Dr Ren Manias, Consultant Paediatric Oncologist at Southampton General Hospital, and Contact's medical adviser
What is inherited cancer risk?
Cancer predisposition syndromes are rare conditions that result from genetic mutations that increase the chance of developing cancer compared to the risk for the general population. In these conditions, genetic traits or mutations are passed from parents to children, so several close relatives may be affected. Depending on the specific mutation, hereditary cancer may increase a person’s risk of developing a specific type of cancer, cancer at an early age, or multiple types of cancer.
How common are hereditary cancers?
About 10% of children with cancer have an inherited mutation that increases their risk of cancer. If your child’s cancer is thought to be related to an inherited mutation, your consultant will talk to you about the gene it affects, what type of mutation it is, and whether there is a chance that other family members may also have that gene.
What are the most common cancer predisposition syndromes and what types of cancer do they cause?
- Fanconi anaemia: A disease that prevents bone marrow from making enough new blood cells. Fanconi anaemia increases a person’s risk of developing several types of cancer, including acute myeloid leukaemia (AML) and squamous cell carcinoma
- Xeroderma pigmentosum: Causes extreme sensitivity to sunlight, leading to a high risk of developing skin cancer
- Li-Fraumeni syndrome: An inherited genetic predisposition to multiple types of cancer, which increases a person’s risk of developing cancer at any age. This condition commonly leads to cancer in the brain, bones, soft tissue, blood and breasts
- DICER1 syndrome: A mutation in the DICER1 gene that increases a person’s chance of developing tumours in the lungs, kidneys, ovaries and thyroid
- Neurofibromatosis type 1: Causes changes in skin colour, non-cancerous tumours and cancerous peripheral nerve sheath tumours. It also increases a person’s risk of developing brain tumours and blood cancers
- Down’s syndrome: Children with Down’s syndrome have a higher risk of developing blood cancers like acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML) but are less likely to develop solid tumours
- Hereditary retinoblastoma: Mutations in the RB1 gene lead to retinoblastoma (an eye cancer that usually develops in the first five years of life) and increased risk of other types of cancer in later life, including common adult cancers and sarcomas
What happens if there is a concern your child's cancer is inherited?
If there's a concern that your child’s cancer is inherited, your consultant will talk to you about genetic testing and refer you to a geneticist for counselling. Genetic testing is usually done initially by testing the child who has cancer, by examining a sample of blood to see if there's a mutation.
We sometimes do something called multigene panel testing to look at the DNA of several related cancer genes at the same time. If a mutation is found, we can discuss the implications and offer to test other family members to see if they have it too.
Have a question to ask one of our experts?
Please get in touch by emailing info@cclg.org.uk or via DM on our social channels.
From Contact magazine issue 98 - Spring 2023
