The American Cancer Society estimates that in 2010, more than 22,000 people in the United States will be newly diagnosed with a brain or spinal cord tumor. The exact cause of brain tumors is not understood completely, but several risk factors can increase the likelihood of developing a brain tumor.
Genetic Factors
The majority of cancers, including brain cancer, are not hereditary, according to the American Brain Tumor Association, or ABTA. That being said, several genetic syndromes can increase the risk of developing a brain tumor. These syndromes include: NF1, NF2, Turcot's, Gorlin's, tuberous sclerosis and Li-Fraumeni. Risk factors can also develop as we age, for example when a gene starts functioning abnormally or becomes inactive. Tumor suppressor genes, oncogenes, growth factors and DNA repair genes are all examples of genes that can contribute to the development of a brain tumor if they start functioning abnormally.
Radiation Exposure
The American Cancer Society says that the link between radiation exposure and brain tumors is the best established environmental risk factor. This radiation exposure typically comes from radiation given to treat previous cancers, especially in children with leukemia who may have had radiation to the brain as part of their treatment regimen. The brain tumors do not develop immediately; they usually form 10 to 15 years after the exposure. The risk of developing a brain tumor after radiation therapy for cancer is small, but it exists; for this reason, a physician's decision to irradiate the head involves a careful examination of risks and benefits.
Disorders of the Immune System
Damaged immune systems increase your risk of developing lymphomas of the brain, says the American Cancer Society. Typically, lymphomas form in lymph nodes, and while lymphoma in the central nervous system is rare, it does occur. Immune system impairment may be congenital or acquired, but both types increase the risk of developing brain cancer.
Demographic Variables
Race and age may play a role in developing brain tumors, according to the Mayo Clinic. Caucasians suffer brain tumors more frequently than individuals of other ethnicities, with the exception of a brain tumor called a meningioma, which is most commonly diagnosed in African-Americans. Advancing age increases the risk of developing brain tumors, although brain cancer can be diagnosed at any age.
Uncertain Risk Factors
Several risk factors have been tentatively linked to brain tumors but are still being studied to definitively determine actual risk. Cell phones have been linked to brain tumors because of the radiation they emit, but it is not the same kind of radiation used in radiation therapy, says the American Cancer Society. Other possible risk factors include the use of aspartame, a sugar substitute; certain kinds of viruses; exposure to chemicals, such as vinyl chloride and petroleum products; and exposure to electromagnetic fields generated by power lines.
References
- American Brain Tumor Association: Causes and Risk Factors
- American Cancer Society: What are the risk factors for brain and spinal cord tumors?
- Mayo Clinic: Brain Cancer: Risk Factors
- American Cancer Society: Do we know what causes brain and spinal cord tumors in adults?
- American Cancer Society: What are the key statistics about brain and spinal cord tumors?
