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Glioblastoma Multiforme (GBM)

What is Glioblastoma Multiforme?

Glioblastoma, also called glioblastoma multiforme (GBM), is a Grade 4 malignant astrocytoma that begins in the brain. Among brain cancers, GBM is the most common in adults, the most lethal, and the hardest to treat. GBM can create its own supply of blood, enabling it to grow and spread very quickly to other parts of the brain. The five-year survival rate for GBM is about 15%. Although GBM rarely metastasizes outside the central nervous system, it moves easily through neural tissue.

Glioblastoma most often appears in the largest part of the brain, called the cerebrum; however, it can occur in other areas as well. Treatment can be difficult, and is generally designed to slow the tumor’s growth and minimize its effects.

What You Can Expect at UTHealth Houston Neurosciences

At UTHealth Houston Neurosciences, neurologists, neurosurgeons, interventional pain management specialists, neuro-oncologists, radiation oncologists, and neuropathologists work together to determine the care each patient needs, discussing treatment options as a group. This approach saves our patients time and money and allows our specialists to share each other’s insights, leading to better treatment decision-making and outcomes.

Our neurosurgeons routinely employ innovative minimally invasive techniques. Throughout the treatment process, our team works closely with the doctor who referred you to ensure a smooth transition back to your regular care plan. While you are with us, you can expect expert care, excellent communication, and genuine compassion.

Causes of Glioblastoma

Doctors and researchers do not know what causes glioblastoma, although they do know that past radiation to the central nervous system or head increases the lifetime risk of developing glioblastoma. Some research has shown that seasonal allergies, such as hay fever, may have a protective effect, possibly through a heightened immune system.

Early Signs of Glioblastoma and Diagnosis

GBM tends to occur in active, otherwise healthy people, and more frequently in men. Symptoms may be sudden and acute, or there may be gradual changes. They include headaches, weakness or difficulties with coordination on one side of the body, memory problems, mood or personality changes, loss of appetite, nausea and/or vomiting, seizures, double or blurred vision, drowsiness, difficulty thinking and speaking, and problems with concentration.

Glioblastoma is diagnosed using CT scans or MRI. Magnetic resonance spectroscopy is used to examine the tumor’s chemical profile, and positron emission tomography can detect recurrence of the tumor.


The standard of care for GBM is surgery to remove as much of the tumor as possible without injuring normal brain tissue, followed by radiation and chemotherapy. Because glioblastoma is infiltrating tumor cells quickly invade surrounding tissues, the goal of surgery is to remove the cells in the center of the tumor that may resist radiation and chemotherapy. Treatment is focused on prolonging life and improving the quality of remaining life.

Neurosurgeons usually perform a craniotomy, opening the skull to reach the tumor site. Intra-operative mapping techniques determine the locations of the motor, sensory, and speech-language cortex to protect these regions during surgery. Radiation therapy begins after the surgical site has healed. Gamma Knife® radiosurgery may be used to treat tumor recurrence.

Most patients who undergo chemotherapy receive the drug temozolomide, the current standard treatment for GBM. The drug is given every day during radiation therapy and then for six to 12 28-day cycles after radiation. Other types of chemotherapy may be given for tumor recurrence.


The standard course of cancer treatment – surgery, radiation therapy, and chemotherapy – has been minimally effective in treating GBM. A high percentage of people with glioblastoma have difficulty returning to work and their daily routines and rely on the help of their families and close friends. In the mid-1990s the median survival after a diagnosis of GBM was eight to 10 months, and no patients survived five years after their diagnosis. Since then it has doubled to 15 to 18 months, and 15% of people with GBM survive five years.

Many GBM patients qualify to participate in clinical trials testing treatments and combinations of treatments, as researchers search for the most effective and least toxic treatments. Improvement in outcomes have been small, but researchers at UTHealth Houston Neurosciences and other institutions are working together to better understand the disease mechanisms of GBM and develop more effective treatments. Researchers at UTHealth Houston Neurosciences are also discovering new and more effective ways to penetrate the blood-brain barrier to ensure that chemotherapeutic drugs reach specific targets in the brain. Ask your treatment team about clinical trials underway for GBM.

Clinical Trials

Learn more about our clinical trials for Glioblastoma Multiforme (GBM) here »

Brain Tumor Types

Acoustic neuroma
Arachnoid Cyst
Brain metastases
Choroid plexus tumor
Facts about brain tumors
Gamma Knife Radiosurgery
Germ cell tumor
Glioblastoma Multiforme (GBM)
Malignant meningioma
Pituitary adenoma and Cushing’s syndrome
Pituitary tumor
Skull base tumor

Contact Us

At UTHealth Houston Neurosciences, we offer patients access to specialized neurological care at clinics across the greater Houston area. To ask us a question, schedule an appointment, or learn more about us, please call (713) 486-8000, or click below to send us a message. In the event of an emergency, call 911 or go to the nearest Emergency Room.