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Genetic Testing

Genetic test results can help you and your doctor decide if there are steps you can take to lower your cancer risk or help to guide your treatment options if you are diagnosed with breast cancer.

Most people who develop breast cancer have no family history of the disease. But people with a strong family history of breast cancer, ovarian cancer, or other cancers may have inherited an abnormal gene linked to a higher risk of breast cancer. Some people choose to have genetic testing to find out. 

Using a blood or saliva sample, a genetic test analyzes genes to see if there are any abnormalities (mutations) that may increase your risk of cancer. Genetic test results can help you and your doctor decide if there are steps you can take to lower your cancer risk or help to guide your treatment options if you are diagnosed with breast cancer.

Up to 10% of breast cancers may be hereditary, meaning they are caused by a genetic mutation inherited from a parent.

Three of the most well-known genes that can mutate and raise the risk of breast cancer are BRCA1, BRCA2, and PALB2. People who inherit a mutation in any of these genes from their mothers or fathers have a higher-than-average lifetime risk of developing breast cancer, ovarian cancer, or certain other cancers. 

Normally, the BRCA and PALB2 genes keep breast cells growing normally and prevent cancer cell growth. But when these genes contain mutations that are passed from generation to generation, they stop functioning normally and increase breast cancer risk. 

Researchers continue to discover other abnormal genes that — although less common than BRCA1, BRCA2, and PALB2 — also can raise breast cancer risk. Testing for these other gene mutations is not routine, but your doctor may recommend it based on your family history and personal situation. Talk to your doctor to see if testing for gene abnormalities besides BRCA1, BRCA2, and PALB2 makes sense for you.


Learning about your family background

If you or any of your family members have had breast cancer, you may be a candidate for genetic testing. The best way to get started is to learn more about your family history on your mother’s and father’s sides. An abnormal gene that increases breast cancer risk is more likely to run in your family if:

  • there is a history of breast and ovarian cancer in your family

  • three or more women in your family have had breast or ovarian cancer, particularly if they were diagnosed with breast cancer before age 50

  • a close relative has been diagnosed with cancer involving both breasts

  • men in your family have had breast cancer

  • there is breast cancer in your family, and either male relatives on the same side of the family have had prostate cancer at a young age, or male or female relatives on the same side of the family have had other types of cancer

  • your family is of Ashkenazi (Eastern European) Jewish descent

You may be interested in meeting with a genetic counselor — a medical professional specially trained to understand and provide information about genetics and disease. A genetic counselor works with you to build a family tree that shows all cases of breast, ovarian, and other types of cancer in your family, along with the ages at which they occurred. This visual history can help you determine whether or not genetic testing makes sense for you. Before you can build this family tree, however, you may need to do some research.

Researching your family history

As you identify possible cases of breast cancer or ovarian cancer in your family, try to confirm them with medical records and a pathology report whenever possible. 

For example, if one of your aunts died of liver cancer, it’s important to find out whether she was diagnosed with breast cancer that spread (metastasized) to the liver or with cancer that actually started in the liver. If your grandmother was diagnosed with stomach cancer, further investigation may show that it was really ovarian cancer that spread inside the abdomen, affecting her stomach.

Researching your family history can be complicated. It often requires cooperation among family members, and in some cases doctors may require relatives to sign release forms before you can access the medical information you need. 

But not all of your family members may see the usefulness of delving into past medical histories. Some may insist on maintaining their privacy, and you certainly cannot force anyone to participate. Others may be reluctant to discuss breast cancer or other types of cancer openly. Consider that, in past generations, fewer people may have been told that a family member had been diagnosed with cancer. As a result, you may not get much information when you ask about family members who have passed away.

If you were adopted as a child, researching your family history can be even more challenging. Your adoptive parents may have some medical information about your birth parents that can help you better understand your biological history.

Once you compile as complete and accurate a family history as you can, you and your genetic counselor can begin to determine whether genetic testing makes sense.


Deciding which family members should get tested

Genetic testing results are most meaningful when the process begins with a family member who has been diagnosed with breast cancer or ovarian cancer. Here’s why:

  • Even if an abnormal gene linked to higher breast cancer risk is present in your family, not every person in the family has necessarily inherited it. If one of your relatives who was diagnosed with breast or ovarian cancer also tests positive for a gene mutation, then it’s very likely that the mutated gene can cause cancers in your family. Family members who test positive for any of the three gene mutations should consider themselves to be at high risk of developing breast, ovarian, or other cancers. Family members who test negative can view their risk as similar to that of people in the general population.

