BRCA gene test for breast and ovarian cancer risk

Overview

The BRCA gene test looks for DNA changes that increase the risk of breast cancer and ovarian cancer. It uses a sample of blood or saliva to look for the changes.

DNA is the genetic material inside cells. It holds the instructions, called genes, that tell cells what to do. Harmful changes in the genes can increase the risk of cancer. Healthcare professionals sometimes call these gene changes variants or mutations.

The BRCA gene test looks for harmful changes in the BRCA1 and BRCA2 genes. Harmful changes in each cause a similar increase in breast cancer risk. Harmful changes in each also increase the risk of ovarian cancer. However, the risk of ovarian cancer with harmful changes in BRCA1 is higher than with BRCA2. Harmful changes in both BRCA1 and BRCA2 increase the risk of prostate and pancreatic cancers too. Other genes also can increase the risk of breast and ovarian cancer. Some genetic tests look for these other genes in addition to the BRCA genes. A genetic test that looks at many different genes is called a multigene panel test.

A healthcare professional can help you decide whether genetic testing is right for you. The gene changes that increase the risk of breast and ovarian cancer are passed from parents to children. The health professional considers your personal and family history of cancer when making a recommendation. Genetic testing isn't routinely done on people with an average risk of breast and ovarian cancer.

The results of genetic testing aren't always clear. A positive result means you carry a gene change that increases your risk of cancer. You can work with your healthcare team to manage that risk. A negative result may mean that you don't have harmful gene changes. It also may mean that you might have a gene change that hasn't been discovered yet. Your test also might find a gene change that healthcare professionals aren't certain about. In these situations, it's not always clear what the results mean for your cancer risk.

Most people considering genetic testing have genetic counseling. Genetic counseling can help you understand what the results could mean for your health. It also can help you decide whether genetic testing is right for you.

Why it's done

The BRCA gene test looks for DNA changes that increase the risk of breast cancer and ovarian cancer. BRCA1 and BRCA2 are the most well-known genes. Testing often looks for those genes and many other genes that increase the risk of breast and ovarian cancers.

Changes in these genes significantly increase the risk of many cancers, including:

• Breast cancer.
• Male breast cancer.
• Ovarian cancer.
• Pancreatic cancer.
• Prostate cancer.

If you have a harmful gene change, you and your healthcare team can work together to manage your risk.

Who should think about genetic testing?

Men and women can carry and pass down changes in BRCA1, BRCA2 and other genes that increase the risk of breast and ovarian cancers. So anyone with the following should consider genetic testing for these genes:

• A personal history of breast cancer, especially breast cancer at age 65 or younger or a triple-negative breast cancer.
• A personal history of ovarian cancer.
• A personal history of pancreatic cancer.
• A personal history of prostate cancer.
• A blood relative, such as a brother, sister, parent, grandparent or cousin, with a history of breast cancer, especially at age 50 or younger, or male breast cancer.
• A blood relative with ovarian cancer, pancreatic cancer or prostate cancer.
• A blood relative who had genetic testing and was found to have a gene change that increases the risk of breast cancer. Blood relatives may be offered testing for the same gene change.
• Ashkenazi Jewish ancestry, with or without a family history of cancer.

Ideally, genetic testing should first be done in a family member who has had breast or ovarian cancer:

• If the family member doesn't have a harmful gene change, then the rest of the family might not need testing for that gene change. However, there might be other genetic tests to consider. A genetic counselor or other healthcare professional trained in genetics can help you decide what test might be best.
• If the family member has an inherited harmful BRCA1 or BRCA2 gene change, other blood relatives may be offered testing to see whether they carry that same specific gene change. First-degree relatives — such as parents, siblings and children — generally have a 1 in 2 chance of having the same gene change. Sharing this information may help multiple family members and future generations understand their cancer risk and decide whether to consider genetic counseling or testing.

BRCA testing usually is not recommended for children under age 18. This is because BRCA gene-related cancers usually happen in adults. Also, children usually do not need to take steps to lower their cancer risk during childhood.

