Genetic testing for cancer risk

Doctor consultation with patient

Some families have an inherited gene fault (mutation) that can increase the risk of developing certain types of cancer. Tests are available for some inherited faulty genes. There are various important issues to consider before making a decision to have a test.

Currently tests are available for gene faults that increase the risk of breast cancer, bowel cancer, ovarian cancer, womb cancer and prostate cancer.

Tests are also available for rare gene faults that may increase the risk of kidney cancer, melanoma skin cancer, pancreatic cancer, thyroid cancer and a type of eye cancer called retinoblastoma.

Tests are not available for other types of cancer genes but research is finding more gene faults all the time and tests are being developed.

Who can be tested for inherited faulty genes?

If cancer runs in your family and you are worried you may get it too, you may be eligible for an NHS genetic test. The test can tell you whether you have inherited a faulty gene that increases your risk of cancer.

You may be eligible for an NHS genetic test if:

  • an inherited faulty gene has already been identified in one of your relatives or
  • there is a strong family history of cancer in your family

Testing for genes that increase the risk of cancer is called predictive genetic testing. A positive result means you have an increased risk of developing cancer. But it doesn't mean that you have cancer or will definitely develop it.

Generally, if you don't have a strong family history, and a faulty gene hasn't been found in any of your relatives, you are not eligible for NHS genetic testing. You can have private testing, but need to think about this carefully. You can find out about private gene testing at the bottom of this page. 

Find out about inherited genes and specific cancer types.

What does genetic testing involve?

There are usually 2 steps to testing for inherited cancer risk genes:

First, a relative with cancer has a blood test to see if they have a faulty gene. Their result will usually be ready in 6 to 8 weeks. This normally has to happen before any healthy relatives can be tested.

Then, if a relative's test finds a faulty gene, you can have a blood test to look for exactly the same gene fault. This type of test is very likely to find the gene fault but on rare occasions it may miss it.

The test results usually come through in about 2 to 4 weeks.

Women of Ashkenazi Jewish descent can often have a test to see if they have a breast cancer gene fault even if they don’t have a relative known to have a faulty gene. This is because there are 3 specific BRCA gene faults (two in BRCA1 and one in BRCA2) that are seen more commonly in the Ashkenazi Jewish population.

How does the GP decide if you are eligible for genetic testing?

Before you can have a genetic test, you need to see your GP. Your GP needs to work out if you have a strong enough family history for a referral to a genetics clinic.

Your GP will ask you some questions about your family history, including:

  • who in the family has had cancer
  • the type of cancer they had
  • how old they were when they were diagnosed

Generally speaking, a strong family history means at least 2 close family members on the same side of the family who have the same cancer or related cancer types, such as bowel and womb cancer.

Read our detailed information about what a family history of cancer means.

If your family history is strong enough your GP will refer you to a genetics clinic.

What happens at the genetics clinic?

At the genetics clinic, you will see a genetics specialist or counsellor who will:

  • look in detail at your family history
  • work out your risk of developing cancer
  • work out whether you need and can have a genetic test

Your first appointment usually lasts about 45 minutes. During this meeting the counsellor will ask you questions about any members of your family who have had cancer.

Most people looking into their family history need to talk to their relatives to find out who has had particular types of cancer and when they were diagnosed. This can be very difficult. Finding out about your family history and talking about cancer can be an emotional time for you and other family members.

You may find it hard to ask your family members whether they have had cancer. In some families, relatives don’t want to discuss it, or may not feel emotionally strong enough. This can cause difficulties. For some people it may raise issues that haven’t been spoken about before, or not for a long time. Your genetic counsellor can help you think about all these issues and find ways of coping with them.

Your genetics clinic appointment is your chance to ask questions. If you’re not sure what to ask you can look at our questions for your doctor.

You could print them out and add any other questions that you have.

What if I don’t have a strong family history?

At the genetic counselling clinic the counsellor may tell you that your family history means you are unlikely to have an inherited faulty gene and you don’t need a gene test. In this case your risk of cancer is the same as other members of the population.

If this happens and you want to reduce your risk of cancer there are things you can do, such as:

  • eating a healthy well balanced diet
  • not smoking
  • exercising regularly
  • keeping to a healthy weight
  • staying safe in the sun

Find out about causes of cancer and reducing your risk.

You might have relatives with cancer. But your family history may not be strong enough to recommend gene testing. In certain situations, the genetics counsellor might suggest you have regular screening. This is more likely if members of your family have breast or bowel cancer. 

You can find out about this in our information about

If the counsellor thinks you may have a faulty gene

Your genetic counsellor will offer you a gene test if you have a strong family history and they think this might be caused by a faulty gene. Your counsellor will discuss the advantages and disadvantages with you.

