overview
The BRCA gene test is a blood test that uses DNA analysis to identify harmful changes (mutations) in one of two breast cancer susceptibility genes, BRCA1 and BRCA2.
People who inherit mutations in these genes have an increased risk of developing breast and ovarian cancer compared to the general population.
The BRCA gene test is offered to people who may have an inherited mutation based on a personal or family history of breast or ovarian cancer. The BRCA gene test is not routinely performed in people at average risk of developing breast and ovarian cancer.
The results of genetic tests are not always clear-cut. A positive result means that you carry a gene mutation that increases your risk of developing cancer, and you can work with your doctor to manage this risk. A negative result may mean that you do not have the mutation, or you may have a gene mutation that doctors have not yet discovered. Your test may also identify a gene variant that doctors aren't sure about. In these situations, it is not always clear what the results mean for cancer risk.
Most people who consider genetic testing undergo genetic counseling. Genetic counseling can help you understand what the results may mean for your health, help you decide if genetic testing is right for you, and recommend a specific set of genetic tests based on your family history.
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Why is this being done
The BRCA gene test is a blood test to determine if you have changes (mutations) in your DNA that increase your risk of breast cancer.
Mutations in the breast cancer gene - BRCA1 or BRCA2 - increase the risk of:
- breast cancer
- Breast cancer in men
- Cervical cancer
- Cancer of the prostate
- Pancreatic cancer
- Melanoma
If a gene mutation is found, you and your doctor can work together to manage your risk.
Who should consider BRCA gene testing?
You may be at increased risk of having an inherited gene mutation that increases your risk of breast and ovarian cancer—and a candidate for genetic testing—if you have:
- Personal history of breast cancer diagnosed before age 45
- Personal history of breast cancer diagnosed before age 50 and second primary breast cancer, one or more relatives with breast cancer, or unknown or limited family history
- Personal history of triple-negative breast cancer diagnosed at age 60 or younger
- Personal history of two or more types of cancer
- Personal history of ovarian cancer
- A personal story of male breast cancer
- Personal history of breast cancer and one or more relatives with breast cancer diagnosed before the age of 50, two or more relatives diagnosed with breast cancer regardless of age, one or more relatives with ovarian cancer, one or more relatives with breast cancer in men, or two or several relatives with prostate cancer or pancreatic cancer
- Personal History of Breast Cancer and Ashkenazi Jewish Descent (Eastern European).
- Personal history of prostate cancer or pancreatic cancer in two or more relatives with BRCA-related cancers
- A history of breast cancer at a young age in two or more relatives, such as your parents, siblings or children
- A relative with a known BRCA1 or BRCA2 mutation
- One or more relatives with a history of cancer who would meet one of these criteria for retesting
Ideally, in a family that may carry a gene mutation, a family member who has breast or ovarian cancer will first get a BRCA gene test. If this person accepts genetic testing and does not carry the BRCA gene mutation, other family members may not benefit from genetic testing. However, there may be other genetic tests to consider. A genetic counselor can help you decide what other genetic testing options may be available based on your personal and family history.
Other breast cancer genes
Scientists have identified mutations in many genes that increase the risk of breast cancer. Your doctor may also recommend testing for these gene mutations, based on your family history of cancer.
Mere information
- breast cancer
- Cervical cancer
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risks
There are no medical risks associated with testing for BRCA gene mutations other than minor risks - including dizziness, bleeding or bruising - associated with having your blood drawn. Other consequences associated with genetic testing include the emotional, financial, medical, and social implications of the test results.
If you test positive for an inherited genetic mutation, you may be exposed to:
- Feelings of anxiety, anger, sadness or depression
- Concerns related to possible discrimination by insurance companies
- Strained family relationships due to the discovery of a family genetic mutation
- Difficult decisions about preventive measures that have long-term consequences
- The feeling of inevitability that you will get cancer
On the other hand, if your BRCA mutation test is negative or the results are inconclusive — for example, you have a genetic variation but one that hasn't been linked to cancer in other people — you may experience:
- "Survivor guilt" if your family has a known gene mutation that could affect your loved ones (if you test negative)
- Uncertainty and fear that your result may not be a true negative (if your results show you have a gene variant of uncertain significance)
Your genetic counselor can help you work through your feelings and provide you and your family with support throughout the process.
How do you prepare?
The first step in the BRCA gene testing process is meeting with a genetic counselor. As soon as you are considering having genetic testing, you should meet with a genetic counselor to determine if it is right for you and to discuss the potential risks, limitations, and benefits of undergoing genetic testing.
