Genetic testing for cancer risk
Some people have an inherited gene fault (mutation) that can increase the risk of developing certain types of cancer
Tests are available on the NHS that look for specific inherited faulty genes
You can also have a test that looks at a number of different genes at the same time. This is called a gene panel test
You need to consider important issues before deciding to have a genetic test
Who can be tested for inherited faulty genes?
You may be eligible for an NHS genetic test if cancer runs in your family and you are worried you may get it too. The test can tell you whether you have inherited a faulty gene that increases your risk of cancer.
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.
You may be eligible for an NHS genetic test if:
- an inherited faulty gene has already been found in one of your relatives or
- there is a strong family history of cancer in your family
You need to be referred for genetic testing by a specialist doctor (a genetic specialist or counsellor).
You can have private genetic testing. But you need to think about this carefully. You can find out more about private genetic testing at the bottom of this page.
Find out about inherited genes and specific cancer types.
How does the GP decide if you need to see a genetic specialist?
Before you see a genetic specialist, your GP needs to work out if you have a strong family history of cancer.
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 multiple close family members on the same side of the family who have the same cancer or related cancer types. If you have a strong family history of cancer, your GP can refer you to a genetic clinic.
Read our detailed information about what a family history of cancer means.
What happens at the genetic clinic?
At the genetic clinic, you see a genetic specialist or counsellor. They will:
- look in detail at your family history
- work out your risk of developing cancer
- work out whether you need a genetic test
Your first appointment might be at the clinic or over the phone. During this meeting, the counsellor will ask you questions about any members of your family who have had cancer. And how old they were when diagnosed.
You might need to talk to your relatives to find out who has had cancer. This can be an emotional time for you and other family members. In some families, relatives don’t want to discuss it, or may not feel emotionally ready. Your genetic counsellor can help you think about all these issues and find ways of coping with them.
Your genetic 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 might have.
What if I don’t have a strong family history?
After looking at your family history, the genetic doctor might tell you that it’s unlikely that you have an inherited faulty gene. In this case, your risk of cancer is the same as other members of the population.
In certain situations, the genetic 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:
- screening for women at higher risk of breast cancer
- screening for people at higher risk of bowel cancer
There are also things you can do to reduce your risk of cancer. These include:
- stop smoking
- keeping a healthy weight
- eating a healthy balanced diet
- being more active
- protect your skin and enjoy the sun safely
Find out about the causes of cancer and reducing your risk.
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 of cancer
- they think this might be caused by an inherited faulty gene
Your counsellor will discuss the advantages and disadvantages of genetic testing with you.
Advantages of genetic testing
There are things you can do to reduce your risk of developing cancer if you are found to have a gene fault. For example, you might be able to:
- make certain lifestyle changes
- have regular screening to detect cancer early
- take medicines to lower the risk of developing the cancer
- have risk reducing surgery
Disadvantages of genetic testing
Some genetic test results identify a variation in a gene. But it may not be clear whether it increases your cancer risk or not. This can be difficult to cope with.
You may have a 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 same gene.
Possible impacts on insurance
The Association of British Insurers (ABI) and the Government have agreed that people do not need to disclose the results of genetic predictive tests for cancer.
Insurance companies can still ask about family history. So if you have had a genetic test and it’s negative, 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.
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 cancers you are at increased risk of developing
- your age and plans for the future
If a faulty gene is found, you may have:
- regular 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 genetic testing can be difficult. It is normal to feel anxious. Thinking about the possibility of getting cancer is difficult. It may also bring back 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 regular screening?
- is regular screening available for the cancers that I’m at increased risk from?
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 genetic 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 understand the possible benefits and risks 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)
multiple endocrine neoplasia (MEN)
Li-Fraumeni Syndrome (LFS)
Von-Hippel Lindau (VHL) syndrome
Peutz-Jeghers syndrome (PJS)
Juvenile polyposis syndrome (JPS)
Can I have testing with a private company?
You won't be eligible for NHS testing if you don’t have a strong family history of cancer or if an inherited faulty gene hasn’t been identified in any of your relatives. You can still have a test if you are willing to pay for it privately.
Find out which genes can be tested for.
Before you agree to have private genetic testing, it might be helpful to consider the following things:
- 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 counselling 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.
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 £1,400 for counselling 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?
- how is the test done?
- 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 companies ask for a referral from a GP or specialist doctor.
Cancer: Principles & Practice of Oncology (10th edition)
VT DeVita, TS Lawrence and SA Rosenberg
Lippincott, Williams and Wilkins, 2015
Code on genetic testing and insurance
HM Government and Association of British Insurers, October 2018
NHS England, Last accessed September 2021
US National Library of Medicine, Last accessed September 2021
Familial breast cancer: classification, care and managing breast cancer and related risks in people with a family history of breast cancer
The National Institute for Health and Care Excellence (NICE), June 2013
The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact email@example.com with details of the particular issue you are interested in if you need additional references for this information.