Brain tumor risk factors: what raises the risk

What a brain tumor is

A brain tumor is a growth of abnormal cells in the tissues of the brain. It can be benign, with no cancer cells, or malignant, with cancer cells that grow quickly (MedlinePlus). Primary tumors start in the brain or spinal cord. Secondary (metastatic) tumors start somewhere else in the body and travel there; they are more common than primary tumors and happen more often in adults than in children (NINDS).

There are more than 120 types of brain and spinal cord tumors. Gliomas are the most common type of brain tumor, and meningiomas, which grow from the membranes around the brain, are usually benign and slow growing (NINDS).

Who is more likely to get a brain tumor

Anyone can develop a primary brain or spinal cord tumor, but NINDS says the overall risk is very small (NINDS). NCI notes there are few known risk factors, that not everyone with a risk factor gets a tumor, and that tumors can develop in people with no known risk factor (NCI PDQ). The factors the sources name are:

• Age. Among people who develop these tumors, they are most common in older adults. In children they are uncommon, but most often happen under age 9, and brain tumors are the leading cause of cancer deaths in children (NINDS).
• Race and sex. NINDS gives White men as an example of a group more likely to develop a primary tumor (NINDS).
• Radiation and chemicals at work. Jobs with repeated contact with ionizing radiation or certain chemicals, including materials used in building supplies, plastics and textiles, carry a greater chance of a brain tumor (NINDS). NCI says exposure to vinyl chloride may raise the risk of glioma (NCI PDQ).
• Genetic syndromes. NCI lists neurofibromatosis type 1 or 2, von Hippel-Lindau disease, tuberous sclerosis, Li-Fraumeni syndrome, Turcot syndrome type 1 or 2, and nevoid basal cell carcinoma syndrome (NCI PDQ). NINDS adds that some of these conditions run in families (NINDS).
• A weakened immune system. Epstein-Barr virus infection, AIDS or an organ transplant may raise the risk of primary central nervous system lymphoma (NCI PDQ). NINDS lists viral infections and immune system disorders among the possible causes researchers are studying (NINDS).

The cause of most adult brain and spinal cord tumors is not known (NCI PDQ). See lymphoma risk factors for more on immune-related cancers. NINDS lists brain tumors among the conditions that can lead to epilepsy (NINDS); see epilepsy risk factors.

Symptoms to know

Symptoms depend on where the tumor is, its size, how fast it grows and its type. Headaches are the most common symptom (NINDS). MedlinePlus lists these as some of the most common (MedlinePlus):

• headaches, often in the morning
• nausea and vomiting
• changes in your ability to talk, hear or see
• problems with balance or walking
• problems with thinking or memory
• feeling weak or sleepy
• changes in mood or behavior
• seizures

NINDS adds that a seizure starting in adulthood with no known cause is a sign to take seriously, and that in babies the most obvious sign is a quickly widening head or swelling around the soft spot (NINDS). Many of these symptoms have other, more common causes.

How brain tumors are found and treated

A doctor reviews medical and family history and does physical and neurological exams. MRI is the main imaging test, and a biopsy may be done (NINDS). Treatment options include watchful waiting, surgery, radiation therapy, chemotherapy and targeted therapy, and many people get a combination (MedlinePlus).

Common questions

Do cell phones cause brain tumors?

NCI says the evidence to date suggests that cell phone use does not cause brain or other kinds of cancer in humans. Phones give off non-ionizing radiofrequency energy, which is too low in energy to damage DNA, unlike ionizing radiation such as x-rays (NCI).

Are brain tumors genetic?

Most are not linked to a known cause, but some inherited syndromes, such as neurofibromatosis and Li-Fraumeni syndrome, raise the risk (NCI PDQ). If one of these runs in your family, ask your clinician about genetic counseling. Li-Fraumeni syndrome also comes up in leukemia risk factors.

Which risk factors can I change?

Age, sex and inherited syndromes cannot be changed. NINDS links repeated work contact with ionizing radiation or certain chemicals to a higher chance of a brain tumor (NINDS), and NCI notes that exposure to vinyl chloride may raise the risk of glioma (NCI PDQ). If your job involves these, ask about workplace protections.

Is there a brain tumor risk calculator?

No. The sources on this page do not offer a validated score for the general public, so we do not provide one.