BRCA Genetic Test
Reviewed
Also called: BRCA gene test, BRCA1/BRCA2 test, Breast cancer susceptibility gene test, BRCA1 test, BRCA2 test, Breast cancer gene 1 and 2 test
A BRCA genetic test uses a sample of your blood, saliva (spit), or cells from inside of your cheek to look for changes in your BRCA1 and BRCA2 genes.
Specimen: Blood, saliva (spit), or cheek swab (buccal cells)
Why this test may be ordered
- To find out if you have harmful changes in BRCA1 or BRCA2 genes that increase your risk of breast, ovarian, prostate, or pancreatic cancer
- If you have a strong family history of certain cancers (e.g., female breast cancer before age 50, male breast cancer, ovarian cancer, pancreatic cancer, or metastatic prostate cancer)
- If you have Ashkenazi (Eastern European) Jewish ancestry, where BRCA variants are more common
- If you have had one of these cancers and want to know if a BRCA variant contributed to it
Preparation and collection
For a blood test: You don't need any special preparations. For a saliva test: A half hour before the test, you may need to stop eating, drinking, or smoking. Follow all the instructions your provider gives you or the instructions in an at-home kit. With any type of genetic test, you may want to meet with a genetic counselor first to see if testing is right for you.
A BRCA test can use either a sample of your blood, saliva, or a cheek swab. You may be able to use an at-home saliva test kit to check for the three most common harmful variations in BRCA genes. But there are more than 1000 known variations. A home test can't rule out all of them.
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. There are no risks linked to providing a saliva sample or having a cheek swab.
Understanding results
Your provider or genetic counselor will need to explain how your results affect your risk for certain cancers. That's because the meaning of your test results depends on the exact type of BRCA variant you have and your personal and family health history.
- Negative (normal): A negative (normal) result means that the test didn't find any harmful changes in your BRCA genes. Limitation: How this affects your cancer risk depends on whether you've already had cancer and whether a member of your family has a harmful BRCA variant. Next step: Your provider or genetic counselor will need to explain how your results affect your risk for certain cancers.
- Uncertain (variant of uncertain significance, VUS): It means that a variant in your BRCA genes was found, but researchers don't know whether that variant causes cancer. Limitation: That's because the meaning of your test results depends on the exact type of BRCA variant you have and your personal and family health history. Next step: After your test, a counselor can help with the medical and emotional impact that your results may have on you and your family.
- Positive (likely pathogenic variant): It means that you have a harmful gene variant that is known to increase the risk of certain cancers. Limitation: But the test cannot tell whether you will develop cancer. Not everyone who has a harmful variant in BRCA1 or BRCA2 will get cancer. Next step: If your results show that you have a harmful variant in your BRCA genes, talk with your provider about ways to lower your cancer risk.
- The test cannot tell whether you will develop cancer; it only indicates an increased risk.
- A negative result does not rule out all harmful variants, as there are over 1000 known BRCA variants and many are not tested.
- At-home test kits only check for the three most common harmful variations and cannot rule out all possible variants.
- An uncertain result (VUS) may be reclassified in the future as more research is done.
- Results must be interpreted along with personal and family health history.
What to do next
After your test, a counselor can help with the medical and emotional impact that your results may have on you and your family.
- What does my result mean for my personal cancer risk?
- Should I share these results with my family members?
- What are my options for reducing my cancer risk?
- How often should I have cancer screenings?
- Can the classification of an uncertain result change later?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.