BRCA1 and BRCA2 mutations

BRCA1 and BRCA2 are two genes everyone has. A mutation in one of these genes may cause a higher risk of breast, ovarian and some other types of cancer.

You may be offered a blood test to look for this type of mutation if you have:

  • breast cancer at an unusually young age
  • certain types of breast cancer
  • certain types of ovarian cancer
  • certain patterns of cancer in your family
  • a relative who has a BRCA1 or BRCA2 mutation.

You may have screening tests to help find and treat cancer at an early stage. Always see your GP or specialist if you have symptoms that are ongoing or unusual for you.

Women with a mutation may have treatment to reduce their risk of breast or ovarian cancer, such as:

  • surgery to remove the breasts, or ovaries and fallopian tubes
  • taking daily anti-oestrogen tablets for 5 years.

Your specialist will explain any risks or side effects of these, so you can make a decision about your treatment. They can also give you information about:

  • planning a family
  • having a healthy lifestyle.

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.

BRCA1 and BRCA2 mutations and cancer

Sometimes the structure inside a gene is permanently changed, so 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 the 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 BRCA1 and BRCA2 mutations run in families

Genes are passed from parent to child (inherited) when a sperm and egg join to start a pregnancy (conception). We have two copies of each gene – one from our mother and the other from our father. The sperm contains one copy of the father’s genes. The egg contains one copy of the mother’s genes.

If one parent has a BRCA1 or BRCA2 gene mutation, either the child will get the copy containing it, or they will not. There is a 1 in 2 (50%) chance the mutation is passed on.

How genes are passed on
How genes are passed on

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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. Your cancer risks are no higher than another person in the general population.

Gene mutations cannot ‘skip’ a generation in a family. But it can often seem like a BRCA1 or BRCA2 mutation has missed a generation. This is usually because a person in the family has the mutation and passes it to their child. But they do not develop cancer themselves.

For example, a man with the gene mutation is much less likely to develop cancer, because the cancer risks are generally lower for men than women with BRCA1 or BRCA2 mutations. If he has a daughter and she inherits the mutation from him, her cancer risks are much higher. If the man does not develop cancer but the daughter does, it can look like the mutation has skipped a generation.

Not all women with a BRCA1 or BRCA2 mutation develop cancer. If a mother passes the mutation to her child but does not develop cancer herself, it can also seem like the mutation has missed a generation.

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 check (genetic testing).

Genetic testing for a BRCA1 or BRCA2 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 cancer risk for:

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 BRCA1 or BRCA2 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:

  • If you are 30 to 39 – an MRI scan, and sometimes also a mammogram once a year.
  • If you are 40 to 49 – an MRI scan and a mammogram once a year.
  • If you are 50 to 69 – a mammogram once a year, and an MRI scan if you have dense breast tissue that makes a mammogram less clear.
  • If you are 70 or over – a mammogram every 3 years.

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 tests

Even though there is no screening programme, men with a BRCA1 or BRCA2 mutation sometimes have a blood test called the PSA test. This checks for prostate problems, and one of the problems may be cancer. Before you have the test, your GP or nurse will talk with you about the benefits and disadvantages of having it.

If you are having the PSA test, you usually have a rectal examination as well. This is when the doctor or nurse inserts a lubricated, gloved finger into your back passage (rectum) to feel the prostate. It is sometimes called a digital rectal examination. It may be uncomfortable, but it is quick and should not be painful. If there is cancer in the prostate, it can feel different. Normally the prostate feels smooth, but if there is a cancer, it can feel hard, rough or bumpy.

Risk-reducing surgery and BRCA1 or BRCA2

Women with a BRCA1 or BRCA2 mutation may decide to have surgery to reduce their risk of 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 surgery has 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.

Risk-reducing breast surgery

Removing both breasts reduces the risk of getting breast cancer by about 95%. Almost all the breast tissue is removed, but a very small amount will remain, so there is still a small risk of developing breast cancer.

Most women have new breast shapes made (reconstruction) at the same time as having risk-reducing breast surgery. But some women choose not to. New breast shapes can be made using tissue from another part of your body or with breast implants.

Risk-reducing removal of the ovaries

Removing both ovaries and fallopian tubes reduces the risk of cancer in and near the ovaries by over 95%. There is still a very small risk of a similar cancer developing in a nearby layer of tissue in the tummy called the peritoneum.

Women who decide to have this surgery will start the menopause if they have not already. They will no longer be able to get pregnant naturally. Your genetics specialist or GP can give you more information about this. You may think about starting your family earlier than you had planned or have questions about ways of preserving your fertility. You can ask to see a fertility specialist for further advice.

Risk-reducing drugs and BRCA1 or BRCA2

Women with a BRCA1 or BRCA2 mutation may choose to take anti-oestrogen drugs to reduce the risk of breast cancer if they:

  • have not had risk-reducing breast surgery
  • have not had breast cancer.

This involves taking a tablet every day for 5 years. The drugs are not suitable for everyone. It is important to talk to your doctor about the side effects, risks and benefits of any treatment you are offered.

The drug you take depends on whether you have been through the menopause and any other medical conditions you have. Women who have not had the menopause are usually offered a drug called tamoxifen. Women who have been through the menopause may be offered anastrozole or raloxifene.

