BRCA1 and BRCA2 Inherited Gene Mutations in Women
BRCA1 and BRCA2 (BReast CAncer genes 1 and 2) are the most well-known genes linked to breast cancer.
This section provides information on BRCA1 and BRCA2 (BRCA1/2) inherited gene mutations in women. If you or a family member has a BRCA1/2 inherited gene mutation, you may have questions about what this means for you. Learn more about:
- Breast cancer risk
- Ovarian cancer risk
- Risk of other cancers
- Genetic testing
- Breast cancer screening recommendations
- BRCA1/2 mutations and risk factors for breast cancer
- Risk-lowering options
- Clinical trials
Learn about BRCA1/2 inherited gene mutations in men.
Genes and inherited gene mutations
What are genes?
Every cell in your body has 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 your mother and your father. And, you can pass this information on to your children (your daughters and your sons).
What are inherited 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.
Inherited gene mutations are also called germline mutations.
Inherited 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 a known inherited gene mutation [4,32].
Learn more about inherited gene mutations.
BRCA1 and BRCA2 inherited gene mutations
Everyone has BRCA1 and BRCA2 (BRCA1/2) genes. Some people have an inherited mutation in one or both of these genes that increases the risk of breast cancer.
BRCA1/2 inherited gene mutations can be passed to you from either parent. They increase the risk of cancers in both women and men.
A person who has a BRCA1/2 inherited gene mutation is sometimes called a BRCA1/2 carrier.
Proportion of people in the U.S. who have BRCA1 or BRCA2 inherited gene mutation
Like other inherited gene mutations, BRCA1/2 mutations are rare in the general population. In the U.S., about 1 in 400 people have a BRCA1/2 gene mutation .
The proportion of people who have a BRCA1/2 gene mutation varies by ethnic group. Among Ashkenazi Jewish women and men, about 1 in 40 have a BRCA1/2 gene mutation . Data on BRCA1/2 mutations in some ethnic groups are limited and more study is needed.
Percentage of women with breast cancer in the U.S. who have a BRCA1 or BRCA2 inherited gene mutation
The table below shows the prevalence of BRCA1/2 inherited gene mutations in women diagnosed with breast cancer, by ethnic group (in alphabetical order).
Percentage of U.S. women with breast cancer who have a BRCA1 or BRCA2 inherited gene mutation, by ethnic group (in alphabetical order)
Black and African American
Data not available
Less than 1%
Data not available
White (non-Ashkenazi Jewish)
Data not available
Adapted from National Cancer Institute materials and Malone et al. [32,205].
Breast cancer risk in women with BRCA1 and BRCA2 inherited gene mutations
Women who have a BRCA1 or BRCA2 (BRCA1/2) inherited gene mutation have an increased risk of breast cancer [32-38].
BRCA1/2 gene mutations are thought to explain a large portion of hereditary breast cancers .
Most breast cancers, however, are not related to inherited gene mutations.
A woman who has a BRCA1/2 inherited gene mutation may be called a BRCA1/2 carrier.
Estimates of breast cancer risk
Estimates of breast cancer risk are different for BRCA1 carriers and BRCA2 carriers. By age 70, the chance of developing breast cancer is [3,32,34-37]:
- 50-65 percent for women who have a BRCA1 inherited gene mutation
- 50-55 percent for women who have a BRCA2 inherited gene mutation
- 7 percent for women in the general population
This means by age 70:
- In a group of 100 women with a BRCA1/2 gene mutation, 50-65 will get breast cancer
- In a group of 100 women without a BRCA1/2 gene mutation, about 7 will get breast cancer
These numbers represent average risk. The risk of breast cancer for any one woman with a BRCA1/2 gene mutation may fall outside this range.
Note these risks are not 100 percent. Many women with a BRCA1/2 gene mutation will never have breast cancer [33-35]. A combination of factors likely causes breast cancer. So, some women with a BRCA1/2 mutation will get breast cancer and many will not.
