Hereditary Breast Cancer

All cancers come from genetic mutations. Usually, these happen in specific cells during a person’s life. In some cases, however, people inherit mutations that can influence cancer. This occurs more frequently for specific types of the disease, including cancer. When these mutations help cause breast cancer, doctors call it hereditary breast cancer.

Researchers have identified two main mutations that play a role in breast (and ovarian) cancer: BRCA1 and BRCA2 (for breast cancer 1 and breast cancer 2).

Genes, Risk—and Understanding

It can be easy to misinterpret what it means to have these inherited mutations. First, understand that it is believed that everyone has these genes. The mutation of a gene causes the problem. The mutations don’t mean a person will definitely get breast or ovarian cancer. Instead, they greatly increase a person’s risk for these diseases. At the same time, most women get breast cancer without inheriting BRCA mutations. In other words, these genes are not the last word. For more information about genetics and risks, please see our High Risk page.

Your Status and Your Future: Testing

If you decide you want to know more about your risks, family history and genetic testing can help give you some answers:

Family History: Having family members with breast cancer doesn’t necessarily mean you have a BRCA mutation—but it can increase your chances. A genetic counselor can help you look for important signs in your family history: If you or a relative had breast cancer before age 45, cancer in both breasts or male breast cancer, it might indicate hereditary breast cancer, also putting you at risk. Several cases of breast or ovarian cancer on the same side of a family can also indicate this. Other cancers in your family history can also point to a personal risk.

Genetic Testing: More precise information can come from blood tests for the BRCA mutations. Many women find these tests empowering—finding out your genetic status can open the door to medical options and some research studies. On the other hand, finding out your risk can sometimes feel overwhelming—both to you and your loved ones. This personal choice should an informed one.

Decision: Speak to a genetic counselor to help you decide what’s best for you. Whatever option you choose, take your time with this very personal decision. Remember that the tests are not definitive since currently they only detect two genes involved. (Other mutations associated with hereditary breast cancer occur very rarely and doctors do not yet test for them.) With the constantly advancing knowledge in this field, be sure you get up-to-date information. And remember—there is no right or wrong answer, just the one you decide is best for you.

Taking Care of Yourself

Results from genetic testing can help you make more-informed decisions about your health, whether you are at high risk or already have breast cancer:

If you are at high risk for hereditary breast cancer, you have options for protecting yourself. Take your time and gather accurate information about these very personal decisions. Options include:

  • Medicine or chemoprevention
  • Preventive, or prophylactic surgery to remove breasts and/or ovaries
  • Surveillance with MRI or ultrasound to detect breast cancer early

If you already have breast cancer, and tests show a hereditary mutation, this information can still inform and improve your healthcare decisions and treatment. Your test results can also help your family members understand their risk.

More Information