If you have not had your menopause and are taking tamoxifen, you should use contraception to prevent pregnancy. This is because the drug may be harmful to an unborn baby. If you want to try to get pregnant, ask your doctor for advice.

Know your body

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.

Be breast aware

When it is found early, breast cancer can often be treated successfully. It is important to be aware of how your breasts and chest normally look and feel, so you can recognise any changes.

You could try checking in the bath or shower using a soapy hand, or when you are getting dressed. If you are not sure how to check your breasts and chest, ask your practice nurse or GP for advice.

Your breasts and chest will change as you get older and at different stages of your life. For women, this happens:

  • before the menopause – breasts can feel different at various times of the month
  • before you start a period – they may feel tender and lumpy, especially near the armpits
  • after the menopause – breasts normally feel soft, less firm and not lumpy.

In most cases, changes to your breasts or chest do not mean you have cancer. But you should see your GP if you notice a change that is not normal for you, such as:

  • a new lump or an area that feels thicker in your breast or armpit
  • a change to your nipple, such as a rash, discharge or the nipple changing direction or turning in
  • a change to the skin on your breast or chest, such as dimpling or redness
  • a change in the size or shape of your breast
  • constant discomfort or pain in one breast.

Know the signs of ovarian cancer

Your GP should offer cancer tests if you have any of these symptoms for no reason, or you get these symptoms regularly (especially if it is more than 12 times a month):

  • A long-lasting bloated or swollen tummy.
  • Feeling full quickly when you eat, or loss of appetite.
  • Pain in the lower tummy or back.
  • Peeing (passing urine) more often than usual or more urgently (feeling like you cannot hold on).

Other symptoms may include the following:

  • A change in your normal bowel habit (diarrhoea or constipation).
  • Weight gain or weight loss.
  • Unexplained or extreme tiredness (fatigue).
  • Vaginal bleeding after the menopause.

If you are aged 50 or older and develop symptoms of irritable bowel syndrome (IBS) for the first time, you should also have tests. IBS can cause bloating and changes in bowel habit, but it does not usually start after 50.

Most women with these symptoms do not have ovarian cancer, but it is important to get them checked.

Be prostate aware

Most prostate problems are not caused by cancer. But you should see your GP if you:

  • have difficulty peeing (passing urine)
  • need to pee more often than usual, especially at night
  • have a weak flow of pee
  • urgently need to pee, and leak if you do not get to a toilet quickly
  • have a feeling of not completely emptying your bladder after peeing
  • have blood in your pee or semen
  • have pain when peeing or ejaculating.

These symptoms are usually caused by non-cancerous changes in the prostate rather than by cancer. Prostate Cancer UK has more information about prostate problems.

Other symptoms

Other cancers linked to BRCA1 or BRCA2 mutations are much less common. Always see your GP if you have symptoms that are ongoing or unusual for you.

We have more information about the signs and symptoms of cancer that you may find helpful.

I noticed I had a lump in my breast. But I always had very lumpy breasts during my periods. Then in the shower, I noticed my nipple had turned in.


Health and lifestyle

There may also be factors in your lifestyle that affect your cancer risk. You may reduce your risk of cancer by:

  • not smoking
  • keeping to a healthy weight
  • eating a healthy diet
  • being physically active
  • following the NHS guidelines if you drink alcohol.

Many people who find out they have a high cancer risk decide to improve their lifestyle in these ways. Some people find that a healthy lifestyle makes them feel they are doing everything they can to control their cancer risk.

There is not always clear evidence about how much these factors affect cancer risk in people with a BRCA1 or BRCA2 mutation. However, there is strong evidence that they improve your general health and well-being. Ask your genetics specialist for advice about your risks. Your genetics specialist, GP or practice nurse can give you more information about healthy living.

Planning a family

If you have an inherited cancer gene, there is a 1 in 2 (50%) chance that any child you have could inherit it from you. Your genetics specialist can talk to you about this if you have questions.

Many people choose to have children and accept that the child may have a higher cancer risk. They may feel the child will have the same or perhaps better ways to manage that risk when they grow up.

If you have an inherited cancer gene and want to be sure you do not pass it on to any children, sometimes other options are available.

Pre-implantation genetic diagnosis (PGD)

This test is done during in vitro fertilisation (IVF). Doctors collect egg and sperm cells from you and a partner. They use these to create embryos in the laboratory. They test these embryos for the cancer gene (PGD). The fertility specialist then transfers an embryo that does not have the cancer gene into the woman’s womb.

PGD is not available to everyone. There are age limits, and funding may not always be available. PGD is only done in a few centres in the UK. You may need to travel some distance to have it. You can find more about PGD on the Human Fertilisation and Embryology Authority’s website.

Egg or sperm donation

Some couples decide to use:

  • donor eggs (if the woman has the gene mutation)
  • donor sperm (if the man has the gene mutation).

Prenatal testing

Some couples choose to have a test early on during the pregnancy to check for the cancer gene. The couple can decide whether to continue with the pregnancy when they know the results.

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. You can also talk to our cancer support specialists on 0808 808 00 00. Or you can share your thoughts with members of our Online Community.