Inherited colorectal cancer syndromes

Inherited colorectal cancer syndromes are linked to 5 - 10% of colorectal cancers through inherited genetic variants.

What are Inherited Colorectal Cancer Syndromes?

Colorectal cancer is one of the most common cancers in Australia. About 30% of people with colorectal cancer have a family history of the disease, and up to 10% have genetic changes linked to inherited cancer syndromes like Lynch syndrome and Familial Adenomatous Polyposis (FAP) or MUTYH-Associated Polyposis (MAP).

Our Inherited Colorectal Cancer Syndrome tests

Lynch Syndrome Panel

Lynch syndrome is a common inherited condition that increases the risk of colorectal cancer, endometrial cancer, and other cancers. It is caused by specific changes in certain genes (MLH1, MSH2, MSH6, PMS2, and EPCAM).

Genetic testing can identify these changes, allowing patients and their families to take steps to reduce their cancer risk through regular screening and preventive measures.

FAP/MAP Panel

This test looks for genetic changes linked to Familial Adenomatous Polyposis (FAP) and MUTYH-Associated Polyposis (MAP), which are conditions that increase the risk of developing colorectal cancer.

  • FAP is a condition where hundreds to thousands of polyps (growths) form in the digestive tract, often leading to cancer before age 40 if not treated. FAP is usually caused by changes in the APC gene, and in about one-third of cases, it happens without a family history of the disease.
  • MAP is similar to FAP but is caused by changes in the MUTYH gene and is inherited differently. People with MAP also develop multiple polyps, which again significantly increases the risk of developing colorectal cancer.

Identifying these pathogenic variants early allows for proactive management, including enhanced screening, preventive surgeries, and other risk-reducing strategies.

Why Get Tested?

When there is a family history, both the Lynch Syndrome and FAP/MAP Panels can help in assessing your inherited colorectal cancer risk. Knowing your genetic status allows for earlier, more personalised interventions, potentially preventing cancer or catching it early when it's easier to treat.

Your doctor will be able to advise if you are eligible for Medicare or not. Pre-test genetic counselling is required prior to undertaking genetic testing.

Patients' process

Step 1

Get a doctor's request

Your doctor will discuss your family history with you, and whether testing for inherited colorectal cancer syndromes could be useful. They will complete a dedicated request form and provide pre-test genetic counselling, which you will need to sign that you have received.

Step 2

Have a blood test

Medicare may not cover the cost of this test. If you will need to pay for your test, do so here prior to having your blood taken at a local Healius Pathology collection centre. Write your receipt number on the request form.

Step 3

Results consultation with your doctor

Your results will be delivered to your doctor within 4 - 5 weeks of your sample arriving at the laboratory.

FAQ

Who should consider having this test?
Why is genetic counselling so important?
Which genes are covered in these tests?
What do the results mean?
How long will it take to receive the results?
What happens is I change my mind about testing?
Does Medicare or private health insurance cover the cost of testing?
Refund Policy

Resources

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Why screen patients for inherited colorectal cancer syndromes?

Colorectal cancer is the third most common type of newly diagnosed cancer in Australia. It is estimated that 30% of patients with colorectal cancer have a family history of the disease, and up to 10% have genomic variants associated with inherited cancer syndromes including Lynch syndrome and familial adenomatous syndromes FAP and MAP.

MBS rebated diagnostic and predictive testing for the genes associated with these syndromes is now available for patients who meet criteria and when requested by a specialist medical practitioner. Guidelines recommend anyone with a Lynch syndrome risk of ≥5% as calculated by risk prediction models have germline testing however, MBS guidelines require a risk of ≥10%.

When is testing useful?

Detection of pathogenic variants in genes associated with inherited colorectal cancer syndromes:

•  confirms a diagnosis in patients with a personal history of cancer

•  provides genotype-specific information on lifetime risk of cancers

•  directs patient management, including surveillance and consideration of prophylactic surgery, based on genotype-specific risks

•  guides testing of at-risk (asymptomatic) family members

Our panels

Lynch syndrome is one of the most common cancer predisposition syndromes, and confers a significantly increased lifetime risk of colorectal cancer, endometrial cancer and multiple other cancers. A diagnosis of Lynch Syndrome is confirmed by the detection of a pathogenic germline variant in one of the MMR genes (MLH1, MSH2, MSH6 and PMS2) or the EPCAM gene. These are found in our Lynch syndrome panel.

Familial adenomatous polyposis is an autosomal dominant disorder characterised by numerous (>100 to 1000s) gastrointestinal adenomatous polyps that almost inevitably progress to CRC by age 40. A variant of the disorder, attenuated FAP, has a later onset, fewer polyps (usually <100) and reduced occurrence of extra-intestinal manifestations. Both forms of FAP are caused by pathogenic variants of the APC gene. Up to one third of cases are due to de novo (new) variants and therefore have no family history of disease.

MUTYH-associated polyposis is an autosomal recessive disorder characterized by attenuated adenomatous colorectal polyposis (usually 15-100 polyps) and significantly increased lifetime risk of colorectal cancer. MAP is caused by biallelic pathogenic variants of the MUTYH gene.

The APC and MUTYH genes are both found in our FAP/MAP panel.

Steps

Step 1

Patient consultation

Discuss your patient’s family history of cancer with them and whether testing for inherited colorectal cancer syndromes would be beneficial. Complete a dedicated request form and pre-test genetic counselling, ensuring the patient signs the form once completed.

Step 2

Sample collection

Patients who are not covered by Medicare will need to prepay for the test here and note their receipt number of the request form. They then attend their most convenient collection centre with their signed request form.

Step 3

Result discussion

Results are delivered to you by your preferred method approximately 4 weeks after the patient has their blood collected.

FAQ

Genetic counselling
Lynch syndrome risk calculators
Understanding Medicare item numbers for inherited colorectal cancer syndromes

References