What is a BRCA test?
A BRCA test looks for changes, known as mutations, in genes called BRCA1 and BRCA2. Genes are parts of DNA passed down from your mother and father. They carry information that determines your unique traits, such as height and eye colour. Genes are also responsible for certain health conditions. BRCA1 and BRCA2 are genes that protect cells by making proteins that help prevent tumours from forming.
A mutation in a BRCA1 or BRCA2 gene can cause cell damage that may lead to cancer. Women with a mutated BRCA gene have a higher risk of getting breast or ovarian cancer. Men with a mutated BRCA gene are at a higher risk for getting breast or prostate cancer. Not everyone who inherits a BRCA1 or BRCA2 mutation will get cancer. Other factors, including your lifestyle and environment, can affect your cancer risk. If you find out you have a BRCA mutation, you may be able to take steps to protect your health. Other names for this test are BRCA gene test, BRCA gene 1, BRCA gene 2, breast cancer susceptibility gene1, and breast cancer susceptibility gene 2.
What is it used for?
This test is used to find out if you have BRCA1 or BRCA2 gene mutation. A BRCA gene mutation can increase your risk of getting cancer.
Why do you need a BRCA test?
BRCA testing is not recommended for most people. BRCA gene mutations are rare, affecting only about 0.2 percent of the population. But you may want this test if you think you are at a higher risk of having the mutation. You are more likely to have a BRCA mutation if you:
Have or had breast cancer that was diagnosed before age 50
Have or had breast cancer in both breasts
Have or had both breast and ovarian cancer
Have one or more family members with breast cancer
Have a male relative with breast cancer
Have a relative already diagnosed with a BRCA mutation
Are of Ashkenazi (Eastern European) Jewish ancestry: BRCA mutations are much more common among this group compared to the general population. BRCA mutations are also more common in people from other parts of Europe, including, Iceland, Norway, and Denmark.
What happens during a BRCA test?
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
Will you need to do anything to prepare for the test?
You don't need any special preparations for BRCA testing. But you may want to meet with a genetic counsellor first to see if the test is right for you. Your counsellor may talk with you about the risks and benefits of genetic testing and what different results can mean. You should also think about getting genetic counselling after your test. Your counsellor can discuss how your results may impact you and your family, both medically and emotionally.
Are there any risks to the test?
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
What do the results mean?
Most results are described as negative, uncertain, or positive, and typically mean the following:
A negative result means no BRCA gene mutation was found, but it doesn't mean you won't ever get cancer.
An uncertain result means some kind of BRCA gene mutation was found, but it may or may not be linked with an increased cancer risk. You may need more tests and/or monitoring if your results were uncertain.
A positive result means a mutation in BRCA1 or BRCA2 was found. These mutations put you at a higher risk of getting cancer. But not everyone with the mutation gets cancer.
It may take several weeks to get your results. If you have questions about your results, talk to your health care provider and/or your genetic counsellor.
Is there anything else I need to know about a BRCA test?
If your results show you have a BRCA gene mutation, you can take steps that may lower your risk of breast cancer. These include:
More frequent cancer screening tests, such as mammograms and ultrasounds. Cancer is easier to treat when it's found in the early stages.
Taking birth control pills for a limited time: Taking birth control pills for a maximum of five years has been shown to reduce the risk of ovarian cancer in some women with BRCA gene mutations. Taking the pills for more than five years to reduce cancer is not recommended. If you were taking birth control pills before you took the BRCA test, tell your health care provider how old you were when you started taking the pills and for how long. He or she will then recommend whether or not you should continue taking them.
Taking cancer-fighting medicines: Certain drugs, such as one called tamoxifen, have been shown to reduce the risk in women with a higher risk of breast cancer.
Having surgery, known as a preventive mastectomy, to remove healthy breast tissue: Preventive mastectomy has been shown to reduce breast cancer risk by as much as 90 percent in women with a BRCA gene mutation. But this is a major operation, only recommended for women at very high risk for getting cancer.