The BRCA gene test identifies changes within the BRCA1 and BRCA2 genes. The test analyzes a person’s blood or saliva sample to determine if they carry genetic alterations that increase their likelihood of developing certain cancers. This information guides healthcare decisions and preventive strategies.
Understanding BRCA Genes
Everyone has two copies of the BRCA1 and BRCA2 genes, one from each parent. These genes function as tumor suppressors, producing proteins that are instrumental in repairing damaged DNA within cells. This repair mechanism helps prevent uncontrolled cell growth and tumor formation.
If a harmful mutation occurs in one of these BRCA genes, their ability to repair DNA can be compromised. This impaired function means DNA damage may not be corrected effectively, which can lead to an increased risk of cells developing into cancer. Many harmful mutations have been identified.
Purpose of the BRCA Gene Test
The BRCA gene test detects inherited mutations in BRCA1 and BRCA2, which are associated with an elevated lifetime risk of certain cancers. For women, this includes an increased risk of breast and ovarian cancers. Women with harmful BRCA1 or BRCA2 mutations have a breast cancer risk about five times higher and an ovarian cancer risk ten to thirty times higher than the general population.
BRCA mutations can also increase the risk for other cancer types, including prostate and pancreatic cancer (particularly with BRCA2 mutations), male breast cancer, and melanoma.
Who Should Consider Testing
BRCA gene testing is considered for individuals with specific risk factors. A personal or family history of certain cancers, especially at younger ages, is a key factor. This includes female breast cancer diagnosed before age 50, triple-negative breast cancer before age 60, or male breast cancer at any age.
Individuals with a family history of ovarian, fallopian tube, or primary peritoneal cancer also qualify. If a close relative has a known BRCA mutation, testing may be recommended due to the 50% chance of inheriting the mutation. Ethnicity also plays a role, as individuals of Ashkenazi Jewish descent have a higher prevalence of specific BRCA mutations. A genetic counselor can help assess personal and family history to determine if testing is appropriate.
The Testing Process
A BRCA gene test begins with a consultation with a genetic counselor or another healthcare professional specializing in genetics. This meeting discusses the benefits, limitations, and implications of testing. The counselor also gathers a detailed personal and family medical history to guide the testing decision.
The test involves a blood sample, drawn like a standard blood test. In some cases, a saliva sample or cells from inside the cheek may be collected. Since inherited mutations are present in every cell, these samples are sufficient for analysis. The collected sample is sent to a specialized laboratory for DNA analysis, and results can take several weeks.
Understanding Your Results
Genetic test results for BRCA genes fall into three categories: positive, negative, or a variant of uncertain significance (VUS). A positive result indicates that a harmful mutation in BRCA1 or BRCA2 has been detected. This means an increased risk for certain cancers, though it does not guarantee that cancer will develop. For example, women with a BRCA1 or BRCA2 mutation have a 45% to 85% likelihood of developing breast cancer and a 10% to 46% chance of ovarian cancer in their lifetime.
A negative result means no known harmful BRCA mutations were found, suggesting a risk similar to the general population. However, a negative result does not eliminate all cancer risk, as other genetic factors or lifestyle choices can still influence cancer development. A variant of uncertain significance (VUS) indicates that a change in the gene was found, but there is not enough data to determine if it is harmful or benign. Most VUS results are eventually reclassified as benign, and cancer risk management should be based on family history and other risk factors until reclassification occurs.
Next Steps After Testing
Upon receiving BRCA test results, a follow-up consultation with a genetic counselor is recommended to understand the implications for personal health and family members. For individuals with a positive result, several options are available to manage the increased cancer risk. These may include enhanced cancer surveillance, such as more frequent mammograms and breast MRIs starting at a younger age.
Preventive measures can also be considered, such as risk-reducing surgeries like prophylactic mastectomy or removal of the ovaries and fallopian tubes (salpingo-oophorectomy). Medications, known as chemoprevention, may also be an option to reduce cancer risk. For those with negative results, continued standard cancer screenings based on general population guidelines and personal history are recommended. Regardless of the result, ongoing consultation with healthcare professionals ensures personalized guidance and appropriate risk management strategies.