BRCA1 and BRCA2 (BReast CAncer genes 1 and 2) are the best-known genes linked to breast cancer risk.
This section provides information on BRCA1/2 gene mutations and how they impact cancer risk, breast cancer screening recommendations and options for lowering breast cancer risk. It also has information on genetic testing and other topics.
Learn about BRCA1/2 gene mutations in women.
Learn about BRCA1/2 gene mutations in men.
Every cell in your body contains genes. Genes contain the blueprints (genetic code) for your body.
For example, genes contain the information that determines the color of your eyes. They also contain information that affects how the cells in your body grow, divide and die.
The information in your genes is passed on (inherited) from both your mother and your father. And, you can pass this information on to your children (both your daughters and sons).
Some changes in the genetic code that affect the function of the gene are called mutations. Mutations are rare.
Just as with other information in genes, mutations can be passed on from a parent to a child.
You get half of your genes from your mother and half from your father. So, if your mother has a BRCA1 gene mutation, there’s a 50 percent chance you will also have a BRCA1 mutation.
Many inherited gene mutations have little or no effect on health (good or bad). Others can increase the risk of certain diseases, including breast cancer.
In the U.S., 5-10 percent of breast cancers are related to an inherited gene mutation [4,27].
Learn more about inherited gene mutations.
Everyone has BRCA1 and BRCA2 genes. Some people have an inherited mutation in one or both of these genes that increases the risk of breast cancer.
BRCA1/2 mutations can be passed to you from either parent and can affect the risk of cancers in both women and men.
A person who has a BRCA1/2 mutation is sometimes called a BRCA1/2 carrier.
Like other gene mutations, BRCA1/2 mutations are rare in the general population. In the U.S., about 1 in 400 people have a BRCA1/2 mutation .
Prevalence varies by ethnic group. Among Ashkenazi Jewish women and men, about 1 in 40 have a BRCA1/2 mutation .
The table below shows the prevalence of BRCA1/2 mutations in women diagnosed with breast cancer by ethnic group (in alphabetical order).
Prevalence of BRCA1/2 mutations among U.S. women with breast cancer by ethnic group (in alphabetical order)
Less than 1%
Data not available
White (non-Ashkenazi Jewish)
Adapted from National Cancer Institute materials and Malone et al. [27,176].
Read our blog about breast cancer in men.
Men can have BRCA1 and BRCA2 gene mutations and can pass them on to their children.
Men who have a BRCA2 mutation have an increased risk of breast cancer [28-29,30,37].
For example, the lifetime risk of breast cancer (up to age 80) is [32-35]:
While 5-10 percent of breast cancers in women are thought to be due to gene mutations, up to 40 percent of breast cancers in men may be related to BRCA2 mutations .
This means men who get breast cancer are more likely to have an inherited gene mutation than women who get breast cancer.
Men who have a BRCA1 mutation may also have an increased risk of breast cancer, but this link is less clear .
Learn more about breast cancer in men.
Learn about breast cancer screening for men with a BRCA1/2 gene mutation.
Men who have a BRCA1/2 mutation have an increased risk of prostate cancer [27,30,32,35,187].
The lifetime risk of prostate cancer is [35,188]:
Learn about prostate cancer screening for men with a BRCA1/2 gene mutation.
BRCA1/2 carriers also have an increased risk of pancreatic cancer and some second primary cancers (new cancers that develop after a first breast cancer) .
BRCA1/2 mutations may also increase the risk of other cancers . However, data are limited and these topics are still under study.
For a summary of research studies on BRCA1/2 mutations and breast cancer, visit the Breast Cancer Research Studies section.
Genetic testing gives people the chance to learn if their breast cancer is due to an inherited gene mutation.
The National Comprehensive Cancer Network (NCCN) recommends all men diagnosed with breast cancer have genetic testing for BRCA1/2 mutations .
Learn more about genetic testing.
Cancer screening tests are used to find cancer in a person who has no warning signs or symptoms.
Cancer screening recommendations for men who are BRCA1/2 carriers are different from recommendations for women who are BRCA1/2 carriers.
Although not recommended for all men, the NCCN recommends breast cancer screening for men who have :
For men who fall into one of the groups above, the NCCN recommends, starting at age 35 :
Men at higher risk for breast cancer should also be aware of the warning signs of breast cancer.
The NCCN recommends, starting at age 45 :
Many risk factors for breast cancer in men are different from those in women.
Whether the risk factors for breast cancer in men with a BRCA1/2 mutation are the same as those for men without a mutation has not been well studied.
Learn about risk factors for breast cancer in men.
Some support groups are tailored to people with BRCA1/2 gene mutations and those with BRCA1/2-related breast cancers.
Our Support section offers a list of resources to help find local and online support groups.
SUSAN G. KOMEN® SUPPORT RESOURCES
BreastCancerTrials.org in collaboration with Susan G. Komen® offers a custom matching service to help you find clinical trials for people with BRCA1/2 or other gene mutations.