  • If a family member with breast or ovarian cancer tests negative for mutations in the known BRCA1, BRCA2, and PALB2 genes, then it’s possible that a strong pattern of cancer in your family is caused by some other inherited gene yet to be identified by researchers. Based on family history alone, you and your relatives still should consider your risk of developing breast or ovarian cancer to be higher than that of the general population.

When there are no living relatives diagnosed with cancer who can undergo genetic testing, a genetic counselor can help you identify who in the family is the best person to test and why.

If someone in your family has an abnormal BRCA1, BRCA2, or PALB2 gene, it makes the most sense for that person’s closest relative to get tested.

Here are two possible scenarios:

  • If your mother’s sister has an abnormal BRCA or PALB2 gene, it makes sense for your mother to be tested next. If her test is negative for gene abnormalities, then you do not need to be tested because she could not have passed the mutation on to you. If your mother’s test is positive, you may consider whether you want to be tested next. If your mother is no longer living, then you may want to consider getting tested based on your aunt’s test result.

  • If you test positive for an abnormal gene, the next people to be tested would be your siblings or adult children. There is a chance that any of them who test positive might pass the mutation on to their own children. But if they test negative, then they can’t pass on the mutation.

A genetic counselor can advise you on which relatives should be tested (if they agree) so you can determine what is right for you and your family.

Should children have genetic testing?

Most experts advise against testing children under age 18 for abnormal BRCA and PALB2 genes because no safe, effective therapies currently exist to help prevent breast cancer in children so young. Furthermore, children are not yet old enough to decide for themselves whether they want information about their lifetime cancer risk. It is also possible that by the time today’s children reach adulthood, scientists will have discovered a new treatment to correct abnormal breast cancer genes before cancer has a chance to develop.


Genetic testing and family relationships

Genetic testing lets you determine your own personal risk of developing cancer. But your results can affect the rest of your family, too — whether or not family members wish to be tested themselves. 

While agreeing to get genetic testing can strengthen some families, it can cause friction in others, especially if some of them don’t want to be tested. But research studies have found that the process is more likely to cause positive reactions than negative ones.

Learn more about Genetic Testing and Family Relationships.

Before getting a genetic test, you must first sign an informed consent document. This document confirms that you agree to be tested and you fully understand the test’s benefits and risks.

Many testing centers require you to participate in a genetic counseling session before and after testing. Even if genetic counseling sessions are not required, it’s a good idea to ask for them. A genetic counselor can discuss the test’s benefits and risks with you and give you additional information to review.

The main benefit of testing is knowledge. If your genetic test is negative for an abnormal BRCA1, BRCA2, or PALB2 gene that you know is present in your family, then you know you are not at high risk because of a mutation in any of those genes. But you could still be at high risk because of an abnormality in an inherited gene that has not yet been linked to breast cancer or ovarian cancer. This is especially possible if a close family member has been diagnosed with breast or ovarian cancer that is not linked with mutations in these three known genes. If your genetic test is positive, you can take steps to prevent breast or ovarian cancer or try to catch these cancers early if they do develop.

Before you decide to be tested, it makes sense to discuss the pros and cons of seeking your genetic information with your family and genetic counselor. Making decisions about genetic testing is a process that takes time and thought. You may need a few sessions with your genetic counselor before you can make up your mind.

If you get a genetic test, it’s important to have a genetic counselor or other qualified healthcare professional interpret the results and discuss your health management options with you. This makes it easier for you to talk with your other doctors, so they can help you make decisions about how best to address your cancer risk.


Pros and cons of genetic testing

It’s important to consider the advantages and drawbacks of learning whether you’ve inherited an abnormal gene mutation linked with breast cancer or ovarian cancer.

Advantages of genetic testing

If one of your family members has a confirmed abnormal BRCA1 or BRCA2 gene and your test result is negative, your genetic counselor can tell you with greater certainty that you have the same relatively low risk of developing breast or ovarian cancer as people in the general population. Routine screening for breast cancer (self-exams, mammograms, doctor visits) are still important for you, just as it is for everyone. There are currently no widely accepted ovarian cancer screening guidelines for women at average risk of developing the disease. Men with a negative test result have the same extremely low risk of being diagnosed with male breast cancer as men in the general population and the same relatively low risk of being diagnosed with prostate cancer.

If your test result is positive, there are steps you can take to lower breast or ovarian cancer risk, or to detect these cancers early if they develop:

  • You may consider asking your doctor whether it makes sense for you to take a hormonal therapy medicine or an oral contraceptive. Hormonal therapy medicines, such as tamoxifen, Evista (chemical name: raloxifene), or Aromasin (chemical name: exemestane), could reduce your risk of developing breast cancer. Oral contraceptives could reduce your risk of developing ovarian cancer. While data is not clear on the safety of oral contraceptives in people who have a high risk of developing breast cancer, some doctors do recommend them for people with abnormal genes. This recommendation depends on factors that include which mutation you carry and how much breast cancer or ovarian cancer runs in your family. It makes sense to weigh the pros and cons of oral contraceptives with your doctor. You also may want to participate in a clinical trial on breast or ovarian cancer prevention to see whether other medications may be effective.

