A risk factor is anything that increases a person’s chance of developing a certain condition or disease, such as cancer. In adults, lifestyle and environmental factors (such as smoking or exposure to certain chemicals) can be significant risk factors for developing certain types of cancer. In children, very few risk factors have been identified that increase the chance of developing cancer. For most children with cancer, the underlying cause is unknown.
Even if your child has a risk factor, it does not mean they will develop cancer. Many children with a risk factor will never develop cancer, while others with cancer may have had no known risk factors. Even if a child with a risk factor develops cancer, it is usually hard to know how much that risk factor contributed to the development of their disease.
The causes of leukaemia are not well understood, but factors associated with a higher chance of developing leukaemia include the following:
Children who have a brother or sister – especially a twin – with leukaemia have a slightly higher chance of developing leukaemia themselves.
Some changes in a child’s chromosomes or genes can lead to leukaemia. Certain genetic conditions can also increase a child's risk of developing leukaemia, including:
- Down syndrome
- Klinefelter syndrome
- Shwachman syndrome
- Bloom syndrome
- Li–Fraumeni syndrome
- Noonan syndrome
- Wiscott–Aldrich syndrome
- neurofibromatosis type
- Fanconi anaemia
If your child is diagnosed with one of these genetic conditions, they will need specific follow-up. The health care team will advise which ongoing tests your child will need.
Cancers in children that are linked to genetic conditions may also affect the risk for other family members. Speak to your child’s treatment team to see whether genetic counselling is recommended for you or your family.
Exposure to radiation
Children who are exposed to radiation, or who were exposed to X-rays before they were born, have a higher risk of developing leukaemia. Children who have previously had radiation therapy (radiotherapy) to treat cancer also have a higher chance of developing leukaemia.
Children who have been treated with chemotherapy before, either for leukaemia or for another type of cancer, have a higher risk of developing leukaemia.