BRCA gene test for breast cancer
BRCA gene test for breast cancer
The BRCA gene test is a blood test that uses DNA analysis to identify harmful changes (mutations) in either one of the two breast cancer susceptibility genes — BRCA1 and BRCA2. Women who have inherited mutations in these genes face a much higher risk of developing breast cancer and ovarian cancer compared with the general population. The BRCA gene test is offered only to people who are likely to have an inherited mutation, based on personal or family history, or who have specific types of breast cancer. The BRCA gene test isn't routinely performed on women at average risk of breast and ovarian cancers.
Having a BRCA gene mutation is uncommon. Inherited BRCA gene mutations are responsible for about 5 percent of breast cancers and about 10 to 15 percent of ovarian cancers.
After having a BRCA gene test performed, you learn whether you carry an inherited BRCA gene mutation and receive an estimate of your personal risk of breast cancer and ovarian cancer. Genetic counseling is an important part of the BRCA gene test process.
Why it's done
Mutations to either breast cancer gene — BRCA1 or BRCA2 — significantly increase your risk of breast cancer and ovarian cancer when compared with the cancer risk of a woman without a BRCA gene mutation. Men with inherited BRCA gene mutations also face an increased risk of breast cancer. BRCA mutations may increase the risk of other types of cancer in women and men as well.
You might be at increased risk of having a BRCA gene mutation — and a candidate for BRCA gene testing — if you have:
Who should consider BRCA gene testing?
There's really no medical risk associated with being tested for a BRCA gene mutation. Rather, risks are tied to the emotional, financial, medical and social implications of your test results.
If you test positive for a BRCA gene mutation, you may face:
On the other hand, if you test negative for a BRCA mutation or your results aren't clear-cut, you may experience:
How you prepare
The first step in the BRCA gene testing process is to meet with a genetic counselor. As soon as you consider having any genetic test, meet with a genetic counselor to determine whether it's appropriate for you and to discuss the potential risks, limitations and benefits.
The genetic counselor takes a detailed family and medical history, assesses your risk of developing cancer, discusses risks and benefits of genetic testing, and outlines your options.
To prepare for your meeting with a genetic counselor:
Whether or not to proceed with genetic testing after you meet with a genetic counselor is up to you.
If you decide to have a BRCA gene test done, prepare yourself for the emotional and social implications that learning your genetic status might have. Test results could also fail to provide you with clear-cut answers regarding your cancer risk, so you should be ready to face that possibility, too.
What you can expect
The BRCA gene test is a blood test. A doctor, nurse or medical technician inserts a needle into a vein, usually in your arm, to draw the blood sample needed for testing. Your blood sample then goes to a laboratory for DNA analysis. It takes several weeks before test results are available. You meet with your genetic counselor again to learn your test results, discuss their implications and go over your options. Federal and state laws help ensure the privacy of your genetic information and protect against discrimination in health insurance and employment.
Your test results may be positive, negative or uncertain.
Positive test result
Follow-up care after a positive test result might include taking specific measures to reduce your cancer risk. What you choose to do depends on many factors - including your age, medical history, prior treatments, past surgeries and personal preferences.
To reduce your cancer risk after a positive test result, you might:
Preventive surgery doesn't eliminate all cancer risk. It's possible that cancer still might develop in any tissue that couldn't be removed through surgery.
Negative or uncertain test result
Although the BRCA gene test can detect the majority of mutations in the BRCA1 and BRCA2 genes, it's possible that you could have a gene mutation that the test wasn't able to detect. Or you may be at high risk of hereditary cancer if your family carries a high-risk gene mutation that researchers haven't yet identified and developed a test for.
Last Updated: 2010-12-28
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