Primary brain tumors originate in the brain. Metastatic tumors are caused by cancerous cells that originate elsewhere in the body and travel through the lymphatic system to a new site in the brain. According to the Central Brain Tumor Registry, an estimated 114,000 patients are diagnosed with brain tumors a year, an increase of more than 5 percent since 1995. Males and females of all ages, races and ethnicities are vulnerable to brain tumors. In general, brain tumors are most common among the middle-aged and elderly.
Genetic diseases cause a few types of primary tumors.
However, the origin of most brain tumors are unknown. Medical researchers speculate that several factors, possibly working together, are responsible. Potential culprits being investigated include family history, damaged genes, viruses, environmental factors such as chemicals and electromagnetic fields, occupational factors and injuries. Three types of therapy are commonly used, either alone or in combination. These are surgery, radiotherapy and chemotherapy.