Many women with breast cancer or a family history of breast cancers consider genetic testing to learn if they carry inherited mutations like BRCA1/2 that raise cancer risk. Current guidelines emphasize discussing testing with your doctor or genetic counselor. For example, ASCO/SSO guidelines recommend offering BRCA1/2 testing to all women diagnosed with breast cancer by age 65, and selected older women based on personal/family history or ancestry (Bedrosian et al., 2024). Similarly, public health experts advise testing for those with strong family histories of breast, ovarian, pancreatic or prostate cancer, especially if cancers occur at young ages or involve multiple relatives (CDC, 2024). Women of Ashkenazi Jewish descent or those with known relatives who carry a BRCA mutation should also discuss testing (Mayo clinic, 2023). In short, testing is usually considered when your personal or family history suggests a hereditary risk for breast cancer.
BRCA 1 mutation on Chromosome 17 and BRCA 2 mutation on Chromosome 13 shown in red (NIH, 2017)
Who should consider genetic testing?
Medical guidelines highlight several groups who may benefit from testing. Generally, this includes women with:
- A history of breast cancer, especially if diagnosed young (≤50) or with aggressive subtypes such as triple-negative (Bedrosian et al., 2024).
- Breast cancer plus other cancers: breast cancer and other primary (e.g., ovarian, pancreatic, prostate) or a secondary breast cancer.
- Family history: multiple relatives (parents, siblings, children, or close kin) with breast, ovarian, pancreatic, or high-grade prostate cancer, particularly at young ages (Mayo clinic, 2023).
- Known family mutation: a known BRCA1/2 (or other high-risk gene) mutation in a relative.
- Ethnic risk factors: Ashkenazi Jewish ancestry (higher chance of certain founder mutations) combined with any relevant personal or family history (CDC, 2024).
In practice, most doctors use risk assessment tools or questionnaires to decide who should be offered testing. For women with breast cancer, ASCO/SSO explicitly recommends BRCA testing for all patients ≤65 years old, and for older patients who have risk factors or are candidates for therapies that depend on genetic status (Bedrosian et al., 2024).
Understanding Genetic Test Results
Genetic test results generally fall into three categories: positive (pathogenic), negative, or variant of uncertain significance (VUS). Understanding each is key to what happens next:
- Positive (pathogenic variant): This means the test found a mutation known to raise cancer risk. For example, women with a pathogenic BRCA1/2 mutation have a very high lifetime breast cancer risk of ~69-72%, versus about 13% for average-risk women (Hesse-Biber et al., 2023). A positive result means you have inherited a high-risk gene change. In this case, you and your healthcare team will consider more aggressive risk-management steps. It also means your close relatives each have a 50% chance of carrying the same mutation. Family members can then get targeted testing for that specific mutation.
- Negative: A negative result means no harmful mutation was found in the genes tested. This generally indicates you don't carry a high-risk BRCA1/2 (or other tested gene) mutation. However, a negative result does not guarantee you have average risk if your family history is strong. It may simply mean that the known genes that were tested don't explain your family's cancers, or there could be another undiscovered mutation. In fact, Mayo Clinic notes that a negative result "may mean you don't have the gene change," but it could also mean you might have a change "that hasn't been discovered yet" (Mayo clinic, 2023).
- Variant of Uncertain Significance (VUS): A genetic change was found, but its impact on cancer risk is unclear. VUS is not an actionable finding which should be treated as inconclusive and not change your medical management (ASBrS Board of Directors, 2018). Over time, research accumulation may reclassify a VUS as harmful or benign.
Making the Decision: Support and Shared Choices
Deciding whether to undergo genetic testing is a personal, shared decision between you and your care team. A genetic counselor or doctor can help weigh the pros and cons of testing your situation (ASBrS Board of Directors, 2018). They will explain in clear terms what a positive or negative result could mean for your life and your family. This includes discussing emotional aspects too where some people feel relief at knowing their risk, while others may feel anxiety or uncertainty. In fact, studies note that learning a positive BRCA result can trigger strong emotions like shock, anxiety or guilt (Hesse-Biber et al., 2023). These feelings are natural. Pre-test counseling is designed to prepare you for such outcomes, and post-test counseling helps you process the result.
Conclusion
Genetic testing for breast cancer risk has the potential to save lives by informing personalized prevention and treatment plans. The decision to test is guided by evidence-based criteria and your individual situation. If you're wondering "Should I get tested?", start by discussing your personal and family history with a healthcare provider. A genetics professional can walk you through the process, risks, and benefits in everyday language. Remember, testing is just a tool. What matters most is what you and your doctor do with the information. Whether you proceed or not, you'll have helped make an informed choice that's right for your health and for your family.
References
ASBrS Board of Directors. (2018). Genetic testing for hereditary breast cancer. https://www.breastsurgeons.org/docs/statements/asbrs-ccs-genetic- testing.pdf
Bedrosian, I., Somerfield, M. R., Achatz, M. I., Boughey, J. C., Curigliano, G., Friedman, S., Kohlmann, W. K., Kurian, A. W., Laronga, C., Lynce, F., Norquist, B. S., Plichta, J. K., Rodriguez, P., Shah, P. D., Tischkowitz, M., Wood, M., Yadav, S., Yao, K., & Robson, M. E. (2024). Germline testing in patients with breast cancer: ASCO-Society of Surgical Oncology Guideline. Journal of Clinical Oncology, 42(5), 584-604. https://doi.org/10.1200/jco.23.02225
BRCA gene test for breast and ovarian cancer risk - Mayo Clinic. (2023, October 21). https://www.mayoclinic.org/tests-procedures/brca-gene-test/about/pac- 20384815
Cancer risk for women carrying BRCA mutations. (2017, July 12). Cancer.gov. https://www.cancer.gov/news-events/cancer-currents-blog/2017/brca- mutation-cancer-risk
Genetic testing for hereditary breast and ovarian cancer. (2024, August 27). Hereditary Breast and Ovarian Cancer. https://www.cdc.gov/breast-ovarian- cancer-hereditary/testing/
Hesse-Biber, S., Seven, M., Shea, H., Heaney, M., & Dwyer, A. A. (2023). Racial and Ethnic Disparities in Genomic Healthcare Utilization, Patient Activation, and Intrafamilial Communication of Risk among Females Tested for BRCA Variants: A Mixed Methods Study. Genes, 14(7), 1450. https://doi.org/10.3390/genes14071450