BRCA Genetic Testing for Breast Cancer

Author: Shazia Abou Talib•Reading Time: 8 Minutes

Hearing about BRCA genetic testing for breast cancer can bring several concerns at once. You may wonder whether breast cancer runs in your family, whether your children could inherit an increased risk, or whether a test result may affect your treatment.

BRCA1 and BRCA2 are among the best-known genes associated with hereditary breast cancer. However, having breast cancer does not automatically mean that you have a harmful BRCA gene change. Most breast cancers are not caused by an inherited BRCA1 or BRCA2 variant.

BRCA genetic testing may still provide important information for selected patients and families. The result can sometimes influence treatment, surgery, future screening, and whether relatives should consider testing.

Understanding what BRCA testing can and cannot reveal may help you approach the decision with greater clarity.

What Are BRCA1 and BRCA2

BRCA1 and BRCA2 are genes that normally help repair damaged DNA. They are sometimes described as tumor-suppressor genes because they help prevent cells from growing uncontrollably.

Everyone has BRCA genes. The concern is not the presence of these genes but whether one contains a harmful change, also called a pathogenic variant or mutation.

A harmful inherited change in BRCA1 or BRCA2 can increase the risk of certain cancers, including:

Female breast cancer
Male breast cancer
Ovarian cancer
Pancreatic cancer
Prostate cancer

A harmful BRCA variant increases risk, but it does not guarantee that cancer will develop. Some people with a BRCA variant never develop cancer, while many people who develop breast cancer do not have a known inherited variant.

What BRCA Genetic Testing Looks For

BRCA genetic testing for breast cancer examines DNA for harmful changes in the BRCA1 and BRCA2 genes.

The test is commonly performed using:

A blood sample
A saliva sample
A sample collected from inside the cheek

The sample is sent to a specialized laboratory. The laboratory examines the selected genes and prepares a report describing whether a harmful variant was found.

Some tests examine only BRCA1 and BRCA2. Others use a multigene panel that examines BRCA genes along with additional genes associated with hereditary breast cancer.

Before testing, it is important to understand which genes the test covers. A negative BRCA-only test does not rule out a harmful variant in another cancer-related gene.

Who May Be Offered BRCA Testing

Recommendations for genetic testing continue to evolve and may differ among medical organizations and countries.

BRCA testing may be considered when a person has a medical or family history that suggests a possible inherited cancer risk.

Examples may include:

Breast cancer diagnosed at a younger age
Triple-negative breast cancer
Cancer affecting both breasts
Male breast cancer
Ovarian, pancreatic, or certain prostate cancers in the family
Several relatives with breast cancer
A relative with a confirmed BRCA1 or BRCA2 variant
Breast cancer in more than one generation
A personal history of more than one BRCA-related cancer
Ancestry associated with a higher frequency of certain BRCA variants
Breast cancer for which genetic results may influence treatment

A person may still develop breast cancer without any family history. Families can also appear small or unaffected when there are few female relatives, limited knowledge of previous diagnoses, adoption, early deaths, or incomplete medical information.

Eligibility should not be judged from one family detail alone. A genetic counselor or another qualified professional can review the complete personal and family history.

BRCA Testing After a Breast Cancer Diagnosis

BRCA genetic testing is not only used to estimate future cancer risk. It may also be recommended after breast cancer has already been diagnosed.

A harmful BRCA result may influence decisions about:

Treatment with certain targeted medicines
Surgery involving the affected breast
Whether removal of the other breast should be considered
Ovarian cancer risk management
Future screening for additional cancers
Testing for adult relatives

A positive result does not automatically determine which surgery or treatment a patient must receive. The cancer stage, tumor biomarkers, age, overall health, previous treatments, personal preferences, and other clinical factors remain important.

Similarly, a negative BRCA result does not mean that treatment options are unavailable. It only means that the test did not identify the specific inherited BRCA finding being investigated.

BRCA Testing and Triple-Negative Breast Cancer

Triple-negative breast cancer is negative for estrogen receptors, progesterone receptors, and HER2.

Some triple-negative breast cancers are associated with inherited BRCA1 variants, but many are not. A triple-negative diagnosis does not confirm that a person has a BRCA variant.

Testing may be recommended because the result can provide information about hereditary risk and may influence treatment options in selected patients.

It is also important to understand that triple-negative and BRCA-negative describe different things.

Triple-negative describes the receptor profile of the cancer tissue.

BRCA-negative means that the genetic test did not identify a harmful variant within the genes and testing limits stated in the report.

One result cannot replace the other.

Inherited Testing and Tumor Testing Are Different

Genetic language can become confusing because BRCA changes may be investigated through both inherited genetic testing and tumor testing.

