Brain Tumor Risk Factors

By Jean Rothman

Medically reviewed by Pat F. Bass III, MD, MPH

There are more than 100 different types of tumors that can start in the spinal cord and brain. The tumors, which may be cancerous (malignant) or non-cancerous (benign), can interrupt numerous normal activities such as thinking, feeling, moving, and even breathing.
Doctors may know the types of tumors, but they don’t yet know the risk factors for them. “Some brain tumors occur as a result of a known genetic condition, such as neurofibromatosis [in which nerve tissues grow tumors], but these represent less than 5 percent of all brain tumors in adults as well as children,” says Andrew Sloan, MD, director of the Brain Tumor and Neuro-Oncology Center at University Hospitals Case Medical Center in Cleveland. “We aren’t sure what causes the other 95 percent, but there are several new trials designed to give us much more data on risk factors than ever before.”
One study, called Gliogene, is gathering information from patients and family members around the world to help determine whether there are genes related to a kind of primary brain tumor called a glioma. A glioma is the most common type of brain tumor. These tumors form from nerve cells called glial cells. These cells form the brain’s supportive tissue.
Gliogene’s goal is to examine tumor samples and blood from about 15,000 people who either have a brain tumor or have a relative who has one. If a genetic link can be identified, it may lead to better brain tumor treatment and preventive strategies in the future. The study involves research teams in the United States, the United Kingdom, Sweden, Denmark, and Israel.

Brain Tumor: Are You at Risk?

There are some known risk factors for developing a spinal cord or brain tumor. But keep in mind that having a risk factor doesn’t mean you’ll get sick — and not having one is no guarantee that you won’t.
The risk of brain tumor may be influenced by these factors:

• Gender. Spinal cord and brain tumors happen more frequently in males than in females, except for meningiomas, which occur more often in females. A meningioma is a type of tumor that grows in the membranes surrounding the brain and spinal cord.
• Race. Caucasians get brain tumors more often than people of other races.
• Age. In general, brain tumors are most often found in adults aged 70 or older. However, children do get brain tumors. They are more common in children who are under 8 years old.
• Family history. If a family member has a glioma, you are more likely to get one.
• Radiation. Studies have found that people who work in the nuclear industry are at increased risk for brain tumors. Also, if you were treated with radiation therapy in the past, either to the head or brain, you may be at a higher risk for meningioma.
• Formaldehyde. Studies show that certain workers who are exposed to formaldehyde are at an increased risk for brain cancer. These include pathologists and embalmers. But people in other kinds of careers that involve exposure to formaldehyde have not been found to be at higher risk.
• Vinyl chloride. Being exposed to this chemical, which is used in the making of plastics, may increase a person's risk of getting a brain tumor.
• Acrylonitrile. Exposure to this material, used in making textiles and plastics, may also be a risk factor.
• Genetic disorders. Having a genetic disorder can increase the chances of having the different kinds of brain tumors, including: Neurofibromatosis (type 1 and type 2), Von Hippel-Lindau disease, tuberous sclerosis, Li-Fraumeni syndrome, Turcot syndrome (type 1 and type 2), Klinefelter syndrome, Nevoid basal cell carcinoma syndrome.

Having the Epstein-Barr virus or AIDS, or having an organ transplant may increase a person's risk of central nervous system lymphoma.
Some studies have raised the question of whether using a cell phone increases brain tumor risk, but there are no proven associations so far. “The biggest risk of cell phone use is being in a car accident,” Dr. Sloan says. “If you are on the phone while driving, there is known to be a four-fold increased risk.”
If you are concerned that you may be at risk for spinal cord or brain tumors, talk with your doctor. Together, you can look at your medical history, talk about the possible risk factors, and determine a course of action.