Definition

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.

Causes

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 chances 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:
  • Neurofibromatosis
  • Tuberous sclerosis
  • Von Hippel-Lindau disease
  • Li-Fraumeni syndrome
  • Turcot’s syndrome
• Having had radiotherapy
• Working in the synthetic rubber or petroleum refining industries
• Exposure to vinyl chloride or pesticides
• Having had CT scans during childhood

Symptoms

Symptoms include:

• New onset headaches
• New onset seizures
• Progressive cognitive dysfunction—depends on the location of the tumor; problems with vision, language, motor function, or sensation may occur
• Progressive neurological deficits, including weakness
• Personality changes
• Behavioral changes, development of inappropriate behaviors
• Memory loss

Diagnosis

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:

• CT scan
• MRI scan
• Functional MRI (fMRI)
• Positron emission tomography (PET) scan

Your brain activity may be measured. This can be done with:

• Magnetic resonance spectroscopy (MRS) scan
• Electroencephalogram (EEG)

Your bodily fluids and tissues may be tested. This can be done with:

• Tumor biopsy
• Spinal tap

Treatment

Surgery is often done to confirm diagnosis and relieve headache, but doctors cannot completely remove the cancer. Other types of treatment may include:

• Radiation treatment is used to further decrease the size of the tumor.
• Chemotherapy is used to increase survival time and quality of life.
• Steroids to suppress swelling, antiseizure medication to suppress seizures, and pain medications are also used.

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 group
• Psychotherapy and psychiatry
• Pain management
• Hospice care

Prevention

As the causes of GBM are unknown, there are no preventive measures.

National Brain Tumor Society http://www.braintumor.org

Canadian Cancer Society http://www.cancer.ca

Glioblastoma. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated March 30, 2015. Accessed June 11, 2015.