Learn about risk-lowering options for women at higher risk.
Learn about genetic testing.
Triple negative breast cancer
Triple negative breast cancers are:
- Estrogen receptor-negative (ER-negative)
- Progesterone receptor-negative (PR-negative)
BRCA2 carriers tend to have breast cancers that are estrogen receptor-positive (ER-positive) [32,204,206].
Second primary breast cancer
BRCA1 and BRCA2 (BRCA1/2) inherited gene mutation can increase the risk of a second primary breast cancer (a second breast tumor not related to the first one) [32,207-211].
These tumors usually occur in the contralateral (opposite) breast rather than in the same breast as the first cancer.
The chance of a contralateral breast cancer 10 years after diagnosis of the first cancer is [32,207-211,298]:
- About 10-30 percent for women with a BRCA1/2 gene mutations
- About 5-10 percent for women without a BRCA1/2 gene mutation
The lifetime risk of a second primary contralateral breast cancer is about 40-80 percent for BRCA1/2 carriers [36,193,208,211].
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 [38,193]. This should be discussed with a health care provider.
For a summary of research studies on BRCA1/2 inherited gene mutations and breast cancer, visit the Breast Cancer Research Studies section.
Lowering the risk of breast cancer
Women who have a BRCA1/2 inherited gene mutation have options to lower their risk of breast cancer.
Ovarian cancer risk in women with a BRCA1 or BRCA2 inherited gene mutation
Women who have a BRCA1 or BRCA2 (BRCA1/2) inherited gene mutation may be called BRCA1/2 carriers. BRCA1/2 carriers have an increased risk of ovarian cancer [32,38].
The lifetime risk of ovarian cancer (up to age 70) is :
- 35-70 percent for women who have a BRCA1 gene mutation
- 10-30 percent for women who have a BRCA2 gene mutation
- Less than 2 percent for women in the general population
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’re diagnosed.
BRCA1/2 carriers who get ovarian cancer appear to have better survival than non-carriers in the first 5 years after diagnosis [213-214]. One reason for this improved survival may be that BRCA1/2-related ovarian cancers appear to respond better 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
Prophylactic oophorectomy may also lower the risk of breast cancer .
For a summary of research studies on BRCA1/2 inherited gene mutations and ovarian cancer, visit the Breast Cancer Research Studies section.
Risk of other cancers in women with a BRCA1 or BRCA2 inherited gene mutation
Women who have a BRCA1 or BRCA2 (BRCA1/2) inherited gene mutation have an increased risk of pancreatic cancer [32,38].
The National Comprehensive Cancer Network (NCCN) doesn’t recommend pancreatic cancer screening for all women with a BRCA1/2 gene mutation . However, the NCCN recommends some women who also have a close family member with pancreatic cancer consider pancreatic cancer screening .
Women who have a BRCA2 inherited gene mutation (BRCA2 carriers) have an increased risk of melanoma [32,38].
The NCCN does not have melanoma screening guidelines for BRCA2 carriers. However, it recommends BRCA2 carriers limit sun exposure and consider yearly full-body skin exams to check for signs of melanoma .
BRCA1/2 gene 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 inherited gene mutations and cancer, visit the Breast Cancer Research Studies section.
Prognosis (chances for survival) for BRCA1– or BRCA2-related breast cancers
For women with breast cancer, prognosis is similar for those who have a BRCA1 or BRCA2 (BRCA1/2) inherited gene mutation and for those who don’t have a BRCA1/2 gene mutation [217-219].
Treatment for BRCA1– and BRCA2-related breast cancers
In general, breast cancers related to a BRCA1 or BRCA2 (BRCA1/2 ) inherited gene mutation are treated in the same way breast cancers not related to a BRCA1/2 gene mutation are treated.
However, some drug therapies may be more effective in treating BRCA1/2-related breast cancers than other breast cancer .
Early breast cancer treatment
The PARP inhibitor olaparib (Lynparza) is used to treat some HER2-negative early breast cancers in people who have a BRCA1/2 inherited gene mutation .