Advantages and disadvantages of a genetic test

The possible advantages

If you are found to have a gene fault there are things you can do to reduce your risk of developing cancer. For example, you might be able to make certain lifestyle changes. You may be able to have regular screening to detect cancer early (if screening tests are available for that cancer type).

For certain cancers, you might be able to take medicines to lower the risk of developing the cancer. Or you may have risk reducing surgery.

Not knowing whether you have a faulty gene can cause stress and worry. Finding out the result could reduce this worry.

The possible disadvantages

Some genetic test results identify a variation in a gene. But it may not be clear whether it increases your cancer risk and this can be difficult to cope with.

You may have constant worry about developing cancer if the test finds a faulty gene. If the test is positive you may also need to tell other relatives that they may have inherited the gene. 

Possible impacts on insurance

In the future you may find it harder to get health and life insurance after having a genetic test. But, currently the Association of British Insurers (ABI) and the Government have agreed to a ban on asking people for the results of predictive genetic tests for cancer.

Insurance companies can still ask about family history. If you have had a genetic test and it shows that you don’t have a gene, you may choose to tell the insurance company.

If you have had any problems with an insurance company that you can't sort out, you can make a complaint to the Financial Ombudsman Service, free of charge.

How do I decide whether to have a genetic test?

Before you have a test, the genetic counsellor will talk to you about what your options are if you do have a faulty gene. This is usually part of the process of deciding whether to have the test or not. The options will depend on:

  • the particular gene fault that you may have
  • which cancer(s) you are at increased risk of developing
  • your age and plans for the future

Your options if a faulty gene is found may include:

  • screening to pick up cancers early
  • treatment to reduce the risk of cancer, such as medicines or surgery

Read about possible screening and treatment options on the page about getting your genetic test results.

Making a decision about whether to have gene testing can be difficult. It is normal to feel anxious. Thinking about the possibility of getting cancer is difficult. It may also stir up emotions you felt when other family members were diagnosed with cancer and what they went through.

It is important to take time to think it through. Before you decide, it can help to think about these questions:

  • How do you feel about having a test?
  • What will the result really mean for you and your family?
  • What will you do if the result is positive?
  • How will you feel if the result is positive?
  • Will you feel reassured by a negative test?
  • Would you rather not know if you have an increased risk of cancer?
  • Is there treatment to reduce your risk?
  • If there is treatment, would you consider having it?
  • What will happen if you decide not to have the test – could you have screening?

Talking to your family

Deciding whether to have a test is your decision to make. But talking with your family and knowing how they feel may help you to make the choice.

If your test shows that you have a faulty inherited gene, some members of your family may also be at risk of having that gene. They may also need to have testing. It is helpful to think through how you would feel about this and what it would mean for them.

It is worth thinking about who you might need to tell once you know the result. Talking to your genetic counsellor can help you to work this out.

Why do some people decide not to have the test?

After looking at the advantages and disadvantages of testing some people choose not to have a genetics test. They may feel that they don’t want to know if they have a higher than normal cancer risk. Some people decide they don’t want any preventative treatment even if they have a faulty gene. So they may not feel they have anything to gain by having the test.

Only you can decide what is best for you.

Can children have a cancer gene test?

Children under the age of 18 cannot usually be tested. This is because anyone having a genetic test needs to be old enough to make their own choice about whether to have the test or not. They also need to be able to fully understand all the different effects that having the test might have on them and their family members. The exceptions to this are tests for genes that can cause cancer at a young age and for which there is screening that works well. These include

  • familial adenomatous polyposis (FAP)
  • retinoblastoma (RB1)
  • multiple endocrine neoplasia (MEN)

Can I have testing with a private company?

If you don’t have a strong family history of cancer and an inherited gene hasn’t been identified in any of your relatives, you won't be eligible for NHS genetic testing.

If you still want to have a test you will need to pay for it privately.

Find out which genes can be tested for.

It might be helpful to consider the following things about private genetic testing:

  • it's less likely that you have a faulty gene if you don't have any family history of cancer
  • the tests can’t guarantee to predict whether you will develop cancer
  • the cost of a genetic test 
  • tests only look for certain genes

Make sure that genetic counseling is available as part of the service. It's important to get as much information as possible about your situation. And have the opportunity to discuss the advantages and disadvantages of testing and screening.

If you have private health insurance, it’s worth checking that genetic testing is included in this.

It’s difficult to give a balanced view of prices because they can vary. This depends on what tests you have and the company you choose to use. As an example, one company charges £1,300 for counseling and testing of the BRCA1 and BRCA 2 genes.

When contacting a private company you could ask some of these questions.

  • Which genes can you test for?
  • Do I need to have a test?
  • Does the cost include genetic counselling?
  • How will I receive the results?
  • What will the results mean for me and my family?

You can contact some private companies directly. Some private companies ask for a referral from a GP or specialist doctor.


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