The Who, What, Where, When and Sometimes, Why.

BRCA1 and BRCA2

BRCA1 and BRCA2 (BReast CAncer genes 1 and 2) are the most well-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 BRCA1/2 genetic testing and other topics.

Learn about BRCA1/2 gene mutations in women.

Learn about BRCA1/2 gene mutations in men.

Genes and gene mutations

Genes

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).

Gene mutations

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, for example, if your mother has a BRCA1 gene mutation, there’s a 50 percent chance you will also have a BRCA1 mutation.

Gene mutations and health

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 [4,28]. 

Learn more about inherited gene mutations.

BRCA1 and BRCA2 (BRCA1/2) 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.

Prevalence of BRCA1/2 gene mutations in the U.S.

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 [28].

Prevalence varies by ethnic group. Among Ashkenazi Jewish women and men, about 1 in 40 have a BRCA1/2 mutation [28].

Prevalence of BRCA1/2 gene mutations among U.S. women with breast cancer

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)

 

BRCA1

 BRCA2

African-American

1%

3%

Ashkenazi Jewish

8-10%

Data not available

Asian-American

Less than 1%

Data not available

White (non-Ashkenazi Jewish)

2-3%

2%

Hispanic

4%

Data not available

Adapted from National Cancer Institute materials and Malone et al. [28,180]. 

 

Read our blog about breast cancer in men.

BRCA1/2 mutations and cancer risks

Men can have BRCA1 and BRCA2 gene mutations and can pass them on to their children.

Increased risk of breast cancer

Men who have a BRCA2 mutation, and to a lesser degree men who have a BRCA1 mutation, have an increased risk of breast cancer [28-29,31,35,147,191].

For example, the lifetime risk of breast cancer (up to age 80) is [147,190,193-194]:

  • 50-80 in 1,000 men with a BRCA2 mutation
  • About 12 in 1,000 men with a BRCA1 mutation
  • About 1 in 769 men (up to any age) in the general population

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 alone [195].

This means men who get breast cancer are more likely to have an inherited gene mutation than women who get breast cancer. The National Comprehensive Cancer Network (NCCN) recommends all men diagnosed with breast cancer have genetic testing for BRCA1/2 mutations [147].

Learn more about breast cancer in men.

Learn about breast cancer screening for men with a BRCA1/2 gene mutation.

 

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Komen Perspectives

Read our perspective on breast cancer in men.*

 

Increased risk of prostate cancer

Men who have a BRCA1/2 mutation have an increased risk of prostate cancer [28,31,190,193,196-197].

The lifetime risk of prostate cancer is [193,197]:

  • 7-25 percent for men with a BRCA1 mutation
  • 20-60 percent for men with a BRCA2 mutation 
  • 12 percent for men in the general population

Learn about prostate cancer screening for men with a BRCA1/2 gene mutation.

Other types of cancer

BRCA1/2 carriers also have an increased risk of pancreatic cancer and melanoma (BRCA2 carriers) [28,32,147]. They also increase the risk of a second primary breast cancer in the opposite (contralateral) breast [28,147]. These are new breast cancers that develop after a first breast cancer.

BRCA1/2 mutations may also increase the risk of other cancers [28]. However, data are limited and these topics are still under study.

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For a summary of research studies on BRCA1/2 mutations and breast cancer, visit the Breast Cancer Research Studies section.

 

Genetic testing

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 [147].

Learn more about genetic testing.

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Komen Perspectives

Read our perspective on genetic testing.*

 

Cancer screening recommendations

Cancer screening tests are used to find cancer in a person who has no warning signs or symptoms.

The NCCN has breast cancer and prostate cancer screening recommendations for men who are BRCA1/2 carriers.

Breast cancer screening

The NCCN recommends, starting at age 35 [147]:

Men with a BRCA1/2 gene mutation should also be aware of the warning signs of breast cancer.

Prostate cancer screening

The NCCN recommends, starting at age 40 [147]:

  • Men with a BRCA2 gene mutation have prostate cancer screening 
  • Men with a BRCA1 gene mutation consider having prostate cancer screening

Melanoma screening

The NCCN does not have melanoma screening guidelines for men with a BRCA2 gene mutation. However, it does recommend they consider yearly full-body skin exams to check for signs of melanoma and limiting sun exposure [147].

