Certain factors can make one person more likely to get a brain tumor than another person. These are called risk factors. Although such risk factors do exist, a person who has one or more risk factors will not always get a brain tumor. In fact, you can have many risk factors and still not get a brain tumor, or you can have no known risk factors and still get the disease.
Head trauma is not a risk factor for brain tumors. Doctors do not know exactly what causes brain tumors, although they have found these possible risk factors:
If you've been exposed to radiation through an accidental exposure or radiation treatment to the head for other cancers, it may increase your risk of getting a brain tumor.
If you've been exposed to certain pesticides and chemicals, you may have an increased risk of brain cancer. Examples of these chemicals are petroleum products and polyvinyl chloride, an odorless gas used in plastics manufacturing. Not all studies have found that these chemicals increase risk, however.
If you have a damaged immune system, you may be at higher risk of developing a brain lymphoma. The defect in the immune system may exist from birth. This is called a congenital defect. It may also result from treatments for other cancers, from drugs used to prevent the rejection of transplanted organs, or from AIDS. This is called an acquired defect.
There may be a genetic risk of developing a brain tumor. Very few brain tumors run in families, meaning most are not hereditary. Hereditary brain tumors most often start at a young age and are often linked to inherited syndromes, such as neurofibromatosis or Li-Fraumeni syndrome.