Genetic Testing for Breast Cancer
Breast cancer is the most common type of cancer in females in the United States. According to the American Cancer Society, about 1 in 8 females in the United States will develop breast cancer at some point in their lifetime.
One of the risk factors for breast cancer is genetics. It’s possible to inherit variations in certain genes from your parents that can increase your breast cancer risk.
It’s estimated that between 5 to 10 percent of breast cancers result from inherited gene variations. Genetic testing can help detect gene variations that raise your risk of developing breast cancer.
Learn how genetic testing for breast cancer risk works, what the results mean, and more.
How does genetic testing for breast cancer work?
Genetic testing for breast cancer risk typically uses a sample of blood, saliva, or cells from the inside of your cheek. After the sample is collected, it’s sent to a lab specializing in genetic testing to be analyzed.
Several gene variations that increase breast cancer risk have been found. The most important are those in the BRCA1 and BRCA2 genes. According to the National Cancer Institute, about 1 in 400 people have a harmful BRCA variation.
About 55 to 72 percent of females with harmful BRCA1 and 45 to 69 percent of females with harmful BRCA2 variations will develop breast cancer by age 80. Their risk of getting breast cancer in the other breast is also higher.
Other gene variants that may raise breast cancer risk include:
Gene variations that can be detected may vary by test. For example, some tests may only cover the most common variations, while others may be more extensive.
What do the results mean?
Once your sample is submitted, you’ll receive your results in 2 to 4 weeks. A healthcare professional or genetic counselor will contact you and discuss your results.
Results you can receive include:
- Positive: A known gene variation that increases your risk of breast cancer was detected.
- Negative: A known gene variation that raises your risk of breast cancer was not detected.
- Variant of unknown significance: A variant has been found in a gene, such as BRCA1 or BRCA2, but its impact on breast cancer risk is currently unknown.
Genetic testing results can be complex. Work with a genetic counselor to help understand what your results mean, so you can plan for next steps.
How accurate is genetic testing for breast cancer?
Generally speaking, genetic testing is quite accurate at detecting known genetic variants. But these tests cannot tell you whether you’ll eventually develop breast cancer.
Receiving a positive result means that, compared to the general population, you’re at an increased risk of developing breast cancer. Different gene variations can be linked to different levels of risk.
A positive result doesn’t mean that you’re certain to get breast cancer in the future. In fact, it’s possible you’ll never develop breast cancer. Your genetic counselor can give you a better idea of your breast cancer risk.
Similarly, a negative result doesn’t mean that you’ll never develop breast cancer.
Tests don’t always cover a broad range of gene variations. It’s possible that you may have a harmful variation that wasn’t covered by your test.
Continue breast cancer screenings
Breast cancer can still develop in people without an increased genetic risk.
Therefore, it’s important to continue to get regular breast cancer screenings and make lifestyle choices that can help prevent breast cancer.
Can I do genetic testing at home?
Some at-home genetic tests can help you determine breast cancer risk. These tests typically involve providing a sample of saliva or cheek cells and sending the sample by mail to be tested.
It’s recommended that you seek genetic testing from a healthcare professional rather than using an at-home test for the following reasons:
- an incomplete result: At-home tests may not cover all known variants of a gene, such as BRCA1 or BRCA2. Because of this, a negative result can be misleading.
- unnecessary alarm: At-home tests may detect common genetic variants that are only associated with a slight increase in breast cancer risk, meaning that a positive result may cause unnecessary alarm.
- genetic counseling: With genetic testing through a healthcare professional, you’ll often also have access to genetic counseling both before and after you receive your result. This can help you better understand your result in the context of your overall health.
- privacy: Your privacy may not be ensured when you use an at-home test. If you do choose to use one, carefully review a company’s disclosure policy beforehand.
Are there benefits and risks to genetic testing for breast cancer?
Getting genetic testing for breast cancer risk has several benefits. But there are some risks involved as well.