Risk factors for breast cancer in men with BRCA1/2 mutations

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.

Support

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

  • If you or a loved one needs more information about breast health or breast cancer, call the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877-465-6636). All calls are answered by a trained specialist or oncology social worker in English and Spanish, Monday through Friday from 9:00 a.m. to 10:00 p.m. ET. You can also email the helpline at helpline@komen.org
  • We offer an online support community through our closed Facebook Group – Komen Breast Cancer group. The Facebook group provides a place where those with a connection to breast cancer can discuss each other’s experiences and build strong relationships to provide support to each other. Visit Facebook and search for “Komen Breast Cancer group” to request to join the closed group.
  • Our free, 6-week telephone support groups for men with breast cancer provide a safe place for men to discuss the challenges of breast cancer, get information and exchange support. To learn more, call the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877-465-6636) or email helpline@komen.org.
  • Komen Affiliates offer breast health education as well as fund breast cancer programs through local community organizations. Your local Affiliate may also help you find breast cancer resources in your area. Find your local Affiliate.
  • Our fact sheets, booklets and other education materials offer additional information.

 

Clinical trials

Susan G. Komen® Breast Cancer Clinical Trial Information Helpline
If you or a loved one needs information or resources about clinical trials, call our Clinical Trial Information Helpline at 1-877 GO KOMEN (1-877- 465- 6636) or email clinicaltrialinfo@komen.org.

BreastCancerTrials.org in collaboration with Susan G. Komen® offers a custom matching service to help find clinical trials on risk reduction. BreastCancerTrials.org can also help find breast cancer treatment clinical trials for people who have a BRCA1/2 gene mutation.

You can also visit the National Institutes of Health’s website to find clinical trials.  

Learn more about clinical trials.  

 

BRCA1 and BRCA2 mutations in women

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:

Breast cancer risk in women with a BRCA1/2 mutation

Women who have a BRCA1 or BRCA2 gene mutation have an increased risk of breast cancer [29-31].

Estimates of risk are different for BRCA1 carriers and BRCA2 carriers. By age 70, the chance of developing breast cancer is [28,30-31]:

  • 55-65 percent for BRCA1 carriers
  • 45-55 percent for BRCA2 carriers

Women in the general population have about a 7 percent chance of getting breast cancer by age 70 [3]. (The lifetime risk of breast cancer is about 12 percent [3].)

This means by age 70:

  • In a group of 100 women without a BRCA1/2 mutation, about 7 will get breast cancer
  • In a group of 100 women with a BRCA1/2 mutation, 45-65 will get breast cancer

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 [29-31]. A combination of factors likely causes breast cancer.

BRCA1/2 mutations are thought to explain a large portion of hereditary breast cancers [28].

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.

Triple negative breast cancer

Women who have a BRCA1 mutation have an increased risk of triple negative breast cancer (meaning they tend to get breast cancers that are triple negative) [28,182-183].

Triple negative breast cancers are:

BRCA2 carriers tend to have breast cancers that are estrogen receptor-positive (ER-positive) [28,182-183].

Learn about hormone (estrogen and progesterone) receptor status, HER2 status and other factors that affect prognosis and treatment.

Second primary breast cancer

A BRCA1/2 mutation can increase the risk of a second primary breast cancer (a second breast tumor not related to the first one) [28,184-189].

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 [32,184-189].

The lifetime risk of a second primary contralateral breast cancer is about 40-80 percent for BRCA1/2 carriers [32,181,186,189].

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 [147,179]. This should be discussed with a health care provider.

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For a summary of research studies on BRCA1/2 mutations and breast cancer, visit the Breast Cancer Research Studies section.

Lowering the risk of breast cancer

There are options for women with BRCA1/2 gene mutations to lower their risk of breast cancer

Ovarian cancer risk in women with a BRCA1/2 mutation

BRCA1/2 mutations increase a woman’s risk of ovarian cancer [28].

