GBM F.A.Q.
What is Glioblastoma Multiforme?
(GLEE-oh-blas-TOH-muh MUL-tih-form) - Glioblastoma Multiforme (GBM) is a primary form of brain cancer. This means that it is a cancer that originates from cells that make up the tissues of the brain. Specifically, GBM is a cancer that originates from astrocytes, a sub-type of glial cells, making it a glioma and an astrocytoma.
Is it a brain tumor?
Yes, GBM is a malignant brain tumor. A tumor is a mass of extra cells that a physical body does not need. A malignant tumor contains cancer cells whereas a benign tumor does not. Malignant tumors tend to grow much more rapidly than benign tumors and are more invasive to the healthy tissue surrounding it.
What is a glioma or astrocytoma?
A glioma is a primary type of central nervous system tumor that arises from glial cells. The central nervous system consists of the brain and spinal cord. Likewise, an astrocytoma is a tumor that has arisen from the more specific type of glial cells, astrocytes.
What is a glial cell?
Glial cells get there name from the greek word glia (meaning "glue"). Glial cells are one of two major types of cells within the central nervous system; the other type are neuron cells. Glial cells provide support, nutrition, and protection to the neurons, among other functions. Glial cells outnumber nuerons by about 10 to 1.
What is an astrocyte?
Astrocytes are named after their star-shaped cell structure. They are a sub-type of the glial cells. The many arms that define their star-shape span all around nuerons. They are known to form the blood- brain barrier, provide nutrients, and play a principal role in the repair and scarring process of the brain.
What does "high grade" or "grade IV" mean?
The World Health Organization has a grading system used to define tumors that behave differently, but originate from the same type of cell. GBM is defined as a grade IV astrocytoma. Grade I is the most benign, while grade IV is the most malignant.
What are some symptoms of Glioblastoma Multiforme?
Symptoms depend highly upon the location of the tumor. The location of a tumor will vary from person to person. For example, a tumor near the sensory-motor strip will impact a persons ability to move and/or feel parts of their body. In contrast, a tumor near the optic portion of the brain will affect the brain's ability to process signals from the eyes causing blurred vision or blindness. A person's memory or personality can be affected too if the tumor involves the temporal or frontal lobes. However, some symptoms are common in every tumor due to increased intracranial pressure. These include seizure, nausea and vomiting, headache, and partial paralysis. Typically, symptoms do not present themselves until a tumor is very large.
What are the standard treatments of GBM?
The first option explored is surgery. Surgery is the best means to remove a tumor. Of course, removing tumor implies that parts of a person's brain will be removed as well. Brain surgery is difficult enough, but the shape of a GBM is an added challenge. GBMs tend to grow "fingers" that writhe between the folds of the brain. A neurosurgeon and his team will have to decide between the tradeoffs of removed-tumor versus removed-brain, prognosis, and quality of life. Some parts of the brain are too risky to tamper with.
Surgery is very effective, but even if 100% of the tumor is removed more must be done. GBM is not confined to an encapsulated mass, but has microscopic cells that invade the surrounding area of the tumor as well. Following surgery it is common the undergo chemotherapy concurrent with radiation therapy. Both a medical oncologist and radiation oncologist will work together on a treatment plan.
The most effective form of chemotherapy known at the moment is temozolomide that is administered under the brand names of Temodar and Temodal. Before other chemo-agents are considered, a medical oncologist will typically observe how a patient responds the the temozolomide.
At the same time radiation will be given to attack the tumor site directly and increase the effectiveness of the chemotherapy. It is common to receive whole brain radiation in addition to a boost of radiation to the known tumor location. Whole brain radiation is used as an attempt to kill any microscopic tumor cells that exist beyond the main tumor mass. Radiation is usually given over a course of 6 weeks.
Can Glioblastoma Multiforme metastasize?
The occurrence of a metastasis (spreading of the cancer from one part of the body to another) is very rare, but it can happen. GBM cells do not really travel in the blood stream, but rather in cerebrospinal fluid. Therefore it is much more common to see new tumors form at new locations within the brain or even sometimes on the spinal cord.