Other breast cancer genes

Researchers have found changes in other genes that increase the risk of breast cancer. Your care team might recommend testing for these gene changes, too, based on your family history of cancer. This is known as multigene panel testing. A multigene panel test looks for changes in many different genes. A multigene panel test can be helpful when no specific harmful family gene change is known or when the pattern of cancer in a family could be linked to more than one inherited cancer syndrome.

A multigene panel test can find inherited changes in the BRCA genes and other genes that increase the risk of breast or ovarian cancer. Examples include PALB2, TP53, PTEN, CDH1, STK11, ATM, CHEK2, BARD1, BRIP1, RAD51C and RAD51D.

A genetic counselor or another healthcare professional trained in genetics can help choose a test that includes the genes most likely to matter for your personal and family history. Most insurance plans cover at least a portion of the cost of BRCA testing for those who qualify. Coverage often is based on personal and family medical history.

Risks

There's no medical risk associated with the BRCA gene test or any other genetic test that looks for a risk of breast and ovarian cancers. Having blood drawn for the test carries some minor risks. These may include bleeding, bruising and lightheadedness. Other effects of genetic testing include the emotional, financial, medical and social implications of your test results.

If you test positive for a harmful gene change, you may face:

• Feeling anxious, angry, or sad about your health and your family's health.
• Concerns over possible unfair treatment by insurers.
• Strained family relationships.
• Difficult decisions about the steps to take to prevent cancer.
• Coping with the worry that you'll eventually get cancer.

There also may be some emotional concerns if you test negative or if you receive results that aren't clear-cut. In these situations, there may be:

• "Survivor guilt" if family members have positive results and you don't.
• Uncertainty and concern that your result may not be a true negative result. This can happen if your results show you have a gene change that healthcare professionals aren't sure about.

Your genetic counselor or another professional trained in genetics can help you work through any of these feelings. That person can provide you and your family support throughout this process.

How you prepare

The first step in the BRCA gene testing process is to have genetic counseling. To do this, you meet with a genetic counselor or another healthcare professional trained in genetics. This person can help you understand whether testing is right for you and which genes should be tested. You also discuss the potential risks, limitations and benefits of genetic testing.

The accuracy of genetic testing depends partly on what the test is designed to find. Genetic tests look for the harmful gene changes included in the test. But different tests look for different gene changes. A genetics professional can help make sure the test ordered looks for the gene changes most likely to matter based on your personal and family history.

The genetic counselor or other genetics professional asks detailed questions about your family and medical history. The information helps assess your risk of having an inherited gene change that increases the risk of cancer.

To prepare for your meeting with the genetics professional:

• Gather information about your family's medical history, especially that of blood relatives.
• Document your personal medical history. This includes collecting records from specialists or results of previous genetic testing, if available.
• Write down questions to ask about genetic testing.
• Consider having a friend or family member come with you. That person can help ask questions or take notes.

It's up to you whether you choose to have genetic testing.

If you decide to have genetic testing, prepare yourself. Consider the emotional and social effects that learning your genetic status might have. Test results also may not provide you with clear-cut answers regarding your cancer risk. So prepare to face that possibility too.

At-home genetic test kits purchased online without talking with a healthcare professional may come with limitations. These kits may not look for all harmful BRCA1 or BRCA2 changes or for other genes that can increase the risk of breast and ovarian cancer. For example, one direct-to-consumer test checks for three harmful BRCA variants even though hundreds of BRCA variants can increase cancer risk. This means a negative result from an at-home test may not rule out an inherited cancer risk. If you are considering at-home testing, talk with a genetic counselor or another healthcare professional trained in genetics to make sure you get the right test and understand what the results mean.

What you can expect

The BRCA gene test is most often done as a blood test. A member of your healthcare team inserts a needle into a vein, usually in your arm. The needle draws out the blood sample. The sample goes to a lab for DNA testing.

Sometimes other sample types are collected for DNA testing, including saliva or a swab of cells from inside the cheek. If you are interested in a saliva or another DNA test, discuss this with your care team. A genetic counselor or other health professional trained in genetics can tell you the best sample type for your genetic testing.

Results

The results of a BRCA gene test may take a few weeks to come back. You meet with your genetic counselor or other health professional trained in genetics to find out your test results. You also discuss what the results mean and go over your options. Genetic testing is most useful when the results are reviewed along with your personal history, family history and goals for care.

