What're the risk factors for brain tumors?
Age: Although brain tumors can occur at any age, they're most common in people older than 65. Children younger than 8 appear to be at a higher risk for brain tumors than are older children. Tumors in the central nervous system are now the most common cancers in children, but they are still rare. About 1,500 children are diagnosed with brain tumors each year,
although half are benign. Brain tumors in children are more likely to occur in the cerebellum, the midbrain, or the optic nerve.
Environmental or occupational risk factors: The only proven risk factor for brain tumors to date is radiation from ions (such as with radiation treatment.) Some types of brain tumors appear to occur more frequently in people who are exposed to radiation or certain chemicals, such as those who work in oil refining, rubber manufacturing, and chemical and nuclear industries. But a definite link between exposure to chemicals and brain tumors hasn't been proved. Similarly, electromagnetic fields and the use of cell phones have been studied as causes of primary brain tumors, but no definitive medical evidence indicates that either causes brain tumors.
Diseases associated with brain tumors: Neurofibromatosis type 1 (von Recklinghausen's disease) is the most common inherited cause of brain or spinal cord tumors. The disorder may be associated with optic gliomas or other gliomas of the brain or spinal cord as well as with neurofibromas of peripheral nerves. The gene abnormality responsible for this disorder has been cloned and its protein product identified. Neurofibromatosis type II is less common than von Recklinghausen's disease. It is associated with tumors of both acoustic (hearing) nerves and in some people with meningiomas or spinal cord ependymomas. The gene responsible for neurofibromatosis Type II has been cloned and its protein product identified. Those with tuberous sclerosis (another inherited condition) may have noninfiltrating subependymal giant cell astrocytomas in addition to benign tumors of the skin, heart, or kidneys. Von Hippel-Lindau disease is associated with an inherited tendency to develop hemangioblastomas (blood vessel tumors) of the cerebellum or retina as well as renal cell (kidney) carcinomas. The Li-Fraumeni syndrome results in an increased risk of developing breast cancer, soft tissue sarcomas, leukemia, adrenal gland cancers, and gliomas. |