A genetic counselor takes a detailed family and medical history, assesses cancer risk, discusses the risks and benefits of genetic testing, and presents options.
To prepare for your genetic counselor appointment:
- Gather information about your family's medical history, especially close relatives.
- Document your personal medical history, including gathering medical records from specialists or past genetic test results if available.
- Save questions for the adviser.
- Consider taking a friend or family member to help you ask questions or take notes.
It is up to you whether to continue with genetic testing after meeting with a genetic counselor.
If you decide to get a BRCA genetic test, be prepared for the emotional and social consequences of knowing your genetic status. Test results may not give clear answers about your cancer risk either, so be prepared for that as well.
What can you expect
The BRCA gene test is the most common blood test. A doctor, nurse, or medical technician inserts a needle into a vein, usually in your arm, to take a sample of blood for testing. The sample is sent to a laboratory for DNA analysis.
In some cases, other types of samples are taken for DNA analysis, including saliva. If you have a family history of cancer and are interested in getting a saliva DNA test, talk to your doctor about it. He or she can refer you to a genetic counselor who can determine the most appropriate type of sample for genetic testing.
Results
It may take several weeks for the test results to be available. You will meet with your genetic counselor to review the test results, discuss their implications, and discuss your options.
Test results can be positive, negative or inconclusive.
Positive test result
A positive test result means you have a mutation in one of the breast cancer genes, BRCA1 or BRCA2, and therefore a much higher risk of developing breast or ovarian cancer compared to someone who does not have the mutation. However, a positive result does not mean that you will definitely get cancer.
Follow-up after a positive test result may include taking specific actions to change the type and frequency of cancer screening and considering procedures and medications designed to reduce the risk of cancer. What you choose depends on many factors, including your age, medical history, previous treatments, previous surgeries and personal preferences.
Negative or uncertain test result
A negative test result means that the BRCA gene mutation has not been detected. However, it is still difficult to assess the cancer risk. The test result is only considered "true negative" if it is determined that you do not have a specific BRCA mutation that has already been identified in a relative.
A negative test result does not mean that you will definitely not get breast cancer. You still have the same cancer risk as the general population.
An equivocal result, also known as a variant of uncertain significance, occurs when the analysis detects a genetic variant that may or may not be associated with an increased risk of cancer. It is helpful to meet with a genetic counselor to understand how to interpret this finding and decide on appropriate follow-up.
New models are being developed to help determine cancer risk, with inconclusive results. Most variants of uncertain significance are ultimately reclassified as positive or negative. To be informed when this will happen, keep in touch with the doctor or genetic counselor who ordered the genetic test.
Although the BRCA gene test can detect most mutations in the BRCA1 and BRCA2 genes, you may have a gene mutation that the test was unable to detect. Or you may be at high risk for hereditary cancer if your family carries a high-risk gene mutation that researchers have not yet identified. Finally, your family may have another inherited cancer gene mutation that can be detected by other genetic tests.
Scientists continue to study gene mutations that increase cancer risk and develop new gene tests. If your genetic test was done more than five years ago, your doctor may recommend testing again with a more recent test. If your family's health history changes, such as if an additional family member develops cancer, your doctor may also recommend additional genetic testing.
By Mayo Clinic staff
12. august 2021
FAQs
What is the risk of breast and ovarian cancer with BRCA? ›
Having a BRCA mutation greatly increases the risk. The estimated risk of breast cancer in women with a BRCA mutation is 45 to 85 percent by age 70. How much do BRCA mutations increase the risk of ovarian cancer? The risk of ovarian cancer for the average American woman is about 2 percent in her lifetime.
What is the risk of ovarian cancer after breast cancer in BRCA1 and BRCA2 carriers? ›The corresponding ovarian cancer risks vary from 16% to 68% for BRCA1 and from 11% to 30% for BRCA2 carriers.
What is the rate of BRCA testing in ovarian cancer? ›Since 2010, guidelines have recommended universal testing in ovarian cancer. However, testing rates are reportedly between 10% and 30%,4 and few studies have examined commercially insured populations or identified patient-, physician-, and practice-level characteristics associated with testing rates.
Does hereditary breast cancer increase risk for ovarian? ›If you have a BRCA mutation, you are much more likely to get certain cancers: Up to a 65% risk (about 6 out of 10) for breast cancer by age 70. Up to a 39% risk (about 4 out of 10) for ovarian cancer by age 70.