The lifetime risk of ovarian cancer (up to age 70) is [198]:

  • Less than 2 percent for women in the general population
  • 35-70 percent for women with a BRCA1 mutation
  • 10-30 percent for women with a BRCA2 mutation

Ovarian cancer survival

Although BRCA1/2 carriers have a higher risk of ovarian cancer than non-carriers, this doesn’t 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 [214]. 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 [215-216].

Long-term data on survival in BRCA1/2 carriers diagnosed with ovarian cancer are limited.

Lowering the risk of ovarian cancer

BRCA1/2 carriers can reduce their risk of ovarian cancer by having prophylactic oophorectomy (surgical removal of the ovaries) [179].

Prophylactic oophorectomy may also lower the risk of breast cancer [179].

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For a summary of research studies on BRCA1/2 mutations and ovarian cancer, visit the Breast Cancer Research Studies section

Risk of other cancers in women with a BRCA1/2 mutation

Pancreatic cancer

Women with a BRCA1/2 gene mutation have an increased risk of pancreatic cancer [28,147].

There are no pancreatic cancer screening guidelines for people with BRCA1/2 mutations.

Melanoma

Women with a BRCA2 gene mutation have an increased risk of melanoma [28,147].

Although the NCCN does not have melanoma screening guidelines for people with a BRCA2 mutation, it does recommend they consider yearly full-body skin exams to check for signs of melanoma and limiting sun exposure [147].

Other cancers

BRCA1/2 mutations may also increase the risk of other cancers [28]. However, data are limited and these topics are still under study.

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For a summary of research studies on BRCA1/2 mutations and cancer, visit the Breast Cancer Research Studies section.

Prognosis for BRCA1/2-related breast cancer

With treatment, women with a BRCA1 or BRCA2 mutations appear to have similar breast cancer survival as women without BRCA1/2 mutations [217-218].

Treatment for BRCA1/2-related breast cancer

In general, breast cancers related to BRCA1 and BRCA2 mutations are treated in the same way 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 [219].

The PARP inhibitors olaparib (Lynparza) and talazoparib (Talzenna) are used to treat metastatic breast cancers in some people who have BRCA1/2 gene mutations. These drugs are not used to treat breast cancers in people who don’t have BRCA1/2 gene mutations.

Platinum-based chemotherapy drugs (such as carboplatin) may be better at treating BRCA1/2-related breast cancers than other breast cancers [220-222]. 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

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 don’t have a BRCA1 or BRCA2 gene mutation.

Who should consider BRCA1/2 genetic testing?

BRCA1/2 is only recommended for people with a high risk of having a BRCA1/2 gene mutation, including those with [147]:

  • A family member with a BRCA1/2 gene mutation (or other inherited gene mutation linked to breast cancer)
  • A personal history of breast cancer at age 45 or younger
  • A personal history of bilateral breast cancer (cancer in both breasts)
  • A personal history of triple negative breast cancer (breast cancer that is estrogen receptor-negative, progesterone receptor-negative and HER2-negative) diagnosed at age 60 or younger
  • Ashkenazi Jewish heritage and a personal history of breast cancer
  • A personal history of breast cancer at age 46-50 and a close family member (parent, sibling, child, grandparent, grandchild, uncle, aunt, nephew, niece or first cousin) diagnosed with breast cancer at any age
  • A personal history of breast cancer at any age and a close family member diagnosed with breast cancer at age 50 or younger
  • A personal history of breast cancer at any age and 2 or more close family members diagnosed with breast cancer at any age
  • A personal history of breast cancer at any age and a close family member diagnosed with pancreatic cancer, aggressive prostate cancer or metastatic prostate cancer at any age
  • A family member (parent, sibling, child, grandparent, grandchild, uncle, aunt, nephew or niece) diagnosed with breast cancer at age 45 or younger
  • A personal or family history of ovarian cancer, pancreatic cancer, aggressive prostate cancer or metastatic prostate cancer
  • A personal or family history of male breast cancer

In most cases, testing is first done on the person with breast, ovarian, pancreatic or aggressive prostate cancer.

  • If no mutation is found, the cancer was not due to a BRCA1/2 mutation.
  • If a BRCA1/2 mutation is found, other family members can be tested for the specific mutation.

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).

Weighing the risks and benefits of genetic testing

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.