You can also visit the National Institutes of Health's website to find a clinical trial.
Learn more about clinical trials.
If you or a family member has a BRCA1/2 gene mutation, you may have questions about what this means for you. Learn more about:
Women who have a BRCA1 or BRCA2 gene mutation have an increased risk of breast cancer [28-30].
Estimates of risk are different for BRCA1 carriers and BRCA2 carriers. By age 70, the chance of developing breast cancer is [27,29-30]:
Women in the general population have about a 7 percent chance of getting breast cancer by age 70 . (The lifetime risk of breast cancer is about 12 percent .)
This means by age 70:
These numbers represent average risk, so the risk of breast cancer for any one woman with a BRCA1/2 mutation may fall outside this range.
Note these risks are not 100 percent. Many women with a BRCA1/2 mutation will never have breast cancer [28-30]. A combination of factors likely causes breast cancer.
BRCA1/2 mutations are thought to explain a large portion of hereditary breast cancers .
Most breast cancers, however, are not related to inherited gene mutations.
Learn about risk-lowering options for women at higher risk.
Learn about genetic testing.
Breast cancers related to BRCA1 mutations tend to be triple negative [27,177-178]. Triple negative breast cancers are:
BRCA2 carriers tend to have breast cancers that are estrogen receptor-positive (ER-positive) [27,177-178].
Learn about hormone (estrogen and progesterone) receptor status, HER2 status and other factors that affect prognosis and treatment.
A BRCA1/2 mutation can increase the risk of a second primary breast cancer (a second breast tumor not related to the first one) [179-184].
These tumors usually occur in the contralateral (opposite) breast rather than in the same breast as the first cancer.
For BRCA1/2 carriers, the chance of a contralateral breast cancer 10 years after diagnosis of the first cancer is about 10-30 percent compared to about 5-10 percent for women without a BRCA1/2 mutation diagnosed with breast cancer [179-185].
The lifetime risk of a second primary contralateral breast cancer is about 40-70 percent for BRCA1/2 carriers [182,185].
BRCA1/2 carriers diagnosed with breast cancer in one breast may consider contralateral prophylactic mastectomy to reduce the risk of a second primary breast cancer in the opposite breast [175,202]. This should be discussed with a health care provider.
For a summary of research studies on BRCA1/2 mutations and breast cancer, visit the Breast Cancer Research Studies section.
There are options for women with BRCA1/2 gene mutations to lower their risk of breast cancer.
BRCA1/2 mutations increase a woman's risk of ovarian cancer .
The lifetime risk of ovarian cancer (up to age 70) is :
Although BRCA1/2 carriers have a higher risk of ovarian cancer than non-carriers, this does not mean carriers have a worse prognosis if they are diagnosed.
BRCA1/2 carriers who get ovarian cancer appear to have better survival than non-carriers in the first 5 years after diagnosis . One reason for this improved survival may be that BRCA1/2-related ovarian cancers appear to have a better response to chemotherapy than other ovarian cancers [289-290].
Long-term data on survival in BRCA1/2 carriers diagnosed with ovarian cancer are limited.
BRCA1/2 carriers can reduce their risk of both ovarian and breast cancer by having prophylactic oophorectomy (surgical removal of the ovaries) .
Prophylactic oophorectomy may also lower the risk of breast cancer .
BRCA1/2 gene mutations increase the risk of prostate cancer (in men) and pancreatic cancer . They also increase the risk of a second primary breast cancer in the opposite (contralateral) breast [27,185]. These are new breast cancers that develop after a first breast cancer.
BRCA1/2 mutations may also increase the risk of other cancers .
For a summary of research studies on BRCA1/2 mutations and cancer, visit the Breast Cancer Research Studies section.
With treatment, women with a BRCA1 or BRCA2 mutations appear to have similar breast cancer survival as women without BRCA1/2 mutations [291-292].
In general, breast cancers related to BRCA1 and BRCA2 mutations are treated in the same way that breast cancers not related to BRCA1/2 mutations are treated.
However, some drug therapies may be more effective in treating BRCA1/2-related breast cancers than other breast cancer .
At this time, the PARP inhibitors olaparib (Lynparza) and talazoparib (Talzenna) are used to treat some BRCA1/2-related metastatic breast cancers.
Platinum-based chemotherapy drugs (such as carboplatin) may be better at treating BRCA1/2-related breast cancers than other breast cancers [294-296]. This is under study.
Learn more about emerging areas in drug therapies for early breast cancer.
Learn more about emerging areas in drug therapies for metastatic breast cancer.
Genetic testing gives people the chance to learn if their breast cancer or family history of breast cancer is due to an inherited gene mutation.
Most women who get breast cancer do not have a BRCA1 or BRCA2 gene mutation.
BRCA1/2 is only recommended for people with a high risk of having a BRCA1/2 gene mutation, including those with :
In most cases, testing is first done on the person with breast, ovarian, pancreatic or aggressive prostate cancer.
