Cowden Syndrome

Frequently Asked Questions (FAQs)

Q: Who is the best person in the family to undergo genetic testing?
A: Genetic testing is usually offered to the family member whose personal history is most suggestive of a hereditary cancer syndrome (e.g., someone with a personal history of tumours/cancer at a young age or clinical presentations suggestive of CS).

It is usually not advisable to test someone without a history of cancer, tumours or clinical features.

The genetic test results of an asymptomatic individual may have limitations:

• If they were to receive a negative result, it may not mean that there is no hereditary cause of tumours/ cancer in the family. The individual being tested may not have inherited it, but others in the family may have, or the faulty gene may not have been identified yet.
• The result is only useful to the asymptomatic person being tested and their children, but not to their parents, siblings and other seconddegree family members.

Once the faulty gene in the family is identified, genetic testing can be offered to other family members, including those who do not have cancer. This would help in understanding if they have inherited the faulty gene and if so, tailoring their management to manage or reduce their risks.

Q: Is testing recommended in children?
A: As children with CS may develop medical issues or tumours/cancer at a young age, genetic testing for CS is recommended in young children. However, genetic testing is only offered when the child has a personal history suggestive of CS, or if a faulty gene is identified in the family (i.e., a parent has CS).

Common Myths & Misconceptions

1. If my genetic test result is positive, it means that I have or will have cancer, or my cancer will recur.

   FALSE. Results from a genetic test do not determine the likelihood of a tumour/cancer being present or tumour/cancer recurrence. Instead, a genetic test that indicates you have CS means you may face an increased risk of tumours/cancer developing over your lifetime.
   
   

2. If I test positive, it means that my children will also have CS.

   FALSE. If you have a genetic test result confirming a diagnosis of CS (a faulty PTEN gene is identified), it means that your children have a 50% (1 in 2) chance of inheriting the same faulty PTEN gene.
   
   

3. I have two brothers, so one will inherit the faulty gene and one will not, because there is a 50% chance.

   FALSE. Each first degree relative has a 50% chance of inheriting the faulty gene. One sibling’s result does not determine the chances of the other sibling.
   
   

4. I only need to tell my brothers, sisters and children. My extended relatives (aunties, uncles, cousins) are too far removed so I do not need to let them know.

   FALSE. Distant relatives can inherit the faulty gene. It is important to let them know so that they can consider their own genetic testing (predictive testing) to understand their risk of developing tumours/cancer.
   
   

5. I (or my relative) already had cancer, so I (or my relative) need not undergo genetic testing.

   FALSE. Individuals who have been diagnosed with cancer previously should still consider genetic testing, especially if their personal history is suggestive of CS. They may be at risk of developing another tumour/cancer, for which there are early screening strategies that can help detect tumours/cancer at a early and manageable stage.
   

Download the Cowden Syndrome brochure.