cancer.
-
Someone in your family is known to have a BRCA mutation.
-
A male member of your family has or had breast cancer.
-
You are of Eastern European Ashkenazi Jewish ancestry. BRCA1 and BRCA2 mutations are more common in this population compared to the general population.
Before you test, consider talking to a genetic counselor. The counselor can discuss the emotional, financial and medical concerns you may have to deal with if you have a BRCA gene mutation.
When possible, it may be best to have a family member with breast or ovarian cancer tested for a BRCA gene mutation first. If your family member does not have the mutation, you may not need the test yourself. But, if your family member has the mutation, you and other members of your family may want to be tested.
The Test and Its Results
The test for BRCA mutations is usually a blood test. The results come back in a few weeks.
-
A positive test means you have a BRCA gene mutation already known to increase the risk of breast cancer. That means that you, and possibly other family members, are at a higher risk for breast cancer than the general population.
- A negative test means that you probably do not have a higher risk than others do for this particular type of breast cancer.
Be aware that there is some margin of error in test results. Also, some results are "uncertain"—neither positive nor negative. For instance, the BRCA1 or BRCA2 gene may have a mutation, but the specific change has not previously been shown to increase a person’s risk of cancer.
What If You Test Positive?
If you test positive, talk with your genetic counselor about what that means for you and your family. If you already have breast cancer, talk with your doctor about the best treatment for you. You may decide to treat your cancer differently.
If you don’t have breast cancer, you may want to take certain steps:
-
Your doctor may suggest earlier and more frequent breast cancer screening tests to find evidence of breast cancer at an early stage.
-
You may decide to have your breasts removed before any breast cancer develops. This is called a prophylactic mastectomy. This type of surgery greatly reduces your risk of breast cancer. You may also decide to have your reproductive organs—including your ovaries—removed via a hysterectomy. This may also reduce your cancer risk.
-
Your doctor may recommend that you take a medication to reduce your risk of breast cancer. Tamoxifen and raloxifene are two examples.
The Bottom Line
The test for BRCA gene mutations is simple. The decision to test or not to test can be difficult. There are plusses and minuses to consider. The right answer varies from person to person. Most experts agree that the best way to start is to talk to your doctor and a genetic counselor. Gathering information from them will help you make this important decision.