Most patients who develop a brain or spinal cord tumor have no clear risk factors. There are only two known environmental risk factors for developing a brain tumor:
- Exposure of the head to x-rays (not including dental x-rays) for the purpose of treating diseases such as cancer. This is seen in less than 5 percent of patients with brain cancer.
- A history of disorders of the immune system, including congenital immune deficiencies, AIDS, and immunosuppression to prevent rejection of transplanted organs or cells. These disorders increase the risk of lymphoma in the brain.
People with certain rare genetic disorders have an increased risk of some brain tumors: Li-Fraumeni syndrome increases the risk of glioma; von Hippel-Lindau disease increases the risk of hemangioblastoma; tuberous sclerosis increases the risk of astrocytoma; neurofibromatosis type 1 or "von Recklinghausen's" disease increases the risk of glioma; and neurofibromatosis type 2 increases the risk of acoustic nerve tumor and meningioma.
Head trauma, exposure to petrochemicals, and consumption of aspartame has been cited as possible risk factors, but no link between these factors and brain tumors has ever been confirmed.
According to recent studies, cell phone use and the nonionizing radiation these phones emit are not risk factors for developing a brain tumor.