A positive result can empower you to take preventive steps, including:
- learning more about breast cancer and potential symptoms
- receiving more frequent breast cancer screenings
- making lifestyle changes that reduce your risk of breast cancer, such as being more physically active and reducing alcohol consumption
- having a preventive surgery, such as a mastectomy
- taking medications to lower breast cancer risk (chemoprevention)
Family members can also learn about their own breast cancer risk from your results. If you receive a positive result, close family members like parents, siblings, and children could have the same variation as you. This may prompt them to seek testing as well.
A negative test can give you feeling of relief or peace of mind knowing that you didn’t inherit certain variants. Meanwhile, a positive result can help you be proactive about your future and preventive steps.
Genetic testing may have a negative psychological impact for some individuals. Some people may have feelings of stress or anxiety about their future after receiving a positive or inconclusive result.
It’s also normal to feel stress or uncertainty about whether to share your results with family members. Some may not want to know. If they do ask you to share, it could cause stress or anxiety.
You may also feel guilt if genetic testing indicates that you haven’t inherited a harmful variation but other family members have.
Lastly, genetic testing for breast cancer risk may also be expensive and is not covered by some insurance plans.
Who's an ideal candidate for genetic testing for breast cancer?
Because most breast cancer isn’t caused by inherited variations, genetic testing for breast cancer risk isn’t currently recommended for the general public. Genetic testing may be recommended if you:
- have been previously diagnosed with breast cancer and:
- received your diagnosis at a young age
- have had breast cancer more than once
- are of Ashkenazi Jewish descent
- have a family history of:
- known harmful BRCA variations
- more than one family member with breast cancer, such as a mother and a sister
- breast cancer at a young age
- breast cancer in a male family member
- have a personal or family history of other cancers associated with BRCA variations, including:
If you’re concerned about inherited breast cancer risk, talk to a healthcare professional or a genetic counselor. They can help to determine if genetic testing is recommended for you.
How much does genetic testing for breast cancer cost?
The cost of genetic testing for breast cancer risk varies based on the extent of the testing. Testing for common harmful variants in BRCA1 and BRCA2 may be less expensive than a test that looks at multiple genes.
Genetic testing for breast cancer risk can cost anywhere between $300 to $5,000. Ask a healthcare professional or genetic counselor about what’s included in a test and how much it will cost.
Many health insurance plans will cover genetic testing if it’s determined to be medically necessary. It’s important to check with your insurance provider about what’s covered beforehand.
What are my next steps?
Here are the next steps you should take depending on whether you’re deciding to take a genetic test or have already received results.
- Talk to a healthcare professional.
- Speak to a healthcare professional if you’re considering genetic testing for breast cancer.
- A thorough review of your personal and family medical history can help determine if genetic testing will be useful for learning about your breast cancer risk.
- Talk to a genetic counselor. A genetic counselor can work with you to give you more information about genetic testing. This can include discussing pros and cons, what the results can and cannot tell you, and the potential impact of different results.
- Moving forward with testing ~ once you’ve taken the test, a genetic counselor can help you interpret your results. Based on your results, they’ll also recommend potential next steps.
Deciding not to test:
If you choose not to do genetic testing, continue to get regular physicals, check-ups, and breast cancer screenings.
You can also take steps in your day-to-day life to help reduce your risk of breast cancer, including:
- getting regular exercise
- limiting or avoiding alcohol
- managing your weight
- talking to a doctor about the risks and alternatives to hormone replacement therapy or oral contraceptives
The following resources may be helpful as you explore genetic testing for breast cancer:
Breastcancer.org: Breastcancer.org has a wealth of information on various topics related to genetic testing for breast cancer.
The National Society of Genetic Counselors (NSGC): A healthcare professional may recommend a genetic counselor. If not, the NSGC has a searchable database of certified genetic counselors across the country.
Genetic Testing Registry (GTR): The GTR is a searchable databaseTrusted Source that can give you specific information about the genetic tests performed by different clinical laboratories.
Facing Hereditary Cancer Empowered (FORCE): FORCE is an advocacy group for individuals that have or are concerned about inherited cancers. They offer helpful information about ways to find low-cost genetic testing.
Posted in: Genetics, In Treatment, Research, Treatment