Getting Tested
The First Step
The first step towards getting tested is to create a comprehensive picture of your family’s cancer history. This is called a cancer family history. This powerful tool can help guide your GP or medical professional towards identifying your chance of having Lynch syndrome and the need to be tested.
Creating a comprehensive family history involves carefully documenting each member of both your mother’s and father’s family and outlining any cancers they may have been diagnosed with and at what age. Where relevant, it may also be important to describe the outcomes of their cancer diagnoses. Lynch Syndrome Australia has developed a Family Cancer Tree tool which may assist you in this process.
Indicators of Lynch Syndrome
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N.B: If you have had a Lynch syndrome-associated cancer before you were 50 years old then, regardless of your family history you should insist on being referred to a genetics service to discuss whether you might have Lynch syndrome. Although it is best practice for every bowel cancer or endometrial cancer tumour in patients under 50 to be sent for testing, unfortunately, this does not happen every time.
The Second Step
The second step in getting tested for Lynch syndrome is to speak to your doctor or surgeon. They will be able to advise you on the need for genetic testing for yourself or within your family.
If it is decided that genetic testing is appropriate, you will be referred to the familial cancer service (which may be public or private) in your state. At your initial appointment you will meet with a genetic specialist (counsellor) who has expertise in Lynch syndrome. Genetic counsellors assist you and your family to understand the genetic testing process and support your decision making throughout the testing.
The Third Step
If you decide to go ahead with genetic testing, a DNA sample (blood or otherwise) will be collected and analysed in a laboratory. Your results will either come back as:
1. A Genetic Mutation is Not Found
The genetic test did not find a known Lynch syndrome mutation in your genes. Your genetic counsellor may tell you that this means you don’t need to follow a specific surveillance regime and your children will not need to tested.
2. A Genetic Mutation is Found
The genetic test found a known Lynch syndrome mutation in your genes. Additional family members may now be offered predictive testing to find out whether they too have Lynch syndrome (i.e. the same genetic mutation).
3. Variant of Unknown Significance
A mutation was identified in your genes however it is not yet known whether it results in you having an increased chance of developing cancer in your lifetime (i.e. it is not clear whether you have Lynch syndrome). Your geneticist and/or genetic counsellor will discuss this further with you.
If you receive a diagnosis of Lynch syndrome, you will be told which of the genes is mutated in your family. If you do not, it is important to ask because your gene variant can affect your chance of developing cancer and therefore the surveillance management you will need to undertake.
After Diagnosis
If a family member has been confirmed to have Lynch syndrome, predictive testing can be offered to other relatives on the affected side of the family.
This is important as it gives family members the opportunity to learn whether or not they too have a greater chance of developing cancer in their lifetime. This knowledge means that they can reduce that risk by undertaking preventative measures and engaging in their own surveillance plans aimed at detecting cancer at an early stage and before it becomes life-threatening.