Genetic testing gives people the chance to learn if their family history of breast cancer is due an inherited gene mutation, such as a BRCA1 or BRCA2 mutation. Only five to 10 percent of breast cancers in the U.S. are linked to a high risk genetic mutation [4]. For those who have these mutations, the risk of breast cancer is greatly increased. In these cases, there are certain steps that people can take to try and decrease this risk. Learn more about BRCA1 and BRCA2 mutations and breast cancer risk.
Who should consider testing?
Genetic testing for BRCA1 and BRCA2 is marketed as BRCAnalysis®. Although it is widely advertised, genetic testing is only recommended for certain people, including those with:
- A strong family history of breast cancer at an early age
- A family history of breast and ovarian cancers
- A family history of male breast cancer
- Ashkenazi Jewish heritage (who also have some family history of breast or ovarian cancer)
- A personal history of breast cancer at an early age
If you or an immediate family member is the only person in your family with breast cancer, it is unlikely that your family carries a BRCA mutation.
Although BRCA testing requires just a blood sample, the risks and benefits should be considered before being tested. There is a potential physical, emotional and financial impact of knowing your genetic status. Therefore, testing for the BRCA mutation is recommended only for families with a strong history of breast cancer.
Testing is first done on the family member with breast cancer. If no mutation is found, the cancer was probably not due to a genetic mutation and there is no need to test other family members. If a mutation is found, other family members can be tested for the specific BRCA mutation that was found.
Of the genes linked with breast cancer, BRCA1/2 mutations are the most well-known. Inherited mutations in the genes p53 and PTEN/ MMAC1 also increase breast cancer risk. Other genes are being studied for their possible role in breast cancer risk. Testing exists for some of these mutations, but is not often done because the mutations are much more rare than those in BRCA1/2 genes.
A health care provider or genetic counselor can talk with you about the issues related to genetic testing. For more information, visit the National Cancer Institute's genetic testing Web site at http://www.cancer.gov or call its hotline at 1-800-4-CANCER.
Genetic test results
Results from a BRCA test show whether or not there is a mutation related to cancer in the BRCA1/2 genes. There are three possible results from BRCA testing:
- no mutation (negative)
- a mutation linked to cancer (positive or carrier)
- a mutation that is not currently known to increase breast cancer risk (called variant of uncertain significance)
Having a BRCA1/2 mutation does not mean that you are certain to get breast cancer. And, not having a mutation does not mean you will never get breast cancer; you are still at some risk. If you do have a BRCA1/2 mutation, then there are steps you can take to lower your risk of breast cancer. You should discuss these steps with your health care provider. For more on this, visit the Early Detection and Screening chapter. No matter your mutation status, you can take steps to lower your breast cancer risk. Learn more about healthy lifestyle and prevention.
Psychological/emotional risks of genetic testing
If you are thinking about genetic testing, consider the emotional impact of the test results. For some people that carry a mutation, the knowledge can cause a lot of worry and anxiety even though they may never get breast cancer. On the other hand, if you do not have a mutation, you may feel a false sense of security about not being at risk. And, if you have a variant of uncertain significance, not knowing whether the mutation may increase your risk can add to the stress of an already trying process.
No matter the test result, it is important to follow breast cancer screening guidelines. There are special guidelines for those with a BRCA1/2 mutation and for those with no genetic mutations but with other factors that greatly increase risk. Talking with a genetic counselor or health care provider can help you understand your risk of breast cancer and make a breast health plan.
Genetic testing may also have an emotional impact on family members. For some people, finding out about a BRCA1/2 mutation also may affect their siblings and children, possibly causing them worry and anxiety.
Other risks of genetic testing
Genetic testing should be private. There are state and federal laws to protect against genetic discrimination. The Genetic Information Nondiscrimination Act (GINA) went into effect in May 2009. GINA prevents health insurers from denying coverage or charging higher premiums when a person's genetic profile puts them at higher risk for certain health conditions. GINA also protects against genetic discrimination from employers.
There have been no court cases of genetic discrimination regarding the BRCA1 and BRCA2 gene mutations since these tests have been used.
Benefits of testing
Finding out your genetic status through a genetic test can help you to make a breast health plan. If there is a mutation, you may reduce your chances of getting breast cancer by:
Learn more about options for women at high risk.
Knowing if you carry a mutation allows you to be screened at a younger age and more often. Breast MRI is now recommended for screening BRCA1 and BRCA2 carriers. MRI appears to be better than mammography at finding breast cancer in women with these mutations.
BRCA1 and BRCA2 carriers also have a higher risk of ovarian cancer. Women who know they have a mutation may consider screening and prevention options, such as oophorectomy), to reduce the risk of ovarian cancer. Learn more about prophylactic oophorectomy. The organization FORCE has on-line support for women affected by hereditary breast and ovarian cancer.
Getting genetic testing also lets you share your test results with family members, who may benefit from them. Other benefits of knowing genetic status include the chance to join breast cancer research studies on new prevention methods. To search for clinical trials recruiting those with BRCA1/2 or other genetic mutations, visit http://breastcancertrials.org or the National Institutes of Health Web site at http://clinicaltrials.gov.
Updated 11/10/09