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Komen Perspectives

Read our perspective on genetic testing.*

Breast cancer screening

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 [147]:

 

Clinical breast exam

Mammogram

Breast MRI

Under age 25

Every 6-12 months

Not recommended

Not recommended

Ages 25-29

Every 6-12 months

Only if breast MRI is not available: Every year

Every year (if breast MRI is not available, mammogram)

Ages 30 and older

Every 6-12 months

Every year

Every year

Learn more about breast cancer screening recommendations for women at higher risk.

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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

BRCA1/2 mutations and risk factors for breast cancer

Most risk factors for breast cancer in women likely impact risk in the same way in BRCA1 and BRCA2 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 [199-200].

However, certain reproductive and lifestyle factors may affect risk in BRCA1/2 carriers differently than in non-carriers.

For example:

Radiation exposure

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 [206-207].

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 [208].

This issue is under study. 

Risk-lowering options

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.

Risk-lowering drugs: tamoxifen and raloxifene

For women at high risk of breast cancer, tamoxifen and raloxifene can lower the risk of [223]:

Tamoxifen and raloxifene only reduce the risk of estrogen receptor-positive breast cancers. Neither drug reduces the risk of estrogen receptor-negative cancers [223]. 

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 [223]. This makes raloxifene a better choice for some women.

Learn more about the side effects of tamoxifen and raloxifene.  

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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.

Preventive surgery — prophylactic mastectomy and prophylactic oophorectomy 

Prophylactic mastectomy

Bilateral prophylactic mastectomy is the removal of both breasts to prevent breast cancer.

Bilateral prophylactic mastectomy may:

  • Lower the risk of breast cancer by at least 90 percent in women who are BRCA1/2 carriers [147,224-227]
  • Add 3-5 years to the lifespan of a 30-year old woman who is a BRCA1/2 carrier [228-229]

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 each risk-lowering option and make the decision that’s right for you.

Learn more about prophylactic mastectomy.

Learn about breast reconstruction after mastectomy.

Prophylactic oophorectomy

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 [147,228,230-235].

The NCCN recommends women with BRCA1/2 mutations, have an oophorectomy between ages 35-40 (or after childbearing is complete) [147].

BRCA2 carriers tend to be diagnosed with ovarian cancer at a later age than BRCA1 carriers [147]. So, BRCA2 carriers who have had bilateral prophylactic mastectomy may delay oophorectomy until age 40-45 [147].

Prophylactic oophorectomy may also lower the risk of breast cancer [147,236]. 

Support

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 offers online support for people at higher risk of breast, ovarian or other cancers related to family history or inherited gene mutations.

Sharsheret offers online support for Jewish women affected by hereditary breast and/or ovarian cancer.

SUSAN G. KOMEN® SUPPORT RESOURCES

  • If you or a loved one needs more information about breast health or breast cancer, call the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877-465-6636). All calls are answered by a trained specialist or oncology social worker in English and Spanish, Monday through Friday from 9:00 a.m. to 10:00 p.m. ET. You can also email the helpline at helpline@komen.org
  • We offer an online support community through our closed Facebook Group – Komen Breast Cancer group. The Facebook group provides a place where those with a connection to breast cancer can discuss each other’s experiences and build strong relationships to provide support to each other. Visit Facebook and search for “Komen Breast Cancer group” to request to join the closed group.
  • Komen Affiliates offer breast health education as well as fund breast cancer programs through local community organizations. Your local Affiliate may also help you find breast cancer resources in your area. Find your local Affiliate
  • Our fact sheets, booklets and other education materials offer additional information. 

 

Clinical trials

Susan G. Komen® Breast Cancer Clinical Trial Information Helpline
If you or a loved one needs information or resources about clinical trials, call our Clinical Trial Information Helpline at 1-877 GO KOMEN (1-877- 465- 6636) or email clinicaltrialinfo@komen.org.

BreastCancerTrials.org in collaboration with Susan G. Komen® offers a custom matching service to help find clinical trials on risk reduction. BreastCancerTrials.org can also help find breast cancer treatment clinical trials for people who have a BRCA1/2 gene mutation.

You can also visit the National Institutes of Health’s website to find clinical trials.

Learn more about clinical trials.