Inherited genetic testing, also called germline testing, usually examines blood or saliva. It looks for a gene change that was present from birth and may be passed through a family.

Tumor testing, also called somatic testing, examines cancer tissue. It looks for genetic changes within the tumor that may have developed during the person’s lifetime.

A BRCA change found in a tumor is not always inherited. Additional blood or saliva testing may be needed to determine whether the change is present throughout the body and could affect relatives.

Ask whether the proposed test is examining inherited DNA, tumor DNA, or both.

What a Positive BRCA Result Means

A positive result means that the laboratory identified a harmful or likely harmful variant in BRCA1 or BRCA2.

This result may indicate:

An increased risk of certain cancers
A possible influence on breast cancer treatment
A need to discuss additional screening
A reason to consider risk-reducing options
A possible inherited risk for close relatives

A person with an inherited harmful BRCA variant has a 50 percent chance of passing that variant to each biological child. The result can come from either the mother’s or father’s side of the family.

A positive result does not mean that every relative has inherited the variant. Each relative would need appropriate counseling and testing to understand their own status.

It also does not mean that preventive surgery is the only option. Screening, medication, surgery, and other risk-management choices require individualized discussion.

What a Negative BRCA Result Means

A negative result means that the test did not identify a harmful BRCA1 or BRCA2 variant within the scope of the test.

Its meaning depends on why the test was performed.

If a harmful family variant is already known and the person tests negative for that exact variant, the result may be considered a true negative. This usually means that the person did not inherit that particular family variant.

If no family variant is known, a negative result may be less conclusive. It may mean:

No harmful BRCA1 or BRCA2 variant was found
Another gene could be involved
Current testing may not identify every possible hereditary cause
The family’s cancer history may not be caused by an inherited variant
The cancer may have developed through noninherited factors

A negative BRCA test does not mean that a person cannot develop breast cancer. It also does not remove the need for appropriate screening based on age, symptoms, breast density, personal history, and overall risk.

What a Variant of Uncertain Significance Means

A report may identify a variant of uncertain significance, often shortened to VUS.

A VUS is a gene change whose effect is not yet clearly understood. Researchers do not currently have enough evidence to classify it as harmful or harmless.

A VUS is not the same as a positive result.

Major medical decisions should generally not be based on a VUS alone. Over time, the laboratory may reclassify the variant as more information becomes available.

Keep a copy of the report and ask how you will be informed if the classification changes.

Testing relatives for a VUS is not handled in the same way as testing relatives for a confirmed harmful variant. A genetics professional can explain what the finding means for the family.

How BRCA Results May Affect Treatment

For some patients with breast cancer, a harmful BRCA variant may influence treatment planning.

Certain medicines called PARP inhibitors may be used in selected patients with BRCA-associated, HER2-negative breast cancer. Eligibility depends on factors such as the stage of cancer, whether the BRCA variant is inherited, previous treatments, and other clinical findings.

A BRCA result may also influence surgical discussions. Some patients may consider more extensive breast surgery because of the risk of developing another breast cancer.

However, a positive result does not mean that a double mastectomy is required. Surgery has physical, emotional, and long-term consequences. Decisions should consider the person’s cancer diagnosis, age, health, future risk, reconstruction preferences, and personal priorities.

Testing Usually Begins With the Person Who Had Cancer

When possible, hereditary cancer testing often begins with a family member who has had a BRCA-related cancer.

Testing an affected relative may make it easier to identify whether a harmful family variant is present. If a specific variant is found, other relatives can be tested for that same change.

When no affected relative is available, an unaffected family member may still be tested. However, a negative result may be harder to interpret because there is no confirmed family variant for comparison.

This is one reason genetic counseling can be useful before testing begins.

The Role of Genetic Counseling

Genetic counseling helps patients understand the purpose, possible results, limitations, and family implications of testing.

Before BRCA genetic testing, a genetics professional may review:

Your cancer diagnosis
The ages at which relatives developed cancer
Which types of cancer occurred in the family
Whether cancer appeared on your mother’s or father’s side
Previous genetic-testing reports
Which genes should be examined
How the result could affect medical decisions
Emotional and privacy concerns

After testing, counseling can help explain whether the result is positive, negative, uncertain, or otherwise inconclusive.

Genetic information can affect more than one person. Understanding the result before sharing it with relatives can reduce confusion and unnecessary fear.

At-Home BRCA Tests Have Limitations

Direct-to-consumer genetic tests may examine only a limited number of BRCA variants.

A negative result from a limited at-home test does not rule out all harmful BRCA1 or BRCA2 variants. It also may not evaluate other hereditary cancer-related genes.

