Test Overview
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.
- Ashkenazi Jewish women (whose ancestors
came from Eastern Europe) are more likely to be BRCA gene carriers.
Some experts recommend gene tests for women who are of Ashkenazi Jewish descent
if they have one or both of the following:
- Any first-degree relative with breast or ovarian cancer at age 50 or younger.
First-degree relatives are parents, sisters and brothers, and
children.
- Two second-degree relatives on the same side of the
family with breast or ovarian cancer. Second-degree relatives are aunts and
uncles, nieces and nephews, and grandparents.
- If you are not of Ashkenazi Jewish descent,
some experts recommend a gene test if you have one or more of the
following:
- Two first-degree relatives with breast cancer, one of whom
was diagnosed before age 50
- Three or more first- or second-degree
relatives with breast cancer, diagnosed at any age
- Both breast and
ovarian cancer among your first- and second-degree relatives
- A first-degree relative with cancer in
both breasts
- Two or more relatives with ovarian
cancer
- One relative with both breast and ovarian
cancer
- A male relative with breast cancer
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
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:
- Having screening tests (such as clinical breast exams, mammograms, and MRIs) more often and starting them at an earlier age.
- Taking medicines such as tamoxifen or raloxifene.
- Having a
preventive
mastectomy.
- Having their ovaries removed
(oophorectomy).
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:
- For breast cancer: A
yearly mammogram and/or an
MRI, a clinical breast exam at regular
times, preventive mastectomy (removal of both breasts), having your
ovaries removed, taking a medicine (tamoxifen), or having your
children before age 30
- For ovarian cancer:
Having your ovaries removed (oophorectomy) after
you are done having children, or after age 35
You will be asked to sign a consent form before the test.
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.
Breast Cancer Risk: Should I Have a BRCA Gene Test?
How It Is Done
The health professional drawing blood
will:
- Wrap an elastic band around your upper arm to
stop the flow of blood. This makes the veins below the band larger so it is
easier to put a needle into the vein.
- Clean the needle site with
alcohol.
- Put the needle into the vein. More than one needle stick
may be needed.
- Attach a tube to the needle to fill it with
blood.
- Remove the band from your arm when enough blood is
collected.
- Apply a gauze pad or cotton ball over the needle site as
the needle is removed.
- Apply pressure to the site and then a
bandage.
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.
Risks
There is very little chance of a problem from
having blood sample taken from a vein.
- You may get a small bruise at the site. You can
lower the chance of bruising by keeping pressure on the site for several
minutes.
- In rare cases, the vein may become swollen after the blood
sample is taken. To treat this, you can use a warm compress several times a
day.
- Ongoing bleeding can be a problem for people with bleeding
disorders. Aspirin, warfarin (Coumadin), and other blood-thinning medicines can
make bleeding more likely. If you have bleeding or clotting problems, or if you
take blood-thinning medicine, tell your doctor before your blood sample is
taken.
Some women may be
worried about the test results and how it will affect their life insurance,
disability insurance, or long-term care insurance.
Results
A breast cancer (BRCA) gene test is a
blood test to check your chance of developing
breast cancer and
ovarian cancer. Test results may take several
weeks.
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.
- If a family member has a known BRCA change,
other family members may want to be tested.
- If your family member with breast
or ovarian cancer tests negative for BRCA changes, you probably don't carry
those changes, either. In this case, you have the same chance of
cancer as that of the general public, based on your age and personal and family
history.
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.
- If you have a strong family history of breast cancer, a
negative BRCA result does not mean that you will not develop breast cancer.
BRCA1 and BRCA2 gene changes do cause a higher chance of breast cancer. But
other gene changes are possible and may cause cancer.
- If you have a
family member with breast cancer, think about asking the family member to be
tested for a gene change before you have a test. If your family member's BRCA
tests results are negative, it usually is not helpful to test the rest of the
family.
- Most
insurance companies will cover the cost of genetic testing for those who meet
the conditions for testing.
- The discovery of
a genetic disease that is not causing symptoms now (such as breast cancer) should not affect your future ability to gain employment
or health insurance coverage. A law in the United States, called the Genetic
Information Nondiscrimination Act of 2008 (GINA), protects people who have DNA
differences that may affect their health. This law does not cover life
insurance, disability insurance, or long-term care
insurance.
- The United States Preventive Services Task
Force (USPSTF) does not recommend BRCA testing for women who do not
have family risk factors.2
- For women from families that do not have risk factors
for BRCA changes, a genetic test is not likely to give any useful information
about their chance of developing breast cancer. Women from
average-risk families rarely have a positive test. A BRCA
gene test is not recommended for a person without risk factors, because the
test can give a
false-positive test result.
- Breast Cancer Risk: Should I Have a BRCA Gene Test?
- Breast Cancer: What Should I Do if I'm at High Risk?
Other Places To Get Help
Organization
|
FORCE: Facing Our Risk of Cancer Empowered |
| 16057 Tampa Palms Boulevard West |
| PMB #373 |
| Tampa, FL 33647 |
| Phone: |
1-866-288-RISK (1-866-288-7475) toll-free |
| Fax: |
(954) 827-2200 |
| Email: |
info@facingourrisk.org |
| Web Address: |
www.facingourrisk.org |
| |
|
FORCE is an organization that provides educational and emotional support for women who are making decisions about surgery to prevent breast or ovarian cancer because they are at high risk. This website also has resources for women who have cancer and are concerned about their cancer coming back. There are online resources as well as a helpline, newsletters, and information on local groups and annual conferences.
|
|
References
Citations
- National Cancer Institute (2009). BRCA1 and BRCA2: Cancer risk and genetic testing. Available online: http://www.cancer.gov/cancertopics/factsheet/Risk/BRCA.
- U.S. Preventive Services Task Force (2005). Genetic
risk assessment and BRCA mutation testing for breast and ovarian cancer
susceptibility: Recommendation statement. Annals of Internal Medicine, 143(5): 355–361.
- Fleming GF, et al. (2009). Epithelial ovarian cancer. In RR Barakat et al., eds., Principles and Practice of Gynecologic Oncology, 5th ed., pp. 763–835. Philadelphia: Lippincott Williams and Wilkins.
Credits
| By |
Healthwise Staff |
| Primary Medical Reviewer |
Sarah Marshall, MD - Family Medicine |
| Specialist Medical Reviewer |
Douglas A. Stewart, MD - Medical Oncology |
| Last Revised |
June 28, 2011 |
National Cancer Institute (2009). BRCA1 and BRCA2: Cancer risk and genetic testing. Available online: http://www.cancer.gov/cancertopics/factsheet/Risk/BRCA.
U.S. Preventive Services Task Force (2005). Genetic
risk assessment and BRCA mutation testing for breast and ovarian cancer
susceptibility: Recommendation statement. Annals of Internal Medicine, 143(5): 355–361.
Fleming GF, et al. (2009). Epithelial ovarian cancer. In RR Barakat et al., eds., Principles and Practice of Gynecologic Oncology, 5th ed., pp. 763–835. Philadelphia: Lippincott Williams and Wilkins.
