Glioblastoma Multiforme, also known as a GBM or grade IV astrocytoma, is the most common and malignant type of tumors originating in the brain (also known as primary brain tumors). While glioblastoma multiforme tumors can occur anywhere in the brain, their tendency to spread aggressively and create “satellite tumors” in other areas of the brain makes them difficult to treat.
While a definitive cause is unknown, glioblastoma multiformes are believed to be the result of genetic mutations that result in the uncontrollable growth of specific types of brain cells. They tumors make up 19 percent of all primary brain tumors and while the average age of diagnosis is 55 years old, glioblastoma multiforme tumors can be diagnosed at nearly any age. Gliomas are also slightly more common in men and in Caucasians than in any other ethnicity.
The risk of developing a glioma increases if a person has any of the following genetic disorders: Neurofibromatosis, Tuberous sclerosis, Von Hippel-Lindau disease, Li-Fraumeni syndrome and Turcot syndrome.
Diagnosing A Glioblastima Multiforme
Imaging studies performed by a brain specialist (also known as neurologist) are the most effective way to locate and diagnose a glioblastoma multiforme. They can include an MRI (Magnetic Resonance Imaging), CT Scan (Computed Tomography) and chest X-Ray. A biopsy – or piece or tissue removed from the tumor itself – may also be necessary to determine the type of tumor.
• MRI (Magnetic Resonance Imaging): A non-invasive scan that reveals detailed images of the brain and its surrounding nerves and tissue.
• CT Scan (Computed Tomography): While a surefire diagnosis comes from an MRI, a CT scan can also help identify the exact location and size of the tumor. A CT scan uses X-rays to make detailed images of structures inside the body.
• Chest X-Ray: A chest X-ray may be taken to see if the tumor has spread – or metastasized – from the brain to other parts of the body (or vice versa). However, X-rays are much less sensitive and are used less often to diagnose a brain tumor.
Brain tumors are categorized on four-level scale developed by the World Health Organization. Grade I tumors are the least aggressive, while Grade IV are the most aggressive. Glioblastoma Multiforme are Grade IV tumors.
• Grade I: These tumors have slow-growing cells that appear similar to normal brain cells.
• Grade II: Cells of Grade II tumors grow relatively slowly but show signs of change. They are typically considered “pre-cancerous,” as the tumor’s cells may begin to move into neighboring healthy brain tissue. If they are surgically removed, the tumor may return as a higher-grade.
• Grade III: The cells of Grade III tumors lack the structure and function of normal cells. They actively reproduce and can grow into neighboring healthy tissue. Again, if they are surgically removed it is not uncommon for the tumor to return as a higher-grade.
• Grade IV: Grade IV tumors are made up of the most aggressive, rapidly reproducing abnormal cells. These cells reproduce so quickly because they are able to form new blood vessels that support their aggressive growth.
Treatment & Risks
Although length of survival has historically been limited, especially among patients suffering from the most aggressive gliomas, it is important to remember that some patients live considerably longer than statistics suggest. Cedars-Sinai scientists are taking a proactive approach in fighting these tumors and have developed innovative, experimental approaches to treatment. Several clinical trials are now underway.
Since every patient and tumor is unique, Cedars-Sinai develops a customized team that may include one or more of the following specialists:
• Neuro-oncologist: A physician specializing in brain cancer.
• Neuropathologist: A physician specializing in diseases of the brain and spinal cord with the ability to make a definitive diagnosis of brain tumors.
• Neurosurgeon: A physician trained in surgery on the nervous system, especially the spine and the brain.
• Radiation oncologist: A physician specializing in the treatment of cancer patients, using radiation therapy as the main method of treatment.
Due to the aggressive nature of glioblastoma multiformes, the tumors are typically treated by two methods: immediate surgical removal (if and when possible) followed by a treatment of chemotherapy and/or radiation. If surgery is not an option, it may be that a patient is not healthy enough to undergo surgery; the tumor is situated in an inaccessible location; or the tumor spread so extensively that surgery is no longer possible.
1. Surgery: The goal of surgery is to remove as much of the tumor as possible while minimizing damage to healthy brain tissue. The location and size of the tumor will determine how much of it, if any, can be removed. Removal of the tumor reduces the pressure within the brain, improving symptoms. If the entire tumor cannot be removed, the smaller, remaining area will be treated by radiation. Even after the most successful of surgeries, it is possible that microscopic tumor cells remain and may re-grow. However, overall treatment effectiveness and length of survival are generally found to be better when “image-complete resection” (the complete removal of all tumor cells visible on MRI) occurs.
2. Radiation: In certain situations, complete surgical removal of the tumor may not be an option. For example, the neurosurgical team may need to leave part of the tumor in place to avoid damage to a vital structure and the possibility of serious or life-threatening consequences. In these cases radiation may be an appropriate treatment, either alone or following surgery. Cedars-Sinai’s treatment teams have several state-of-the-art focused radiation options. For glioblastoma multiforme tumors, the Gamma Knife® is an extremely precise, fixed system that uses up to 201 separate beams of radiation converging at a single point. The Trilogy™ System provides highly focused, image-guided radiotherapy and radiosurgery for treating glioblastoma multiformes and other lesions that are in close proximity to the spinal cord or other vital structures. The goal of either approach is to bombard the tumor with a destructive dose of radiation while minimizing damage to healthy tissue.
Specific symptoms of a glioblastoma multiforme depend on the size and location of the tumor, but can develop quickly and unexpectedly.
Common symptoms include:
• Nausea and/or vomiting
• Weakness on one side of the body (also known as hemiparesis)
• Progressive personality or neurological changes
• Memory or word loss