Brain cancer causes and risk factors

This page was reviewed under our medical and editorial policy by

Maurie Markman, MD, President, Medicine & Science

This page was updated on June 8, 2022.

Risk factors for brain cancer may vary. The risk for developing primary brain cancer is very low. The American Cancer Society estimates the risk over a lifetime is less than 1 percent.

What causes brain cancer?

The cause of brain cancer is still largely unknown. Although some genetic conditions and environmental factors may contribute to the development of brain cancer, the risk factors are much less defined for brain cancer than for other cancers in the body.

It’s important to remember that a brain cancer risk factor only affects the probability of developing brain cancer over a lifetime. For example, if a patient has received radiation therapy to treat another cancer, or if he or she has worked in an industry handling potentially cancerous chemicals, he or she may want to discuss with a doctor what it means in terms of his or her individual risk for developing brain cancer.

There is no definitive cause of primary brain tumors or brain cancer. Secondary brain tumors, or brain metastases, are cancers that originate in other parts of the body and spread to the brain. They are far more common than primary brain tumors. Risk factor for secondary brain cancers depend on where the cancer originated. The most common primary cancers that spread to the brain include breast, lung, kidney, colorectal and melanoma.

Brain cancer risk factors

Gender: Certain cancers, like meningiomas, are twice as likely to develop in women, while medulloblastomas are more frequently found in males.

Age: The frequency of brain cancer increases with age, with more occurrences in individuals age 65 and older. The age factor varies depending on the cell type and location of the tumor. Adults have a very low risk of developing medulloblastomas, while gliomas are most common in adults. The incidence of meningiomas and craniopharyngiomas are far more frequent in adults over age 50, but again, these tumors may occur at any age.

Compromised immune system: Some people with compromised immune systems have an increased risk of developing lymphomas of the brain.

Genetic links: Family history may affect the likelihood of developing certain diseases. Von Hippel-Lindau disease, Li-Fraumeni syndrome and Neurofibromatosis (NF1 and NF2) are inherited conditions that have been found in families with a history of rare brain tumors. Otherwise, there is little evidence that brain cancer runs in families.

Learn more about genetic counseling and genetic testing

Chemical exposure: Exposure to certain industrial chemicals or solvents has been linked to an increased risk in developing brain cancer. Although it is not conclusive, evidence has found a higher incidence of certain types of brain tumors in individuals who work in oil refining, rubber manufacturing and drug manufacturing.

Previous radiation treatment: Exposure to radiation therapy, particularly at a young age, may increase the likelihood of developing brain cancer.

Next topic: What are the symptoms of brain cancer?

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