  • You also can ask your doctor whether you should have more frequent clinical exams and breast screenings — every 6 months instead of once per year — and ask for an MRI in addition to mammography. You also may wish to have regular pelvic exams and ultrasounds, and possibly a blood test called CA-125, which detects any early signs of ovarian cancer.

  • You may consider preventive surgical removal of your breasts, ovaries, or both to lower cancer risk (called prophylactic surgery).

  • If you are diagnosed with breast or ovarian cancer, you and your doctor can make treatment decisions that take your genetic information into account.

  • If you get genetic testing as part of a clinical trial, you are contributing to research that could eventually help to prevent or cure breast or ovarian cancer.

  • If you learn that you carry an abnormal gene linked to breast cancer, you and maybe even your family members may be inspired to make lifestyle and family planning changes or other decisions that could help lower your cancer risk.

Men who test positive for an abnormal BRCA1 or BRCA2 gene are considered to be at higher-than-average risk for developing prostate cancer. Men with one of these gene mutations may consider asking their doctors about beginning screenings, including an annual digital rectal exam and prostate-specific antigen (PSA) blood test, particularly if they are between 40 and 50 years old. It’s a good idea for men with a BRCA mutation to begin prostate cancer screening at age 40. Their risk of developing male breast cancer is still relatively low, but higher than it is for men who do not have an abnormal gene. It’s also important that men report any unusual breast changes or lumps to their doctors immediately.

Drawbacks of getting genetic testing

While there are steps you can take to lower breast cancer risk if your genetic test results are positive, there are some limitations to keep in mind:

  • Removing the breasts and ovaries lowers cancer risk dramatically. But surgery does not get rid of every breast- and ovary-related cell, so it does not entirely eliminate risk. In fact, after having preventive surgery to remove the breasts, ovaries, or both, it’s important to keep getting monitored regularly to ensure nearby tissues and organs remain cancer-free.

  • Normal test results don’t guarantee healthy genes. Many women in a single family may have been diagnosed with breast cancer despite testing negative for a known breast cancer mutation. The breast cancer may be caused by an inherited gene abnormality that researchers simply haven’t identified yet. Additionally, someone who tests negative for known mutations is still considered high risk if there’s no confirmation of a known mutation in a family member diagnosed with cancer. It’s essential that people in this situation getting monitored regularly.

  • You may still not be able to detect breast or ovarian cancer early even if you are closely monitored with regular exams and screenings. Some women are diagnosed with later-stage disease despite the best surveillance techniques.

  • Testing positive for a known gene mutation linked to breast or ovarian cancer can trigger anxiety, depression, or anger in some people. But testing positive for an abnormal gene doesn’t necessarily mean you’re definitely going to be diagnosed with cancer. If you think knowing that you have a gene mutation may be too difficult for you emotionally, you may consider delaying genetic testing until more is known about how to prevent and treat the disease.

  • Some people may feel guilty or worried if they learn they’ve passed on an abnormal gene to their children. It’s important to remember that having this information also may prepare you for helping your children cope with their genetic information.

  • Some people may worry they might face discrimination because of their genetic information if they try to get life insurance coverage or a job. So far, however, discrimination related to genetic information has not proven to be a major problem. In 2008, the Genetic Information Nondiscrimination Act (GINA) was signed into law. GINA protects Americans from being discriminated against by health insurers and potential employers because of their genetic information.

  • Genetic testing may not answer all your questions. There may be other factors contributing to high cancer risk that researchers do not yet understand or know about.


How to prepare for genetic counseling

If you’re thinking about getting a genetic test to see if you have a cancer-related mutation, the best first step is to schedule an appointment with a genetic counselor.

Learn more about preparing for genetic counseling.


Questions to ask your genetic counselor

When you meet your genetic counselor for the first time, you can expect to answer questions about your personal medical history, whether you’ve been diagnosed with breast cancer or other cancers, and whether anyone on either side of your family has been diagnosed with cancer. But the first meeting also is the perfect opportunity for you to ask your genetic counselor any questions you may have.

Here are 12 questions to help get you started.


Genetic testing facilities and costs

You can get a genetic test in your doctor’s office to see if you have inherited an abnormal BRCA1, BRCA2, or PALB2 gene mutation. The doctor takes a blood or saliva sample and sends it to a commercial laboratory, or sometimes a research testing facility. During testing, the genes are separated from the rest of the DNA and scanned for abnormalities.

