Genetic Testing for Breast Cancer Risk

Researchers continuously study gene mutations to discover more about connections to hereditary breast cancer

Woman consulting with two doctors about genetic testing for breast cancer risk.

by Kathleen Carder, Genetic Program Coordinator

If you or a close relative has breast cancer, you may wonder if genetic risk is the reason. It’s an understandable concern. You may be most familiar with BRCA1 and BRCA2 (Breast Cancer genes 1 and 2). Actress Angelina Jolie made these genes news a few years ago when she discovered she carried the BRCA1 gene.

An estimated 5 to 10 percent of breast cancers begin due to gene defects (called mutations) that we know about. Of course, that also means that the majority of breast cancers have not been from a single gene mistake passing through the family.

Facts about breast cancer genes

Researchers are continuously studying gene mutations to find those with connections to hereditary breast cancer.

Women who inherit a cancer gene mutation from a parent have an increased risk of developing cancers of the breasts and ovaries. Here’s an overview of how much your breast cancer risk increases:

  • Woman with no gene mutation: About a 12 percent chance of breast cancer before age 70
  • Woman with BRCA1: Between 55 to 80 percent chance before age 70
  • Woman with BRCA2: 51 percent chance before age 70

While these numbers may seem scary, it’s important to note that many women who inherit mutated genes never develop cancer.

Should you get genetic testing for breast cancer?

Genetic testing can help determine whether you carry an inherited gene mutation linked to breast cancer. However, only certain women meet the criteria for genetic testing. These include women who have:

  • A relative with a known breast cancer gene mutation like BRCA1 or BRCA2
  • A personal diagnosis of breast cancer before age 45
  • A family member, such as a grandparent, parent, sibling, aunt or child, diagnosed with breast cancer before age 50
  • A family member diagnosed with ovarian cancer at any age
  • An Ashkenazi Jewish heritage along with a personal or family history of breast or ovarian cancer

While it can be worrisome to contemplate that you may have a genetic risk of developing cancer, it’s a powerful piece of information to discover. We understand that, which is why our genetic counselors carefully walk you through each step of the process.

How is genetic testing done?

Testing for breast cancer gene mutations typically requires a simple blood test. (Occasionally, technicians may use your saliva instead.) Genetic testing at Scripps Health Breast Care Centers usually asks patients to follow these steps:

  1. Get a doctor’s referral to the cancer genetic counseling department.
  2. Complete and return a family history form. (Sometimes the information you provide may show that there’s no need for genetic testing.)
  3. Schedule a one-hour appointment with a cancer genetic counselor.
  4. Submit a blood or saliva sample. You may choose to do this during the appointment with your genetic counselor or return at a later date.
  5. Receive the test results in approximately two to three weeks.
  6. Talk to your genetic counselor about the test findings and your options.

You were tested, now what?

What if I’m negative?

If your genetic test results are negative for breast cancer, you should talk to your doctor to determine whether it would still be beneficial to get more frequent clinical breast exams by a physician or nurse who is a breast care specialist.

What if I’m positive?

If your genetic test results are positive for breast cancer, you should talk to your doctor about your options. These might include:

  • Making lifestyle changes known to lower cancer risk, such as abstaining from alcohol, stopping smoking, losing weight and exercising
  • Taking a hormonal therapy medicine, such as tamoxifen, to lower your breast cancer risk
  • Increasing your clinical breast exams by a physician or a breast care specialist to every six months
  • Getting MRIs in addition to mammograms
  • Undergoing preventive (prophylactic) surgery to remove your breasts and/or ovaries before cancer develops

When you have a higher risk for breast cancer, choose a cancer care center that has experienced staff and the latest and best technologies. Learn more about what to look for in a cancer care center.

This Scripps Health and Wellness tip was provided by Kathleen Carder, Genetic Program Coordinator at Scripps in San Diego. Learn more about breast care at Scripps.