What are BRCA1 and BRCA2?

Your body is made up of tiny building blocks called cells. Inside every cell is a set of genes. These genes are the instructions the cell needs to work properly. BRCA1 and BRCA2 are two genes that everyone has.

BRCA gene mutations and cancer

Sometimes the structure inside a gene is permanently changed. This means the gene no longer gives the correct instructions. This change is called a gene mutation.

The BRCA1 and BRCA2 genes normally protect us from breast and ovarian cancer. A mutation in one of these genes means that protection is lost. Over time, this may mean cancers are more likely to develop.

The risk is highest for breast cancer in women. But it is also higher than average for:

We have more information about gene mutations and how cancer develops.

How BRCA mutations run in families

Genes are passed from parent to child (inherited) when a sperm and egg join to start a pregnancy (conception).

A woman who inherits a BRCA1 or BRCA2 mutation:

  • has a high risk of breast and ovarian cancer
  • has a 1 in 2 (50%) chance of passing the mutation on to each of her children.

A man who inherits a BRCA1 or BRCA2 mutation:

  • may have a small increase in his risk of developing breast cancer (this is mainly if he has the BRCA2 mutation)
  • may have a higher risk of prostate or pancreatic cancer (mainly BRCA2)
  • has a 1 in 2 (50%) chance of passing the mutation on to each of his children.

If you do not inherit a BRCA1 or BRCA2 mutation, you cannot pass it on to any of your children.

Understanding your family history of cancer

Not everyone with a BRCA1 or BRCA2 mutation has a family history of cancer. But in general, a gene mutation is more likely if there is a pattern of cancer in a family. These are examples of patterns:

  • One of your first-degree relatives was diagnosed with breast cancer before the age of 40. (First-degree relatives are your parents, brothers, sisters and children.)
  • Several family members have been diagnosed with breast cancer or ovarian cancer.
  • A male relative was diagnosed with breast cancer.
  • A relative had breast cancer in both breasts (bilateral breast cancer).
  • You have a family history of cancer and you are from an Eastern European or Ashkenazi Jewish (Eastern European Jewish) background. Some types of BRCA mutations are more common in these ethnic groups.

If you are worried about the pattern of cancer in your family, talk to your GP. They may be able to reassure you, or refer you to a genetics specialist.

If you meet a genetics specialist, they will talk to you about your family’s history of cancer. They will explain if you are likely to have a higher risk because of the pattern of cancer in your family. If they think you may carry a BRCA1 or BRCA2 mutation, you may be offered a blood test to have genetic testing.

Genetic testing for a BRCA mutation

A BRCA1 or BRCA2 mutation may be found by a genetic blood test. You may be offered this test if you have:

  • breast cancer at an unusually young age
  • certain types of breast cancer, such as triple-negative breast cancer, at a young age
  • certain types of ovarian cancer, such as high-grade serous ovarian cancer
  • a strong family history of cancer that suggests a BRCA1 or BRCA2 mutation may be present
  • a relative who has a BRCA1 or BRCA2 mutation.

Understanding genetic test results

If genetic testing shows you have a BRCA1 or BRCA2 mutation, this does not mean you will definitely get cancer. You may have a higher risk of some types of cancer.

Your risk of cancer will depend on:

  • whether you are male or female
  • your age
  • the exact gene mutation
  • your family history.

Your genetics specialist will explain this in detail. We have more information about:

Sometimes genetic testing does not find a BRCA1 or BRCA2 mutation. You may still have a higher risk of cancer because of the pattern of cancer in your family. Your genetics specialist will explain if you can have genetic testing for other types of mutation. You and your family may still be offered extra screening or treatment to reduce your risk of cancer.

Screening if you have a BRCA mutation

Screening uses tests to:

  • find cancer at an early stage, when it can be treated most effectively
  • find and treat changes that are likely to develop into cancer.

Depending on your cancer risk, your genetics specialist will explain:

  • which screening tests are useful for you
  • when these tests should start
  • how often you will need these tests.

Breast screening

Women with BRCA1 or BRCA2 mutations are offered tests to look for early signs of breast cancer. The tests offered depend on your age. We have more information about breast screening for women with a higher risk of breast cancer.

Screening for other cancers

People with a BRCA1 or BRCA2 mutation are not usually offered screening for other cancers. This is because:

  • the risk of other cancer types linked to BRCA1 or BRCA2 mutations is usually much lower than for breast cancer in women
  • regular screening tests cannot prevent these cancers
  • there is no clear evidence that screening tests for these cancers are good at finding cancer early when it is more treatable.

Sometimes screening for other cancer types is offered as part of a research trial. Taking part in a research trial is completely up to you. Your doctor or nurse can explain the possible risks and benefits of taking part.

Prostate test

Even though there is no screening programme, men with a BRCA1 or BRCA2 mutation sometimes have a blood test called the PSA test. This test can help to diagnose early prostate cancer. Before you have the test, your GP or nurse will talk with you about the benefits and disadvantages of having it.

Risk-reducing treatments and BRCA

Women with a BRCA1 or BRCA2 mutation may decide to have treatments to reduce their risk of breast and ovarian cancer. This may involve:

  • surgery to remove the breasts (called risk-reducing breast surgery).
  • surgery to remove the ovaries and fallopian tubes (called risk-reducing bilateral salpingo-oophorectomy).
  • drug treatment for a number of years (called risk reducing drugs).

We have more about these treatments in our information about inherited breast and ovarian cancer. If you are thinking about this type of treatment, your genetics specialist can give you more information. You may have questions about the best age for you to have surgery or how it may affect you. Sometimes it helps to talk to other people in the same situation. We have more information about getting support at the end of this page.

All treatments have risks and possible side effects. It is helpful to talk with your doctor about the benefits and disadvantages. You may also want to talk with your family and other people close to you before making your decision.

Symptoms and lifestyle

Cancer can often be successfully treated, especially when it is found at an early stage. Knowing what is normal for your body means you are more likely to recognise any changes that could be a sign of cancer. This means if you do develop a cancer, it can be treated as early as possible.

We have more information about possible symptoms of:

We also have general information about the signs and symptoms of cancer that you may find helpful. Symptoms can be caused by things other than cancer. But always see your doctor if you have symptoms that are ongoing or unusual for you.

There may also be factors in your lifestyle that affect your cancer risk. There is not always clear evidence about how such lifestyle factors affect cancer risk in people with a BRCA1 or BRCA2 mutation. But there is strong evidence that healthy lifestyle factors can improve your general health and well-being. Ask your genetics specialist for advice about your risks. Your healthcare team can give you more information about healthy living. 

Planning a family

If you have a BRCA1 or BRCA2 mutation, there is a 1 in 2 (50%) chance that any child you have could inherit it from you. You may have questions about this if you are planning to get pregnant or start a pregnancy. Your genetics specialist can talk to you about this if you have questions. We have more information about planning a family and inherited cancer risk.

Your feelings

Not everyone with a BRCA1 or BRCA2 mutation develops cancer. But it can be difficult to cope with the uncertainty of a higher cancer risk.

You may have questions about your family history, genetic testing, screening or whether you should have risk-reducing treatment. There may not always be clear answers. It is important to talk to your genetics specialist, GP or nurse. They will be happy to answer any questions you have.

There is no right or wrong way to cope, but help is there if you need it. If you are struggling to cope with a higher risk of cancer, talking about your feelings and worries may help. You may want to talk to a partner, family member or friend.

Macmillan is also here to support you. If you would like to talk, you can do the following: