BRCA Genetic Test

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 blood test: no special preparation. For saliva test: stop eating, drinking, or smoking for 30 minutes before providing the sample. For cheek swab: you may be asked to rinse your mouth before the sample is taken. Consider meeting with a genetic counselor before testing to understand the pros and cons.

A health care professional collects a blood sample from a vein in your arm for a blood test. For a saliva test, you spit into a container or use a cotton pad. For a cheek swab, a swab is rubbed against the inside of your cheek. At-home saliva test kits are available for some common variants.

For blood draw: slight pain or bruising at the needle site, which usually resolves quickly. There are no known risks linked to providing a saliva sample or having a cheek swab, as stated by MedlinePlus. Additionally, consider the emotional impact of learning genetic risk information.

Understanding results

Your test results will show whether a harmful variant was found in your BRCA genes. The results are typically reported as negative, uncertain (variant of uncertain significance, VUS), or positive (likely pathogenic). The meaning of your results depends on your personal and family health history. Always review your results with a healthcare provider or genetic counselor.

• Negative (no harmful variant found): The test did not find any harmful changes in your BRCA genes. Your cancer risk depends on whether a family member has a known harmful BRCA variant and your personal history. Limitation: A negative result does not rule out all possible harmful BRCA variants, and there are other genetic and non-genetic risk factors for cancer. Next step: Continue regular cancer screenings as recommended by your provider. Discuss further genetic counseling if you have a strong family history of cancer.
• Uncertain (variant of uncertain significance, VUS): A variant was found in your BRCA genes, but it is not yet known whether it increases cancer risk. Limitation: The classification of this variant may change as more research becomes available. It does not currently confirm an increased risk or provide clear guidance. Next step: Your provider or genetic counselor may recommend re-evaluation in the future as more information becomes available. No immediate changes to cancer screening are typically needed based on this result alone.
• Positive (likely pathogenic variant): You have a harmful gene variant known to increase the risk of certain cancers. However, having this variant does not mean you will definitely develop cancer. Limitation: This test cannot predict if or when you will get cancer; it only indicates an increased risk. The risk level varies based on personal and family history. Next step: Talk with your provider about enhanced cancer screening, risk-reducing medications, or preventive surgery. Consider sharing results with family members who may also be at 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

Share your results with a healthcare provider or genetic counselor to understand what they mean for you and your family. Based on results, discuss personalized cancer screening, risk-reducing strategies (medications or surgery), and consider informing at-risk family members.

• 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

U.S. National Library of Medicine: BRCA Genetic Test