Risks for childhood brain and spinal cord tumours

Some things can affect your risk, or chance, of developing cancer. Certain behaviours, substances or conditions can increase or decrease the risk. Most cancers are the result of many risks. Childhood cancers are rare and there is less known about the risks. Most risks for childhood cancer are not modifiable. This means that you can’t change them.

Most childhood brain and spinal cord tumours develop during the first 10 years of life. Boys are more likely than girls to develop certain types of brain tumours, such as ependymoma or medulloblastoma.

Children with certain genetic conditions have a higher than average risk for childhood brain and spinal cord tumours. Talk to the doctor about your child’s risk.

The following can increase the risk for childhood brain and spinal cord tumours. Most of these risks can’t be changed. Until we learn more about these risks, there are no specific ways you can reduce a child’s risk.

A genetic condition is a disease caused by a change (mutation) in one or more genes. Having certain inherited conditions increases the risk of developing childhood brain and spinal cord tumours.

Neurofibromatosis affects the nervous system. It alters the development and growth of nerve cells (called neurons), causes tumours (called neurofibromas) to grow on nerves and may produce other abnormalities in muscles, bones and skin. Both neurofibromatosis type 1 (also called von Recklinghausen disease or NF1) and neurofibromatosis type 2 (also called NF2) increase the risk for childhood brain and spinal cord tumours.

Von Hippel-Lindau (VHL) syndrome makes blood vessels in the eyes, brain, spinal cord, adrenal glands and other parts of the body grow abnormally. VHL syndrome increases the risk of brain and spinal cord tumours as well as kidney, adrenal gland and pancreatic cancers.

Li-Fraumeni syndrome is associated with an increased risk of developing certain types of cancers before the age of 45, including brain and spinal cord tumours, breast cancer, acute leukemia, adrenal gland cancer and soft tissue and bone sarcomas.

Tuberous sclerosis complex causes non-cancerous tumours to develop in the brain and spinal cord, skin, eyes, heart, lungs and kidneys. It increases the risk for a type of brain and spinal cord tumour called subependymal giant cell astrocytoma.

Turcot syndrome causes many polyps to develop in the colon. Turcot syndrome increases the risk of colorectal cancer and brain and spinal cord tumours.

Basal cell nevus syndrome is also called Gorlin syndrome or nevoid basal cell carcinoma syndrome. It causes different problems with the skin, eyes, nervous system, endocrine glands and jawbone. Basal cell nevus syndrome increases the risk of developing basal cell carcinoma skin cancer and a type of brain tumour called medulloblastoma.

Cowden syndrome causes many non-cancerous growths (called hamartomas) to develop in different parts of the body, but most commonly in the skin, breast, thyroid, colon and intestines and inside the mouth. Cowden syndrome increases the risk of developing certain cancers, including brain and spinal cord tumours.

Rubinstein-Taybi syndrome (RSTS) is also called broad thumb-hallux syndrome. RSTS increases the risk of developing different types of tumours, including a type of brain tumour called medulloblastoma.

Ionizing radiation is a known risk for cancer. Children who had radiation therapy to the head to treat cancer or another health condition have a higher risk of developing brain tumours. Radiation therapy is only given to the head after carefully weighing the possible benefits and risks. For children with cancer in or near the brain, the benefits of radiation therapy to treat the cancer far outweigh the risk of later developing a brain tumour.

Some imaging tests, such as CT scans, use ionizing radiation to make images. Modern imaging equipment uses the lowest amount of radiation possible, but a CT scan uses higher amounts of radiation than a regular x-ray. The risk of cancer from a single CT scan is small. The risk of cancer from imaging tests must be weighed against their benefits.

Having a physical or genetic birth defect has been linked with childhood brain and spinal cord tumours, but there is not enough evidence to know for sure that it increases the risk.