Learn more about olaparib in the treatment of early breast cancer.
Learn more about emerging areas in drug therapies for early breast cancer.
Metastatic breast cancer treatment
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 and cisplatin) are preferred chemotherapy drugs for the treatment of BRCA1/2-related metastatic breast cancers [220,222].
Learn more about treatments for metastatic breast cancer.
Genetic testing for BRCA1 and BRCA2 inherited gene mutations
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 (BRCA1/2) inherited gene mutation.
Who should consider genetic testing for BRCA1 and BRCA2 inherited gene mutations?
Genetic testing is only recommended for people with a high risk of having a BRCA1/2 inherited gene mutation (or other high-risk inherited gene mutation related to breast cancer), including those with :
- A family member with a BRCA1/2 inherited gene mutation (or other inherited gene mutation related to breast cancer)
- A personal history of breast cancer at age 45 or younger
- A personal history of triple negative breast cancer (breast cancer that is estrogen receptor-negative, progesterone receptor-negative and HER2-negative) diagnosed at any age
- A personal history of lobular breast cancer at any age, and a personal or family history of diffuse gastric cancer
- 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 age 51 or older and a close family member diagnosed with breast cancer at age 50 or younger
- A personal history of breast cancer at age 51 or older and 2 or more close family members diagnosed with breast cancer or prostate cancer at any age
- A close family member diagnosed with breast cancer at age 45 or younger
- A close family member diagnosed with ovarian cancer, pancreatic cancer or metastatic prostate cancer at any age
- A personal or family history of male breast cancer
In most cases, testing for BRCA1/2 inherited gene mutations is first done on the person with breast, ovarian, pancreatic or prostate cancer.
- If no mutation is found, the cancer was not due to a BRCA1/2 gene mutation.
- If a BRCA1/2 gene mutation is found, other family members (women and men) can be tested for the specific mutation.
Just because one person in a family has an inherited gene mutation doesn’t mean everyone in the family has the gene 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’ll 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 for high-risk inherited gene mutations related to breast cancer
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 inherited gene mutation only requires a blood or saliva sample, but there are risks and benefits to consider 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
Breast cancer screening tests are used to find cancer in a person who has no warning signs or symptoms.
Women who have a BRCA1 or BRCA2 (BRCA1/2) inherited gene mutation 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.
Every 6-12 months
Only if breast MRI is not available:
Every 6-12 months
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.
BRCA1 and BRCA2 inherited gene mutations and risk factors for breast cancer
Women who have a BRCA1 or BRCA2 (BRCA1/2) inherited gene mutation may be called BRCA1/2 carriers. Most risk factors for breast cancer in women likely impact risk the same way for women who are BRCA1/2 carriers and those who are non-carriers.
However, breast cancer risk for BRCA1/2 carriers with certain reproductive and lifestyle factors may be different from risk for non-carriers.
- Having children and a younger age at first childbirth are linked to a lower risk of breast cancer in the general population. In BRCA1/2 carriers however, some studies show no link between these factors and breast cancer risk [222,225-228].
- Drinking alcohol and current or recent use of birth control pills are linked to an increased risk of breast cancer in the general population. It’s unclear whether these factors are linked to risk in BRCA1/2 carriers [222,225-226,229-230].
People exposed to very low doses of radiation (such as from X-rays) don’t have much, if any, increased risk of breast cancer [231-232].
However, there’s some concern the radiation exposure from screening mammograms at younger ages may be linked to a higher risk of breast cancer in BRCA1/2 carriers than in other women . This issue is under study.
Breast MRI doesn’t use radiation. The NCCN recommends women ages 25-29 who have a BRCA1/2 inherited gene mutation get breast cancer screening with a breast MRI every year . Mammography isn’t recommended for these young women unless breast MRI isn’t available .
Women who have a BRCA1 or BRCA2 (BRCA1 /2) inherited gene mutation have medical options to help lower their risk of breast cancer:
If you have a BRCA1/2 inherited gene mutation, 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.