Just because one person in the family has a mutation doesn’t mean everyone in the family has the mutation. Only identical twins have the exact same genes. Other family members share some, but not all, of their genes.
For example, if your mother has a BRCA1 gene mutation, there’s a 50 percent chance you will also have a BRCA1 gene mutation (you get half of your genes from your mother and half from your father).
A health care provider or genetic counselor can help you decide whether genetic testing is right for you and your family.
Testing for a BRCA1/2 mutation only requires a blood or saliva sample, but the risks and benefits should be considered before testing. There can be physical, emotional and financial impacts of knowing your genetic status.
Testing costs are usually covered by health insurance for people who fall into one of the categories above (for whom genetic testing is recommended).
Learn more about genetic testing.
Breast cancer screening tests are used to find cancer in a person who has no warning signs or symptoms.
BRCA1 and BRCA2 carriers need to be screened for breast cancer starting at an earlier age and more frequently than other women. They should also be aware of the warning signs of breast cancer.
The National Comprehensive Cancer Network (NCCN) recommends :
Clinical breast exam
Under age 25
Every 6-12 months
Only if breast MRI not available: Every year
Ages 30 and older
Learn more about breast cancer screening recommendations for women at higher risk.
For a summary of research studies on breast MRI plus mammography versus mammography alone for women at higher risk of breast cancer, visit the Breast Cancer Research Studies section.
Most risk factors for breast cancer in women likely impact risk in the same way in BRCA1/2 carriers and non-carriers.
For example, exercise and breastfeeding appear to decrease the risk of breast cancer in both BRCA1/2 carriers and non-carriers [190-191].
However, certain reproductive and lifestyle factors may affect risk in BRCA1/2 carriers differently than in non-carriers.
Very low doses of radiation (such as from X-rays) don't have much, if any, impact on breast cancer risk.
While the radiation during mammography can increase the risk of breast cancer over time, this increase is very small [196-197].
For BRCA1/2 carriers however, there's some concern the radiation exposure from screening mammography before age 30 may increase breast cancer risk more than for other women .
This issue is under active study.
Women who have a BRCA1 or BRCA2 gene mutation have medical options to help lower their risk of breast cancer:
If you are a BRCA1/2 carrier, talk with your health care provider about the pros and cons of these options.
Take the time to make decisions that are right for you. Don’t feel you need to rush.
For women at high risk of breast cancer, tamoxifen and raloxifene can lower the risk of :
Tamoxifen and raloxifene only reduce the risk of estrogen receptor-positive breast cancers. Neither drug reduces the risk of estrogen receptor-negative cancers .
Both pre- and postmenopausal women can take tamoxifen. Only postmenopausal women can take raloxifene.
Tamoxifen is more effective than raloxifene in lowering breast cancer risk, but raloxifene has fewer harmful side effects . This makes raloxifene a better choice for some women.
Learn more about the side effects of tamoxifen and raloxifene.
For a summary of research studies on the use of tamoxifen and raloxifene to reduce the risk of breast cancer, visit the Breast Cancer Research Studies section.
Learn more about risk-lowering drugs.
Bilateral prophylactic mastectomy is the removal of both breasts to prevent breast cancer.
Bilateral prophylactic mastectomy may:
Some women choose this option because it eases their worries about getting breast cancer. It may also make them feel they have done all they can do to lower their risk of breast cancer.
If you are a BRCA1/2 carrier, talk with your health care provider about the risks and benefits of all your risk-lowering options to make decisions that are right for you.
Learn more about prophylactic mastectomy.
Learn about breast reconstruction after mastectomy.
Prophylactic oophorectomy is the surgical removal of the ovaries to prevent ovarian cancer. It can lower the risk of ovarian cancer by 70 to over 90 percent [202,301,303-308].
The NCCN recommends women with BRCA1/2 mutations, have an oophorectomy between ages 35-40 (or after childbearing is complete) .
BRCA2 carriers tend to be diagnosed with ovarian cancer at a later age than BRCA1 carriers . So, BRCA2 carriers who have had bilateral prophylactic mastectomy may delay oophorectomy until age 40-45 .
Prophylactic oophorectomy may also lower the risk of breast cancer [202,309].
Some support groups are tailored to BRCA1 and BRCA2 carriers and people with BRCA1/2-related breast cancers.
Our Support section offers a list of resources to help find local and online support groups. For example, FORCE is an organization that has online support for women affected by hereditary breast and/or ovarian cancer.
Sharsheret has online support for Jewish women affected by hereditary breast and/or ovarian cancer.
BreastCancerTrials.org in collaboration with Susan G. Komen® offers a custom matching service to help you find clinical trials for people with a BRCA1/2 or other gene mutations.
Research Fast Facts
BRCA Genes and Breast Cancer
Hereditary Breast Cancer
Genetics and Breast Cancer
Questions to Ask Your Doctor: Inherited Genes and Breast Cancer Risk