There are tests you can have to find out if you have Lynch syndrome.
The main test for Lynch syndrome is a genetic test on a sample of your blood or saliva.
Genetic testing finds changes in genes that can cause health problems. It is sometimes called genomic testing.
Getting a genetic test for Lynch syndrome
We may offer you a genetic test for Lynch syndrome if:
- you are having tests for certain cancers
- a family member has Lynch syndrome
Before you can have a genetic test you will meet with a doctor, nurse or genetic counsellor - a specialist who can give you information about genetic testing and results. This is to help find out if testing is right for you.
What to expect at your appointment
If you are having tests for certain cancers
When you are having tests for cancer your doctors usually take a sample of the tumour. They send it to a lab where a histopathologist (doctor who specialises in studying of structure of organs, tissues and cells) will check if it's cancer. This is called a biopsy.
The histopathologist can also test the sample to check for certain proteins, called mismatch repair proteins. This may also be called a cancer tissue test, tumour test or immunohistochemistry test for MMR proteins.
They may do this if you have:
- bowel cancer (cancer of your colon or rectum)
- endometrial cancer (cancer of the lining of your womb)
- certain types of ovarian cancer (endometrioid and clear cell)
If this test finds your mismatch repair protein is missing this means you may have Lynch syndrome. Your healthcare team may refer you for a genetic test.
If you decide to have a genetic test, the results can help your healthcare team:
- confirm you have Lynch syndrome
- plan your treatment
- check for a clinical trial that might be suitable
What your tumour test results mean
If a family member has Lynch syndrome
If a family member has a Lynch syndrome diagnosis their healthcare team will encourage them to tell their family.
If a family member has Lynch syndrome you can ask your GP to refer you to a cancer genetics service.
Family members who can get a test include:
- parents
- brothers or sisters
- children age 18 and over
Ask your relative for a copy of their Lynch syndrome test result or a letter you can bring to your GP appointment - if they have one.
If you get a Lynch syndrome diagnosis, your relatives can ask their GP to refer them to a cancer genetics service. This is known as cascade testing. It is also known as predictive testing.
Lynch syndrome test results can help your healthcare team:
- understand your and your family's risk of developing cancer in the future
- make a plan to help reduce your risk of cancer
Non-urgent advice: Go to your GP if:
- you are worried about a family history of cancer
- have symptoms of cancer
Pre-test appointment
Before you can have a genetic test you will meet with a doctor, nurse or genetic counsellor.
If your GP or consultant refers you to a cancer genetics service, someone from that service will contact you to arrange an appointment.
If you are having tests for certain cancers your healthcare team may organise an appointment at your hospital for you.
At the appointment your doctor, nurse or genetic counsellor will give you guidance about Lynch syndrome.
They will help you understand:
- your cancer risk
- how cancer-related gene changes are inherited
- the risks and benefits of having a genetic test
- what a genetic test means for you and your family
- the potential results of your test and what they mean
- how your family members may be affected if the test shows a serious health condition runs in your family
- the risk of passing on a health condition to your children
- how to manage your risk of getting cancer
They can can also tell you about:
- patient support groups
- psychological help
Deciding to have a genetic test for Lynch syndrome
Deciding to have genetic testing is a personal choice. It can be a complex decision. You do not have to decide straight away.
If you choose not to have a genetic test
Not everyone will choose to have genetic testing.
If you choose not to and have a family history of cancer your healthcare team can make a plan to help reduce your risk of cancer.
If you have cancer and decide not to have a genetic test for Lynch syndrome, you will still get treatment and support from your healthcare team.
Giving your consent for a genetic test
Your healthcare team will need to get your consent (permission and agreement) before you have a test for Lynch syndrome.
You can withdraw your consent - you must do this in writing. For example, you may not want us to store your DNA after tests have been completed.
What a genetic test involves
If you agree to a genetic test for Lynch syndrome you will have a genetic test on a sample of your blood or saliva.
Your doctor, nurse, genetic counsellor or phlebotomist (a specialist in taking blood samples) may take a sample of blood or saliva.
They can do this straight after your appointment - or at a later stage if you need more time to decide. In some cases they may send a saliva kit to your home.
They send your blood or saliva sample to a lab to be tested for Lynch syndrome.
Make sure not to eat, drink, chew gum or smoke immediately before your appointment. This is so your healthcare team can do a mouth swab for a saliva test after your appointment, if you choose to.
If you have a family history of cancer
You can talk to your GP if you have a family history of cancer that worries you.
They will need to know your family history of cancer.
For example:
- who in your family had cancer
- what age they were when diagnosed with cancer
- what type of cancer they had
Your GP may refer you for an assessment at a family history clinic in a hospital.
