What causes brain tumors?


Brain tumors form like other types of tumors. Abnormal cells grow and multiply, sometimes very rapidly, into an abnormal mass of tissue.

Tumors that form from the tissues of the brain are called primary tumors. These tumors can be ‘glial,’ meaning they are formed from the brain’s glial cells, or non-glial, which means they have developed on or in the structures of the brain like the nerves, blood vessels and glands. Primary tumors can be benign, which means they are non-cancerous and don’t spread to other parts of the body, or malignant, which means they are cancerous and can spread through the body. Benign can also refer to tumors that grow slower and malignant can also refer to tumors that grow and recur quickly.

In addition to primary tumors, there are metastatic tumors. These tumors include those that start somewhere else in the body, like the breast or the lungs, and ‘migrate’ or spread to the brain, usually through the bloodstream. These tumors are considered malignant or cancerous growths. In the USA alone, metastatic tumors in the brain affect nearly one in four patients with cancer and up to 40% of people with lung cancer will develop metastatic brain tumors.1 Advancements in early diagnosis and innovative medical technologies, like image guided surgery, are improving survival rates and quality of life for patients, helping them live longer, fuller lives with better control of their brain metastases.

1 American Association of Neurological Surgeons