by Lyons S

Glioblastoma Multiforme

(GBM; Brain Tumor; Malignant Astrocytoma)


Glioblastoma multiforme (GBM) is the most common glioma—a type of brain cancer. This cancer starts in the glial cells, which are cells that help nerve cells work.
This condition can develop suddenly. It can also develop from a lower-grade, less cancerous brain tumor. Most cases are located in the cerebral hemisphere of the brain. The cancer can also begin in the spinal cord or brain stem.
Brain Tumor
Nucleus Image
Copyright © Nucleus Medical Media, Inc.


GBM originates from astrocytes, which are a type of glial cell. The factors that cause normal-functioning astrocytes to become cancerous is not well understood.

Risk Factors

GBM is more common in people over 50 years old, especially those who are Caucasian, Hispanic, and Asian. Factors that increase your chance of developing GBM include:
  • Having a low-grade brain tumor, which occasionally develops into a higher-grade tumor
  • Having one of the following genetic disorders:
  • History of radiation therapy
  • Occupational exposures in the synthetic rubber or petroleum-refining industries
  • Exposure to vinyl chloride or pesticides
  • History of CT scans during childhood


Symptoms may vary depending on the location or size of the tumor. In general, symptoms may include:
  • New onset headaches
  • New onset seizures
  • Progressive cognitive dysfunction
  • Problems with vision, language, motor function, or sensation may occur
  • Progressive neurological deficits, including weakness or numbness
  • Personality changes
  • Behavioral changes, development of inappropriate behaviors
  • Memory loss


You will be asked about your symptoms and medical history. A physical exam will be done.
Images and scans may be taken of your brain. This can be done with:
Your brain activity may be measured. This can be done with:
Your bodily fluids and tissues may be tested. This can be done with:
  • Biopsy—tissue samples are taken and examined under a microscope
  • Lumbar puncture—to evaluate the cerebrospinal fluid that surrounds the brain and spinal cord


Surgery is often done to confirm diagnosis and relieve headache, but doctors cannot completely remove the cancer. Other types of treatment may include:
  • Radiation therapy—to further decrease the size of the tumor
  • Chemotherapy—to increase survival time and quality of life
  • Steroids to suppress swelling
  • Antiseizure medications to suppress seizures
  • Pain relievers
Even with aggressive treatment, few patients survive more than 5 years after diagnosis. However, there is evidence that medical and surgical intervention can increase life expectancy and improve quality of life.
A multi-disciplinary approach is important for you and your family. This approach may involve:
  • Support groups
  • Psychotherapy and psychiatry
  • Pain management
  • Hospice care


There are no current guidelines to prevent GBM because the cause is unknown.


American Brain Tumor Association
National Brain Tumor Society


Brain Tumour Foundation of Canada
Canadian Cancer Society


General information about adult primary central nervous system (CNS) tumors. National Cancer Institute website. Available at: Updated January 27, 2016. Accessed September 6, 2016.
Glioblastoma. EBSCO DynaMed Plus website. Available at: Updated May 16, 2016. Accessed September 26, 2016.

Revision Information

Health Library Search

Only show results from the selected categories.

2 Meningioma condition

The meninges are a protective lining around the brain and spinal cord. A meningioma is a tumor of these linings. Most meningiomas do not cause symptoms. But, if the menin...

3 Treatments for Brain Tumors condition indepth
6 Symptoms of Brain Tumors condition indepth
8 Screening for Brain Tumors condition indepth
14 Medications for Brain Tumors condition indepth
17 Diagnosis of Brain Tumors condition indepth
18 Astrocytoma condition

Astrocytoma is type of cancerous brain tumor. This type of tumor begins from small, star-shaped cells in the brain called astrocytes. Astrocytes are one of several types ...

19 Medulloblastoma condition

Medulloblastoma is a type of brain cancer. It starts in an area known as the cerebellum, at the bottom and back of the brain. The cerebellum is the center for balance, c...

A brain tumor is the presence of cancerous cells in the brain. There are 2 types of brain tumors....