Whether the genetic test is handled by a research testing facility depends on the type of test and the specific genes being tested. Research laboratories tend to perform free and anonymous tests. But research laboratories may provide limited results or require multiple family members to participate. It also may take many months or years for test results to be ready, if they are ever made available at all.

In the United States, several laboratories conduct commercial BRCA1, BRCA2, and PALB2 testing, including Myriad Genetic Laboratories, Ambry Genetics, and GeneDx. These facilities report results in two to four weeks. 

The most common causes of hereditary breast cancer are BRCA1 and BRCA2 mutations. But abnormalities in other genes also have been associated with breast cancer risk. 

Still, PALB2 and other breast cancer gene abnormalities appear to be a less common cause of breast cancer, although testing for many of these genes is also now available. People who have genetic testing may choose to be tested for only the BRCA1 and BRCA2 genes or for multiple breast cancer-related genes as part of a panel test. Testing costs range from approximately $300 to $5,000, depending on whether you get tested for specific areas of known abnormal genes or for hundreds of areas within multiple genes.

Different types of genetic abnormalities are detected by different testing methods. Therefore, it’s important to be aware of the technical type of test you are getting. Gene sequencing detects a majority of genetic mutations. But this test method cannot detect large mutations or genetic rearrangements that may occur within genes. Therefore, experts recommend testing genes for large-scale mutations. 

Most laboratories that offer genetic testing perform both types of tests at the same time. If you’ve gotten a genetic test and aren’t sure whether the laboratory screened for large-scale mutations, ask the physician or genetic counselor who ordered the test. It’s a good idea to find out what tests the laboratory completed and whether you are eligible for any additional testing.

Although many insurance plans cover genetic testing, it’s smart to confirm whether your insurance plan does.

In 1988, the U.S. Congress passed the Clinical Laboratory Improvement Amendments (CLIA) to ensure quality standards and the accuracy and reliability of results across all testing laboratories, with the exception of research facilities. Genetic testing should be performed by a CLIA-approved facility.


Types of genetic tests

There are many different types of genetic tests you can take. A genetic counselor can help you decide which test is right for you.

Learn more about the different types of genetic tests.


Getting genetic test results

A critical part of genetic risk assessment is the responsible and sensitive disclosure of test results. Typically, the laboratory sends your test results to your doctor or genetic counselor so either of them can explain the results to you. 

Learn more about getting genetic test results.


Genetic testing and privacy

Genetic testing isn’t anonymous. Your name appears on the test order and the results, which then become part of your medical record. The testing company is not allowed to reveal your results to anyone except your doctor or genetic counselor. Although medical records are confidential, many people worry they may be discriminated against by employers or health insurers if they get a positive genetic test result — one that suggests an increased cancer risk.

If you are a U.S. citizen, the 2018 Genetic Information Nondiscrimination Act (GINA) protects you from being discriminated against by health insurers and potential employers because of your genetic information. But GINA does not apply to small companies with fewer than 15 employees or to the U.S. military. GINA also does not apply to life insurance, disability insurance, or long-term care insurance, so it’s recommended that people secure these types of insurance plans before getting a genetic test.

It makes sense for residents of other countries to find out what their legal rights are. For example, many European nations have passed nondiscrimination laws like GINA.

People who are concerned about their privacy sometimes prefer to pay for the test themselves and submit their blood samples under a code number or an assumed name. But Cristina Nixon, MS, LCGC, a licensed certified genetic counselor with the Cancer Risk Assessment and Genetics Program at Main Line Health in Pennsylvania, recommends you use your real identity and go through your health insurance plan. She notes that the point of finding out whether you have an abnormal gene mutation is to take action. Based on a positive test result, it makes sense to have more frequent cancer screenings, take risk-reducing medications such as tamoxifen, or have risk-reducing surgery, such as a mastectomy


Why Community members chose genetic testing

We asked members of the Community to share why they chose to have genetic testing and how the results affected their lives and treatment choices.

Read To Test or Not to Test? Real Women on Why They Chose Genetic Testing.


How to find a genetic counselor

To find a genetic counselor who specializes in familial cancer risk, talk to your doctor or check with the hospitals and cancer centers in your area. 

You also can contact the National Cancer Institute Cancer Genetics Services Directory at (1-800-4-CANCER) or the National Society of Genetic Counselors at (312-321-6834).

For more in-depth information about hereditary cancer, genetic testing, counseling, and support, visit FORCE (Facing Our Risk of Cancer Empowered), a partner.

— Last updated on July 27, 2022, 1:57 PM