A risk factor is anything that affects your chance of getting a disease such as a brain or spinal cord tumor. Different types of cancer have different risk factors. Some risk factors, like smoking, you can change. Others, like your age or family history, can’t be changed.
Most brain tumors are not linked with any known risk factors and have no obvious cause. But there are a few factors that can raise the risk of brain tumors.
The best known environmental risk factor for brain tumors is radiation exposure, most often from radiation therapy to treat some other condition.
Most people with brain tumors do not have a family history of the disease, but in rare cases brain and spinal cord cancers run in families. In general, patients with familial cancer syndromes tend to have many tumors that first occur when they are young.
Neurofibromatosis type 1 (NF1)
This genetic disorder, also known as von Recklinghausen disease, is the most common syndrome linked to brain or spinal cord tumors. People with this condition have higher risks of schwannomas, meningiomas, and certain types of gliomas, as well as neurofibromas (benign tumors of peripheral nerves). Changes in the NF1 gene cause this disorder. These changes are inherited from a parent in about half of all cases. In the other half, the NF1 gene changes occur before birth in people whose parents did not have this condition.
Neurofibromatosis type 2 (NF2)
This condition, which is much less common than NF1, is associated with vestibular schwannomas (acoustic neuromas), which almost always occur on both sides of the head. It is also linked with an increased risk of meningiomas or spinal cord ependymomas. Changes in the NF2 gene are responsible for neurofibromatosis type 2. Like NF1, the gene changes are inherited in about half of cases or may occur before birth in children without a family history.
People with this condition may have subependymal giant cell astrocytomas (SEGAs), which are low-grade astrocytomas that develop beneath the ependymal cells of the ventricles). They may also have other benign tumors of the brain, skin, heart, kidneys, and other organs. This condition is caused by changes in either the TSC1 or theTSC2 gene. These gene changes can be inherited from a parent, but most often they develop in people without a family history.
Von Hippel-Lindau disease
People with this condition tend to develop benign or cancerous tumors in different parts of the body, including hemangioblastomas (blood vessel tumors) in the brain, spinal cord, or retina, as well as tumors of the inner ear, kidney, adrenal gland, and pancreas. It is caused by changes in the VHL gene. Most often the gene changes are inherited, but in some cases the changes happen before birth in people whose parents don’t have them.
People with this condition are at higher risk for developing gliomas, along with breast cancer, soft tissue sarcomas,leukemia, and adrenal gland cancer, and certain other types of cancer. It is caused by changes in the TP53 gene.
Other inherited conditions are also linked with increased risks of certain types of brain and spinal cord tumors, including:
- Gorlin syndrome (basal cell nevus syndrome)
- Turcot syndrome
- Cowden syndrome
Some families may have genetic disorders that are not well recognized or that may even be unique to a particular family.
Immune system disorders
People with impaired immune systems have an increased risk of developing lymphomas of the brain or spinal cord (known as primary CNS lymphomas). Lymphomas are cancers of lymphocytes, a type of white blood cell that fights disease. Primary CNS lymphoma is less common than lymphoma that develops outside the brain.
A weakened immune system can be congenital (present at birth), or it can be caused by treatments for other cancers, treatment to prevent rejection of transplanted organs, or diseases such as the acquired immunodeficiency syndrome (AIDS).
Unproven effects on brain tumor risk
- Cell phone use
- microwave ovens
- Satellite stations
- Vinyl chloride (a chemical used to manufacture plastics)
- Petroleum products
- Exposure to aspartame (a sugar substitute),
- Exposure to electromagnetic fields
- Infection with certain viruses