The BRCA blood test is a genetic test that is used to check for specific mutations that occur in the BRCA1 and BRCA2 genes. The gene normally helps to control cell growth. If there are abnormalities with one or both of these genes, then it can place someone at a greater risk of breast cancer development. Ovarian cancer risks can also be measured through this specific blood test.
The BRCA blood test does not actually screen for any cancer. It is used instead as a tool for those who have a family history of breast or ovarian cancer so they can determine their future risks of cancer development. This test is often ordered by a genetic counselor, but other medical providers may also choose to order it if there is patient concern.
When To Ask About the BRCA Blood Test
If women are determined to have BRCA1 or BRCA2 gene changes, then they are at a higher risk of developing ovarian or breast cancer. Men can also have gene changes that place them at an increased risk of developing breast cancer. These gene changes can also place both genders at a higher risk for other cancers as well.
These genetic changes can be inherited from either the father or the mother. Certain attributes may make it more likely that an individual has a BRCA gene change. If a patient is diagnosed with breast cancer before the age of 50, then there is a good chance that the BRCA blood test would provide a positive result.
Having one or more men in the family with a diagnosis of breast cancer also increases the risk of a BRCA gene change. Having breast cancer in both breasts or having breast and ovarian cancer also indicate gene changes. People from certain ancestral backgrounds, especially Ashkenazi Jewish populations, have a very high diagnosis rate for BRCA gene changes.
What If a Patient Doesn’t Meet These Criteria?
Men or women who don’t meet these criteria are not likely to have any BRCA changes and test negative on the blood test. About 0.03% of women in the world today are believed to have a BRCA gene change and it is so uncommon in men that statistics are not even kept.
This doesn’t mean that other screening tests for cancer should be ignored. The BRCA blood test will not detect cancer if it is present. This means additional measures must be taken. Screening tests, such as a mammogram or an MRI, should be completed on a regular basis. Certain medications may be offered to those who may be at a high risk of cancer development, such as raloxifene or tamoxifen.
For women who do have the BRCA test come back as positive, a radical preventative measure is to have a preventative mastectomy and oophorectomy. This removes the breast tissues and ovaries that are at the highest risk of developing a cancer with this gene change.
What Do the Test Results Mean?
The test results from the BRCA blood test may take several weeks to come back because it is examining genetic structures. If the test is reported as normal, then this means that there were no changed found in the BRCA1 or BRCA2 genes. Family risks must also be considered with this test result so that personal risks can be better evaluated. In general, however, this means that an individual has the same risks of cancer development as the general public.
Even when the test results are positive or abnormal, only 5-10% of cancers that are presently discovered can be linked to the gene changes. Having a direct family history of breast or ovarian cancers can increase these odds, but this is true even if there aren’t BRCA gene changes. Women who do have confirmed gene changes do have up to an 84% chance of developing breast cancer at some point in their lives.
There is also up to a 40% chance of developing ovarian cancer at some point during the lifetime. Although these percentages seem high, the risks can also be as low as 35% and 20% respectively, so the factor of risk is a very wide range.
Men who have a positive result also have an increased risk of prostate and pancreatic cancer in addition to breast cancer.
A final result, known as VUS [variant of uncertain significance], shows that there are gene changes that may have happened, but the result of that change may or may not be medically significant. This result may require ongoing testing to determine ongoing risk factors for cancer development.
The BRCA blood test doesn’t screen for cancer, but it does screen for cancer risks. It will not be ordered if you do not meet the qualifying factors. If you have any specific questions about this blood test and whether it should be ordered for you, then schedule an appointment with your medical provider to discuss the information in this guide.