Although risk factors often influence the development of a brain tumor, most do not directly cause a brain tumor. Some people with several risk factors never .
Sometimes, people with a brain tumor do not have any of these changes. Or, the cause of a symptom may be a different medical condition that is not a brain .
These tumors are considered malignant or cancerous growths. In the USA alone, metastatic tumors in the brain affect nearly one in four patients with cancer and .