Tamoxifen and raloxifene are FDA-approved for breast cancer risk reduction in women at high risk, including women with BRCA1/2 inherited gene mutations. Both tamoxifen and raloxifene are pills.
Both tamoxifen and raloxifene can lower the risk of :
- Invasive breast cancer
- Non-invasive breast cancer, such as ductal carcinoma in situ (DCIS)
Both premenopausal women 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. Both drugs can cause menopausal symptoms such as hot flashes.
Learn more about the side effects of tamoxifen and raloxifene.
Learn about treating menopausal symptoms.
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.
Aromatase inhibitors are hormone therapy drugs used to treat estrogen receptor-positive breast cancer. Aromatase inhibitors are pills.
Exemestane and anastrozole are aromatase inhibitor drugs. Findings from randomized controlled trials have shown exemestane and anastrozole may lower the risk of developing breast cancer in postmenopausal women at higher risk [235-236].
The American Society for Clinical Oncology (ASCO), the National Comprehensive Cancer Network (NCCN) and the U.S. Preventive Services Task Force list exemestane and anastrozole as risk-lowering drug options for postmenopausal women who do not have breast cancer, but are at higher risk of breast cancer.
However, these drugs do not have FDA-approval for use in the risk reduction setting. They’re only FDA-approved for use in breast cancer treatment.
Learn about aromatase inhibitors and breast cancer treatment.
Learn more about risk-lowering drugs.
Preventive surgery — prophylactic mastectomy and prophylactic oophorectomy
Bilateral prophylactic mastectomy is the removal of both breasts to prevent breast cancer.
Bilateral prophylactic mastectomy may:
- Lower the risk of breast cancer by 90 percent or more in women who have a BRCA1/2 inherited gene mutation (BRCA1/2 carriers) [38,237-240]
- Add 3-5 years to the lifespan of a 30-year old woman who is a BRCA1/2 carrier [241-242]
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 pros and cons 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 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 [38,241,243-247].
The NCCN recommends women with a BRCA1/2 inherited gene mutation (BRCA1/2 carriers), have an oophorectomy between ages 35-40 (or after childbearing is complete) to lower their risk of ovarian cancer .
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 in BRCA1/2 carriers .
For premenopausal women, prophylactic oophorectomy leads to early menopause.
Learn more about early menopause and how to manage its symptoms.
Some support groups are tailored to people who have a BRCA1 or BRCA2 (BRCA1/2) inherited gene mutations and people who have BRCA1/2-related breast cancers.
For example, FORCE is an organization that provides online and telephone support and a resource guide for individuals and caregivers affected by hereditary breast, ovarian and other cancers.
Sharsheret offers online support for Jewish women affected by hereditary breast and/or ovarian cancer.
SUSAN G. KOMEN® SUPPORT RESOURCES
The NCCN encourages people with a BRCA1 or BRCA2 (BRCA1/2) inherited gene mutation to consider participating in clinical trials of cancer screening or imaging.
Susan G. Komen® Breast Care Helpline
If you or a loved one needs information or resources about clinical trials, call the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877- 465- 6636) or email email@example.com.
Se habla español.
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 clinical trials on breast cancer treatment for people who have a BRCA1/2 inherited gene mutation.
You can also visit the National Institutes of Health’s website to find clinical trials.
Learn more about clinical trials.
Insurance issues and financial assistance
If you have insurance issues (such as a claim is denied) or need help paying for genetic testing, risk-lowering drugs or other out-of-pocket expenses, there are resources that may help.
Komen Financial Assistance Program
Susan G. Komen® offers the Komen Financial Assistance Program to eligible individuals undergoing breast cancer treatment at any stage or living with metastatic breast cancer (stage IV).
Financial assistance is granted to those who meet pre-determined eligibility criteria.
To learn more about this program and other helpful resources, call the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877-465-6636) or email firstname.lastname@example.org.
Se habla español.
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