Your test results may be positive, negative or uncertain.

Positive test result

A positive test result means that you have changes in a gene that are associated with a higher risk of cancer. But a positive result doesn't mean that you're certain to develop cancer.

After testing positive for a BRCA gene change or another gene change that could increase cancer risk, your healthcare team creates a care plan. The care plan depends on many factors. These may include the gene change found, your age, your medical history, past treatments and surgeries, and your personal preferences. After a positive BRCA test, next steps could include one or more of the following:

• Cancer screening that starts earlier or happens more often. For increased breast cancer risk, this may include mammograms and breast MRI. For men with harmful BRCA gene changes, recommendations may include mammograms for male breast cancer screening and prostate cancer screening. Some people with harmful BRCA gene changes and a family history of pancreatic cancer also may think about pancreatic cancer screening.
• Medicines. Some people may talk with their care teams about medicines as part of a plan to lower cancer risk. For breast cancer risk, options may include medicines such as tamoxifen or raloxifene. These medicines can lower breast cancer risk in women at higher risk because of a personal or family history. It's less clear how much they help prevent a first breast cancer in people with a strong inherited BRCA risk. For people with harmful BRCA1 or BRCA2 gene changes who already have had breast cancer, tamoxifen may help lower the chance of a new cancer in the other breast. To lower ovarian cancer risk in people with harmful BRCA1 or BRCA2 gene changes, oral contraceptives may help, but they can have possible harms. Talk with your care team about the benefits and risks before using medicine to lower cancer risk.
• Bilateral mastectomy surgery. To lower the risk of a future breast cancer, some people may consider surgery to remove both breasts. This is called bilateral risk-reducing mastectomy.
• Salpingo-oophorectomy surgery. There is no screening test proved to find ovarian cancer early enough to improve long-term survival. People with harmful BRCA1 or BRCA2 gene changes may choose surgery to remove the ovaries and fallopian tubes. This is called risk-reducing salpingo-oophorectomy. Some people also may talk with their care teams about whether to remove the uterus at the same time. This is called hysterectomy. The timing of this surgery and whether to have a hysterectomy depend on many factors. These include age, plans for pregnancy, menopause concerns and personal preferences.
• Reproductive planning. If you desire to have children, your care plan may include reproductive planning. If you have not gone through menopause and have harmful BRCA1 or BRCA2 gene changes, you may choose to have your fallopian tubes removed first and your ovaries removed later. Ovarian cancer often starts in the fallopian tubes. This approach is being studied. People who choose it usually are advised to have the ovaries removed later to lower ovarian cancer risk more fully.
• Genetic testing for blood relatives. If you have a harmful BRCA1 or BRCA2 gene change, your parents, siblings and children may have a chance of having the same gene change. Sharing this information may help family members and future generations decide whether to consider genetic counseling or testing. If your blood relative has a harmful BRCA1 or BRCA2 gene change, you may be offered testing for that same gene change. A genetic counselor or other health professional trained in genetics can help you understand what your relative's result may mean for you and your family and your future healthcare needs.
• Cancer treatment. If you already have cancer, genetic test results may help your care team choose cancer treatments or find clinical trials that may be right for you.

Negative or uncertain test result

A negative test result means that no gene changes were found. However, you could still have a higher risk of cancer.

A negative result is considered a "true negative" only if it finds that you don't carry the specific harmful gene change that runs in your family. This type of negative test result means you have the same cancer risk as the general population.

An uncertain test result might happen if your results show a gene change that healthcare professionals aren't sure about. This is called a variant of uncertain significance (VUS). A genetic counselor or other healthcare professional trained in genetics can help you understand this result.

Researchers continue working to discover new gene changes. The research helps health professionals understand how the gene changes might affect cancer risk. In time, many variants of uncertain significance are reclassified. Most are later found not to increase cancer risk. To be informed when this happens, stay in touch with the member of your care team who ordered your genetic test.

Genetic testing is an active area of research. If your gene test was done more than five years ago, your care team might recommend testing again with newer tests. If your family health history changes, such as if additional family members develop cancer, your team also might recommend more genetic testing.