What is the lifetime risk of ovarian cancer for BRCA1? ›Ovarian cancer: About 1.2% of women in the general population will develop ovarian cancer sometime during their lives (1). By contrast, 39%–44% of women who inherit a harmful BRCA1 variant and 11%–17% of women who inherit a harmful BRCA2 variant will develop ovarian cancer by 70–80 years of age (2–4).
What age does BRCA increase ovarian cancer? ›In both BRCA1 and BRCA2, the graphs show no significant increased risk of ovarian cancer until age 45. If you have a BRCA1 gene mutation, risk increases at age 45-49 and again at age 55-59. Risk increases later if you have a BRCA2 gene mutation.
What is the average age for BRCA breast cancer? ›The peak incidence of breast cancer was seen in women 41–50 years old for BRCA1 mutation carriers and those 51–60 years old for BRCA2 mutation carriers.
Can you get ovarian cancer if you don t have the BRCA gene? ›Not all families with multiple cases of breast and ovarian cancer have mutations in BRCA1 or BRCA2. There are also other genes that have been linked with an increased risk of developing breast and other cancers, such as mutations in the TP53, PTEN, CDH1, ATM, CHEK2, or PALB2 tumor suppressor genes and others.
What is the life expectancy of someone with BRCA2? ›With no intervention, the remaining life expectancy of a 30, 40 and 50 year-old BRCA1 mutation carrier who has never had cancer, is 41.5, 32.7 and 26.1 years, respectively; the remaining life expectancies of BRCA2 mutation carriers of the same ages are 48.6, 39.4 and 30.7 years.
At what age is BRCA testing recommended? ›Most health organizations recommend BRCA gene testing women who have a family or personal history from age 25. This is also the age at which it is advised to begin periodic screening for the early diagnosis of breast lesions, such as manual exams by a surgeon and imaging tests.
Is BRCA gene testing worth it? ›
This test is only recommended for those who have a strong family history of breast cancer or family history of ovarian cancer. But most people with a family history of breast or ovarian cancer—even a strong family history—do not have BRCA gene changes. Not everyone who inherits a BRCA gene change will get cancer.
What is the positivity rate for BRCA testing? ›Trends in documented BRCA testing rate among women aged 18–65 years, 2007–2016. Documented positive test results decreased from 86.1% in 2007 to 78.0% in 2017(Fig. 2). APC −0.6, 95% confidence interval −1.4–0.2).
What puts you at higher risk for ovarian cancer? ›Ovarian cancer can run in families. Your ovarian cancer risk is increased if your mother, sister, or daughter has (or has had) ovarian cancer. The risk also gets higher the more relatives you have with ovarian cancer. Increased risk for ovarian cancer can also come from your father's side.
What is the strongest risk for ovarian cancer? ›About 20 to 25 percent of women diagnosed with ovarian cancer have a hereditary tendency to develop the disease. The most significant risk factor for ovarian cancer is an inherited genetic mutation in one of two genes: breast cancer gene 1 (BRCA1) or breast cancer gene 2 (BRCA2).
Who is at high risk for breast ovarian cancer in families? ›Families from some ethnic groups are more likely to carry a gene variant that increases the risk of breast and ovarian cancer. For example, this includes families from a Central or Eastern European or Ashkenazi Jewish (Central or Eastern European Jewish) background.
What is the strongest risk factor of ovarian or breast cancer? ›Genetics: BRCA1 and BRCA2
The most significant risk factor for ovarian cancer is an inherited genetic mutation in one of two genes: breast cancer gene 1 (BRCA1) or breast cancer gene 2 (BRCA2). Inherited mutations in these genes are responsible for about 10 to 15 percent of all ovarian cancers.
There are 2 primary genes linked with most families who have HBOC: BRCA1 and BRCA2. BRCA stands for BReast CAncer. A “mutation,” or harmful genetic change, in either BRCA1 or BRCA2 gives a woman an increased lifetime risk of developing breast and ovarian cancers.
What is the correlation of breast cancer and ovarian cancer? ›The genetic link between the ovaries and the breasts
The ovaries and the breasts are also connected through a genetic component. Most notably, researchers have established that BRCA1 and BRCA2 gene mutations can increase the risk of both breast cancer and ovarian cancer.
This becomes important when counseling patients regarding options for risk reduction. Of all patients who are diagnosed with serous ovarian carcinoma, over 15% will have a germline BRCA mutation (gBRCAmut) present. Particularly noteworthy is that these patients are the incident case in the family over 40% of the time.