Genetic testing for cancer risk

A gene change or mutation is a permanent change in the DNA that makes up a gene . This can be inherited from a parent.

Changes to your genes can also happen during your lifetime. For example too much ultraviolet (UV) radiation from the sun can damage DNA in your skin cells and cause skin cancer. This is an environmental factor. 

Doctor also call gene changes other terms such as gene:
•    alterations
•    variants
•    faults

 

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

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 appointment?

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 gene change.

In certain situations, the genetic counsellor might suggest you have regular screening because of your family history. 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 gene change

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 gene change

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 pick up a gene change. 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 gene change. 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 gene change. This is usually part of the process of deciding whether to have the test or not. The options will depend on:

• the particular gene change that you may have
• which cancers you are at increased risk of developing
• your age and plans for the future

If a gene change 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 an inherited gene change, 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 gene change. 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)
• retinoblastoma (RB1)
• multiple endocrine neoplasia (MEN)
• Li-Fraumeni Syndrome (LFS)
• Von Hippel-Lindau (VHL) disease
• hereditary Leiomyomatosis and renal cell cancer (HLRCC)
• 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 gene change 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 gene change 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. And that testing is performed in an accredited genomics laboratory. 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.

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.

 

NHS Jewish BRCA testing programme  

Having a Jewish ancestry means that you are at a higher risk of carrying a  BRCA1 or BRCA2 gene change. Having this can increase their risk of developing cancer in the future. 

NHS England now offer testing to look at the BRCA genes in people of Jewish ancestory. To be able to have this testing you must live in England and:

• have at least one Jewish grandparent
• be 18 years of age or over