Gene Testing for Breast Cancer: What To Expect
Q and A with Elizabeth Stark, MS, CGC - board-certified genetic counselor
Outreach and Education Manager for the Saville Cancer Screening and Prevention Center, Inova Health Systems
While over 75% of women who develop breast cancer do not have a family history of the disease, those with close blood relatives affected by breast cancer face a higher risk.
Having a first-degree blood relative (mother, sister, or daughter) with breast cancer almost doubles a woman's risk, and having two first-degree relatives with breast cancer increases her risk by about 3-fold, according to the American Cancer Society.
Understanding the genetic factors associated with breast cancer can provide valuable insights for early detection and tailored prevention strategies.
To get answers, we spoke with an expert! Elizabeth Stark, a board-certified genetic counselor at the Saville Cancer Screening and Prevention Center, helps us break down genetic mutations as a risk factor for breast cancer and steps you can take to better understand your risk.
What does it mean to inherit a genetic mutation linked to breast cancer?
Inheriting a genetic mutation linked to breast cancer means that a woman’s chance of developing breast cancer is higher than other women. Individuals with a predisposition to cancer may benefit from earlier screenings to catch a cancer at its earliest stages when it is most easily treatable. Mutations in some genes can increase a woman’s risk of developing breast cancer up to 60-80% over her lifetime.
What are the chances of inheriting a BRCA mutation?
Most cancers are not linked to a family history at all. Only about 10 to 15 percent of breast cancer is due to a genetic link. This is why it is so important for EVERY woman [starting at age 40 for average risk] to get her mammogram every single year.”
BRCA1 and BRCA2 are the most commonly discussed genes associated with breast cancer risk, but there are others that also carry an increased risk for breast cancer.
Mutations in a number of genes can result in an increased risk for breast and other cancers. (Some mutations increase risk by 55-72% vs. ~13% for women at average risk without a mutation) ACS Examples are BARD1, ATM, PALB2, PTEN, CDH1, CHEK2, TP53, , RAD51C, RAD51D, and others. ACS
What is Genetic Testing for Breast Cancer?
Genetic testing for breast cancer is a process that analyzes specific genes associated with an increased risk of developing breast cancer. It’s important that this is just one (very important!) part of a comprehensive risk assessment. Other factors that can raise your risk of developing breast cancer include breast density, alcohol consumption and when a woman first started her period or gave birth for the first time.
BRCA1 and BRCA2 are tumor suppressor genes; their job is to protect us from cancer. Everyone has two copies of BRCA1 and BRCA2, one you inherit from your mom and one from your dad. You only need one working copy of these genes to protect your cells from cancer. When someone has a mutation on one copy of one of these genes, it means that they are missing a backup copy, and the chances they will be diagnosed with breast or ovarian cancer are higher.”
Genetic Testing for Breast Cancer: The Process
Discussing genetic testing for breast cancer with your doctor is an essential step if you have concerns about your family history and genetic risk. If you are worried about a family history of breast cancer, meet with a genetic counselor.
Your genetic counselor will go over your family history in detail and also talk to you about insurance coverage and provide some guidance about what to expect from the results. Meeting with someone doesn’t mean you will definitely do testing, but it will give you a lot of information to help you make the best decision for yourself.
If you believe testing is right for you, your provider will help you decide what company to use and determine if you want to do a multi-cancer panel that addresses the risk for many types of cancer or just focus on genes associated with breast cancer risk.
The tests typically involve a blood sample or saliva swab. The sample is then sent to a laboratory for analysis. A healthcare professional, such as a genetic counselor or nurse, can administer the test. Some kits can also be done at home, administered by yourself.
The waiting time for results can vary depending on the testing company used. Typically, results are available within a few weeks. Your genetic counselor or doctor will then interpret the results and provide you with an explanation of the findings. They will discuss any potential risks and recommend appropriate screening and prevention measures based on the results.
Who should consider genetic testing for breast cancer risk?
You might consider genetic testing if:
• You or a close family member were:
○ Diagnosed with breast cancer at age 50 or younger
• Diagnosed with triple-negative breast cancer (especially if diagnosed before age 60)
• Have multiple family members with breast, ovarian, or pancreatic cancer
• A male relative has had breast cancer or
• A male relative has had prostate cancer under the age of 50.
• You are of Ashkenazi Jewish descent (which carries a higher prevalence of BRCA mutations)
A genetic counselor can help assess your risk and guide testing decisions.
Can men have BRCA mutations and be at risk for cancer too?
Yes. Men can carry BRCA mutations, which increase their risk for male breast cancer, prostate cancer, and other cancers. They can also pass the mutation to their children, so it’s important for men with a family history to consider genetic counseling too
If You Have a BRCA mutation, What Should You Do?
If you test positive for a mutation in a breast cancer gene such as BRCA1 or BRCA2, remember that you are not alone. It’s also important to know that this information has been in your body since the day you were born. The only thing that is changing is your care team’s ability to personalize your recommendations. Your care team, including doctors and counselors, is there to support you in making informed decisions about your health. There is no one-size-fits-all approach.
Genetic testing will never tell you that you have cancer or that you are definitely going to get cancer. It’s all about helping you understand your risk level so you can have the best possible outcomes.
There is no one ‘right answer’— it really comes down to figuring out what is most important to you. For some women, that looks like a high-risk screening path, alternating a mammogram with an MRI every six months. For some women, that looks like considering prophylactic surgery, such as a prophylactic mastectomy.
On the other hand, if you don't have a BRCA mutation or any other genetic mutations associated with breast cancer, it does NOT mean you should disregard regular breast cancer screenings. Early detection is vital, and all women, starting at the age of 40, should get annual mammograms and perform breast self-exams regularly.
Remember, knowledge is power. Understanding your genetic risk can empower you to take proactive steps in managing your breast health.
Have more questions? Explore Brem’s Breast Health Resources. To explore your genetics, contact a certified genetic counselor or get more resources through organizations like the National Society of Genetic Counselors or Facing Our Risk of Cancer Empowered (FORCE).
About Elizabeth Stark, MS, CGC
Elizabeth Stark, MS, CGC, is a board-certified genetic counselor specializing in working with individuals who have a personal or family history of cancer. She is the Outreach and Education Manager at the Inova Saville Cancer Screening and Prevention Center.