Medical decisions should not be based only on a consumer test result. A result that may affect treatment, surgery, or family testing should be confirmed and interpreted through an appropriate clinical service.

Before purchasing a test, check:

Which variants and genes are examined
Whether the laboratory meets recognized quality standards
Whether genetic counseling is available
Whether positive results require clinical confirmation
How personal genetic data may be stored or shared

Privacy and insurance protections vary between countries. Review the rules that apply where you live.

The Emotional Impact of BRCA Testing

Waiting for a genetic result can be emotionally difficult.

A patient may worry about treatment, future cancer risk, children, siblings, or the feeling of bringing difficult information into the family.

A positive result can bring fear, sadness, guilt, relief, or a sense of responsibility. A negative result can also feel complicated when the family history remains unexplained. A VUS may create frustration because it does not provide a clear answer.

Genetic results are not a judgment about anyone’s choices. No one causes an inherited gene variant, and having one does not make a person responsible for another family member’s health.

You can decide when, how, and with whom to discuss the information. A genetics professional, counselor, support group, or trusted person may help you process the result.

How Caregivers Can Help

A caregiver can provide practical and emotional support by:

Attending genetic-counseling appointments if invited
Helping collect family cancer information
Organizing test reports and medical records
Writing down the explanation of the result
Avoiding pressure about surgery or family disclosure
Giving the patient time to process the information
Helping prepare questions for the medical team

Do not assume that a positive result predicts exactly what will happen. It describes increased risk and may guide medical decisions, but it does not determine a person’s future.

Frequently Asked Questions

Does a positive BRCA test mean that I have breast cancer?

No. A positive BRCA test means that a harmful inherited gene variant was identified. It indicates increased cancer risk but does not diagnose breast cancer.

Does breast cancer always run in families?

No. Most breast cancers are not caused by an inherited BRCA1 or BRCA2 variant. A person can develop breast cancer without a family history.

Can BRCA come from the father’s side?

Yes. Harmful BRCA variants can be inherited from either the mother or the father.

Does a negative BRCA test mean that I will not develop breast cancer?

No. A negative result does not remove all breast cancer risk. Screening and evaluation should still reflect your age, symptoms, personal history, and overall risk.

Is BRCA testing only for women?

No. Men can inherit and pass on harmful BRCA variants. These variants can increase the risk of male breast cancer, prostate cancer, pancreatic cancer, and other cancers.

Can my children inherit a BRCA variant?

If you have an inherited harmful BRCA variant, each biological child has a 50 percent chance of inheriting it.

Is a VUS the same as a harmful BRCA mutation?

No. A variant of uncertain significance is a gene change whose medical importance is not yet known. It should not be treated as a confirmed harmful variant.

Can BRCA testing change breast cancer treatment?

It may influence treatment for selected patients, including possible use of certain targeted medicines. Treatment decisions also depend on the stage, tumor characteristics, previous treatment, and overall health.

Key Takeaways

BRCA1 and BRCA2 normally help repair damaged DNA.
Harmful inherited BRCA variants can increase the risk of several cancers.
Most breast cancers are not caused by an inherited BRCA variant.
BRCA genetic testing may use blood, saliva, or a cheek sample.
Testing may influence treatment, surgery, screening, and family risk assessment.
Germline testing and tumor testing answer different questions.
A positive result indicates increased risk but does not guarantee cancer.
A negative result does not remove all breast cancer risk.
A VUS is not the same as a positive result.
Other hereditary cancer genes may be examined through multigene panel testing.
At-home tests may not examine every harmful BRCA variant.
Genetic counseling can help patients and families understand the result.

References

National Cancer Institute. BRCA Gene Changes: Cancer Risk and Genetic Testing.https://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet

National Cancer Institute. Genetic Testing for Inherited Cancer Risk.https://www.cancer.gov/about-cancer/causes-prevention/genetics/genetic-testing-fact-sheet

National Cancer Institute. Cancer Genetics Risk Assessment and Counseling (PDQ), Health Professional Version.https://www.cancer.gov/publications/pdq/information-summaries/genetics/risk-assessment-hp-pdq

U.S. Food and Drug Administration. Direct-to-Consumer Tests.https://www.fda.gov/medical-devices/in-vitro-diagnostics/direct-consumer-tests

American Cancer Society. Genetic Counseling and Testing for Breast Cancer Risk.https://www.cancer.org/cancer/types/breast-cancer/risk-and-prevention/genetic-testing.html

Medical Disclaimer

This source-supported article provides reliable information to strengthen your understanding of BRCA genetic testing for breast cancer and complement personalized medical guidance from a qualified healthcare professional who understands your individual findings and history.