The human body contains two important genes, BRCA1 and BRCA2, which play a significant role in maintaining cellular health. These genes produce proteins that help repair damaged DNA, preventing uncontrolled cell growth. This repair function helps keep cells healthy. When these genes work as intended, they act as tumor suppressors, helping to protect the body from developing certain cancers.
However, sometimes changes, known as mutations, can occur within the BRCA1 or BRCA2 genes. These mutations can disrupt the genes’ ability to produce functional repair proteins. When this DNA repair mechanism is compromised, cells are more likely to develop additional genetic errors, which can accumulate over time. These accumulated errors increase the likelihood that a cell will become cancerous.
Purpose of BRCA Testing
BRCA testing identifies inherited mutations in the BRCA1 and BRCA2 genes. Identifying these changes helps determine an individual’s increased lifetime risk for developing certain cancers. The presence of such a mutation does not mean cancer is guaranteed, but it does indicate a higher predisposition. This information allows for proactive, personalized risk management.
These inherited mutations are associated with an elevated risk of breast cancer, particularly at younger ages, and ovarian cancer. Individuals with BRCA1 mutations face a higher lifetime risk of ovarian cancer, often ranging from 39% to 63%, while BRCA2 mutations carry a risk between 16.5% and 27%. Beyond these, BRCA mutations also increase the risk for other cancers, including prostate cancer, pancreatic cancer, and melanoma. Knowing one’s genetic status empowers individuals and healthcare providers to implement tailored screening and prevention plans.
Who Should Consider Testing
Genetic testing for BRCA1 and BRCA2 mutations is recommended for individuals with specific personal or family histories that suggest an increased genetic risk. These include:
A strong family history of breast cancer (especially before age 50) or multiple family members affected by breast or ovarian cancer across generations.
A personal diagnosis of breast cancer before age 50, triple-negative breast cancer at any age, or ovarian cancer at any age.
A personal or family history of male breast cancer or pancreatic cancer.
Ashkenazi Jewish descent, due to a higher prevalence of specific BRCA mutations.
Given the complexities of family medical histories and genetic risk assessment, consulting with a genetic counselor is an important first step to evaluate individual circumstances and determine the appropriateness of testing.
The Testing Procedure
Undergoing BRCA testing begins with a consultation with a genetic counselor. During this session, the genetic counselor explains the testing process, discusses the implications of results, and helps the individual understand their personal and family cancer risks. This discussion also includes obtaining informed consent, ensuring the individual understands the benefits, limitations, and psychological impact of genetic testing. The counselor ensures all questions are answered before proceeding.
Following the consultation, a sample is collected for laboratory analysis. This usually involves a blood draw or a saliva sample, which contain DNA for testing. The sample is sent to a laboratory where technicians analyze the DNA for BRCA1 and BRCA2 mutations. Results are available within a few weeks, though the timeframe varies by laboratory and test type.
Understanding Test Results
After undergoing BRCA testing, individuals will receive one of three types of results, each carrying distinct implications for their health management. A “positive” result indicates that a pathogenic, or disease-causing, mutation in either BRCA1 or BRCA2 was found. This means the individual has an increased lifetime risk of developing certain cancers, such as breast and ovarian cancer. However, it is important to understand that a positive result does not guarantee cancer development; it signifies a higher predisposition.
Conversely, a “negative” result means no pathogenic mutation was identified in the BRCA1 or BRCA2 genes. While this is reassuring, it does not eliminate all cancer risk. Individuals with a negative result still have the general population’s cancer risk, and other genetic or environmental factors might still contribute to cancer development. This result means their cancer risk is not elevated due to these inherited mutations.
The third possible outcome is a “variant of uncertain significance” (VUS). A VUS indicates that a genetic change was found, but its impact on cancer risk is unclear. Research is ongoing to determine if this variant is harmless or disease-causing. VUS results often require reclassification over time and are generally not used for immediate medical decisions.
Managing Your Health After Testing
Receiving BRCA test results, especially a positive one, prompts a personalized approach to health management. For individuals with a pathogenic BRCA mutation, increased cancer surveillance is a recommendation. This often includes earlier, more frequent screening, such as annual mammograms and breast MRI for breast cancer detection, starting at a younger age than general guidelines. For ovarian cancer, transvaginal ultrasounds and blood tests for CA-125 may be recommended, though their effectiveness as screening tools is debated.
Risk-reducing surgeries are another option for those with BRCA mutations. Prophylactic bilateral mastectomy, removing both breasts, can reduce breast cancer risk by approximately 90% to 95%. Similarly, prophylactic salpingo-oophorectomy, removing fallopian tubes and ovaries, can reduce ovarian cancer risk by 80% to 90% and also lower breast cancer risk. These are major decisions, and individuals consider them in consultation with their healthcare team.
Chemoprevention, using medications like tamoxifen or raloxifene, can be considered to reduce breast cancer risk in some individuals with BRCA mutations. Lifestyle modifications, such as maintaining a healthy weight, regular exercise, and a balanced diet, contribute to overall health and may influence cancer risk. Ongoing genetic counseling and consultations with a multidisciplinary healthcare team (oncologists, surgeons, gynecologists) are important for developing and adjusting a personalized care plan. The implications of test results for family members, who may also carry the mutation, are also discussed, allowing them to consider testing and risk management.