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 changes in the BRCA1 and BRCA2 genes. 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. So 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 the gene change. 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 doctors 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 undergo 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.
• Prostate cancer.
• Pancreatic cancer.

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

Who should consider genetic testing?

People with the following should consider genetic testing for genes that increase the risk of breast and ovarian cancers:

• A personal history of breast cancer.
• A personal history of ovarian cancer.
• A personal history of pancreatic cancer.
• A personal history of prostate cancer.
• A blood relative with a history of breast cancer, 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.

Ideally, genetic testing should be done on a family member who has had breast or ovarian cancer. If that person doesn't have gene changes, then the rest of the family might not need testing. 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.

Other breast cancer genes

Researchers have found changes in other genes that increase the risk of breast cancer. Your healthcare 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. It can be used to look for changes in the BRCA genes and other genes that increase the risk of breast cancer.

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.

People who test positive for a gene change may face:

• Feeling anxious, angry, or sad about your health and your family's health.
• Concerns over possible insurance discrimination.
• 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" that can happen 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 doctors 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 undergo 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 will discuss the potential risks, limitations and benefits of genetic testing.

The genetic counselor or other genetics professional asks detailed questions about your family and medical history. The information helps to 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 close 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.

What you can expect

The BRCA gene test is most often 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. If you have a family history of cancer and are interested in a saliva DNA test, discuss this with your healthcare 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 will meet with your genetic counselor or other health professional trained in genetics to find out your test results. You also will discuss what the results mean and go over your options.

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.

Your healthcare team will create a cancer screening plan based on your risk for cancer. You might need different screening tests or have screening more often. You also might consider medicines or surgery that can reduce your risk of cancer. Your options depend on many factors. These may include your age, medical history, past treatments and surgeries, and personal preferences.

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 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 doctors aren't sure about. This is called a variant of uncertain significance. 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 healthcare professionals understand how the gene changes might affect cancer risk. In time, most variants of uncertain significance get classified into either a positive or negative result. To be informed when this happens, stay in touch with the member of your healthcare 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 healthcare 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 additional genetic testing.

Clinical trials

Explore Mayo Clinic studies of tests and procedures to help prevent, detect, treat or manage conditions.