Brain Tumors
Brain tumors are growths of tissue that form when abnormal cells in the brain divide and duplicate out of control. Brain tumors may be benign (noncancerous) or malignant (cancerous).
Even though benign brain tumors do not spread like cancerous brain tumors, they can press on areas of the brain and cause serious health issues.
About Brain Tumors
There are two types of brain tumors:
- Primary brain tumors: Tumors that originate in the brain.
- Secondary brain tumors: Tumors that form from cancer cells that have spread to the brain from another part of the body. Secondary tumors are much more common in adults than primary brain tumors.
Brain tumors are given a grade between I and IV. Grade I tumors are benign and slow-growing. Cells in grade IV tumors are malignant and grow quickly.
Primary Brain Tumors
Primary brain tumors begin in the cells in the brain. These tumors can grow and invade other tissues of the brain, but unlike other cancers, primary brain tumors rarely spread to other parts of the body.
There are many types of primary brain tumors. Some of the most common in adults are:
- Gliomas: This is a primary brain tumor that begins in glial cells. Most gliomas develop in glial cells called astrocytes. These brain tumors are called astrocytomas, and they are difficult to remove entirely with surgery because they can spread widely throughout the brain. Less common types of gliomas include brain stem glioma, ependymoma and oligodendroglioma.
- Meningioma: A type of brain tumor that begins in the layers of tissue that surround the outer part of the brain and spinal cord, called the meninges.
- Medulloblastoma: This tumor usually develops in the cerebellum, an area at the back of the brain that controls balance and actions like walking and talking. This is the most common brain tumor in children.
- Schwannoma: This tumor (usually benign) begins in the Schwann cells that line the nerve that controls balance and hearing.
Who’s at Risk?
Each year in the U.S., more than 35,000 people are diagnosed with a brain tumor. Brain tumors are found more often in men than women, and they are the second most common cancer in children. People after the age of 70 are at a higher risk than other adults.
Risk Factors
Studies have found the following risk factors to increase the chance of developing a brain tumor:
- Radiation: Exposure to high-dose radiation given from x-rays to the head in radiation therapy.
- Family history: Family members who have gliomas. Some rare inherited conditions also increase the chance of brain tumors.
Treatment
Surgery is usually performed to remove all or part of the brain tumor. If surgery is not possible, several methods of radiation therapy may be used to kill the cancerous cells. Gamma Knife is a form of radiation therapy that uses precisely targeted radiation beams to destroy brain tumors.
Chemotherapy may also be part of the treatment plan.
Some information on this page is provided by the National Cancer Institute and the American Cancer Society.