Glioblastoma multiforme, the most aggressive and most common type of primary brain tumor, comprises nearly 25 percent of primary brain tumors, the University of Southern California states. Primary brain tumors, brain tumors that arise in the brain rather than metastasizing from other areas, affect around 8 percent of people in the United States each year, according to 2010 information from the International RadioSurgery Association. Most people who develop glioblastoma are over age 50 and have a poor prognosis, usually less than six months to a year, the University of Connecticut states. Several factors can cause glioblastoma.
Inherited Genes/Genetic Diseases
While only 5 percent of primary brain tumors are associated with inherited genes, 80 percent of people with glioblastomas have more than one copy of chromosome seven, the IRSA reports. Gene mutation can lead to abnormal cell formation. Inactivation of a gene that suppresses tumors, called P53, may also increase the risk of developing glioblastoma multiforme, the University of Connecticut reports. Certain genetic disorders also increase the chances of developing glioblastomas, including neurofibromatosis, a nervous system disorder. Genetic diseases associated with increased tumor growth, such as Von-Hippel-Lindau disease, tuberous sclerosis, Li-Fraumeni syndrome and Turcot's syndrome, a syndrome associated with colorectal polyps and central nervous system tumors.
Previous Radiation Treatment
Previous radiation treatment with high-dose ionizing radiation for a brain tumor can on rare occasions cause secondary glioblastomas, according to the IRSA. Previous radiation to the brain increases the chance of developing for 20 to 30 years after the original treatment, MedlinePlus reports.
Chemical Exposure
Chemical exposure to formaldehyde, pesticides and petrochemicals may increase the chances of developing glioblastoma. Working in certain industries such as farming, pharmaceutical manufacture or crude oil refining, or being employed as an electrical worker, chemist, pathologist, artist or embalmer may also increase the risk of developing glioblastoma according to some studies, the National Cancer Institute reports.
Unproven Causes
Research has failed to prove a definite connection between cell phone use, long-term use of dark hair dye and dietary factors, such as artificial sweeteners and processed meats, the National Cancer Institute states, although research into these areas is ongoing.
