Risk Factors

Primary malignant brain tumors account for about 2% of all cancers. However, brain and spinal cord tumors are the second most common type of cancer in children (after leukemia). According to the American Cancer Society, about 24,000 people in the United States are diagnosed each year with a malignant brain or spinal cord tumor.

Gender

In general, brain tumors are slightly more likely to occur in men than in women. Some specific types of brain tumors, such as meningiomas, are more common in women.

Age

Most brain tumors in adults occur between the ages of 65 - 79. Brain tumors also tend to occur in children younger than age 8. In children, malignant brain tumors are the leading cause of death from solid tumors (non-blood cell cancers).

Ethnicity

The risk for primary brain tumors in Caucasians is higher, as much as two-fold with gliomas, than in people of other races.

Environmental or Occupational Risk Factors

Exposure to ionizing radiation, usually from radiation therapy, is the only environmental risk factor that has been definitively linked to brain tumors. People who receive radiation therapy to the head during cancer treatment have an increased risk of developing brain tumors 10 - 15 years later. Workers in the nuclear industry are also at increased risk.

Despite much research, there is no evidence that electromagnetic field exposure from power lines or household appliances poses any risk. Several recent epidemiological studies have examined the cancer risk of wireless devices such as cellular (mobile) phones, which emit radiofrequency (RF) energy. To date, the studies do not show an association between cell phone use and common brain tumors like gliomas and meningiomas. However, more research is needed to examine potential long-term effects, particularly for children and adolescents.

Researchers have also investigated a number of metals and chemicals including vinyl chloride, petroleum products, lead, arsenic, mercury, and pesticides. To date, there has been no clear evidence that implicates any specific industrial chemical or metal. Research continues.

Medical Conditions

People with impaired immune systems have an increased risk of developing central nervous system lymphomas. Organ transplantation, HIV infection, and chemotherapy are some medical factors that can weaken the immune system.

Review Date: 10/21/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)