Genetic Risk for Breast Cancer

Are you curious about how your genes might influence your breast cancer risk? You’re not alone. Understanding genetic risk can empower you to take control of your health.

What Does Genetic Risk for Breast Cancer Mean?

Genetic risk refers to the likelihood of developing breast cancer because of changes (mutations) in certain genes. These are changes that you are born with and can be inherited from one of your parents. These gene mutations don’t mean you’ll get breast cancer, but they can raise your risk significantly compared to the general population.

The Most Important Breast Cancer Genes: BRCA1 & BRCA2

Genetic or hereditary factors are linked to bout 5% to 10% of all breast cancer cases. The two most well-known genes linked to breast cancer are BRCA1 and BRCA2. They account for at least 60% of hereditary breast cancer. When functioning normally, these genes help repair damaged DNA. If a mutation occurs, their ability to fix DNA is weakened, allowing cancer cells to grow unchecked, leading to breast and ovarian cancers.

• BRCA1: Women with a BRCA1 mutation have an estimated 60% to 72% lifetime risk of developing breast cancer by age 70.
• BRCA2: Women with a BRCA2 mutation have about a 55% to 69% risk of developing breast cancer by age 70.

Mutations in these genes also increase your risk for other cancers, such as pancreatic cancer and possibly melanoma. Men also have increased risks for prostate cancer and male breast cancer.

Other Genes That Affect Risk for Breast Cancer

While BRCA1 and BRCA2 get most of the attention, the following gene mutations are less common but may raise your risk for breast cancer as well:

• ATM
• CDH1
• CHEK2
• PALB2
• PTEN
• TP53
• STK11
• RAD51C
• RAD51D

Who Should Consider Genetic Testing for Breast Cancer?

There can be many different reasons to have genetic testing to check for hereditary breast cancer risks. Some common red flags for testing are:

• Have a close relative diagnosed with breast or ovarian cancer, especially before age 50.
• Have several family members on the same side (maternal or paternal) with breast or prostate cancer.
• Have a close relative with ovarian, pancreatic, or male breast cancer.
• Have a close relative who has had breast cancer in both breasts.
• Are of Ashkenazi Jewish descent (mutation rates are somewhat higher).

If you are concerned about your risk, talk to your doctor or a genetic counselor to help you weigh the benefits and decide if testing is right for you. If you are tested, the genetic counselor will explain the results to you and possibly other family members

Understanding Your Genetic Test Results 

Genetic testing can be done on samples of blood or saliva. The samples are sent to a lab for testing, and the results usually take 2-3 weeks to get back. Depending on who ordered the test, your doctor or genetic counselor will receive the results to discuss them with you in detail so you can understand what they mean and what to do next.

The results of the genetic test will come back as:

• Positive: Your test shows you have a gene mutation in one of the genes it tested for, which may put you at a higher risk for developing breast cancer. However, this doesn’t mean you will get cancer.
• Negative: Your test didn’t detect a mutation in the genes it tested for. This doesn’t mean you will never get breast cancer. Depending on your risk factors, you may still be considered at high risk of cancer with a negative result.
• Variant of uncertain significance (VUS): The test shows a change in one of the genes, which is not yet known if it is damaging or not. This is treated as a negative result. The lab may reclassify it in the future as positive or negative. Most of these will get reclassified to negative.

It’s important to remember that the results of your genetic test do not tell you if you have cancer or if you will ever get cancer in the future.

What Should I Do After Getting Positive Results?

If you test positive, your healthcare team will help you develop a proactive plan for monitoring and reducing your personal risk.

• Personalized screening: Your doctor may recommend you get earlier or more frequent mammograms or MRIs.
• Preventive options: Your doctor may recommend early detection tests, preventive (prophylactic) surgery, medication to reduce cancer risks (chemoprevention), or lifestyle changes to lower risk.
• Family impact: Sharing your results with your family is important because your children, siblings, and other relatives will have increased risks of also carrying the same mutation.

Key Takeaways

• Most breast cancer cases aren’t directly tied to hereditary mutations, but understanding your family history and genetic makeup can make a big difference in your health journey.
• Genetic testing is not for everyone, but it is especially valuable for those with strong family histories or certain ethnic backgrounds.
• Knowing your genetic risk empowers you to make informed choices—whether that means screening more often, changing lifestyle habits, or discussing options with a care team.

Being proactive about genetic risk means putting knowledge and power back in your hands. If you have questions about your personal or family history, ask your doctor or reach out to a genetic counselor. Your genetic story is just one chapter in your breast health journey, and understanding it is a smart step forward.

At Memorial Healthcare System, we believe early detection saves lives and prevention is just as important as treatment. That’s why we provide a full spectrum of breast health services to support women at every stage of care. From screening and diagnostic mammograms to high-risk monitoring and genetic testing and counseling, as well as breast cancer treatment and survivorship programs, Memorial offers care that is both compassionate and comprehensive.

Our nationally accredited Women’s Imaging Centers and Breast Cancer Center bring together expert radiologists, oncologists, surgeons, and nurse navigators who guide you every step of the way. Whether you need a routine screening, follow-up imaging, or specialized treatment, we are here to give you peace of mind and the best possible outcomes.