Overview
The glioblastoma multiforme is the most common type of glioma tumor of the brain. The presentation for a glioblastoma is typically the same as other brain tumors. Glioblastomas have a poor prognosis and do not typically respond well to current treatment. Biospy of the brain mass is the best way for physicians to determine if the tumor is in fact a glioblastoma.
Risk Factors
According to a 2009 study by Northwestern University researcher Dr. Ajay Yadav, there is about a 75 percent incidence of a deletion on chromosome 10 in the ANXA7 gene in glioblastoma patients. Other risk factors include exposure to vinyl chloride or pesticides, therapeutic ionizing radiation and exposure to the production of rubber or petroleum. Some possible risk factors may be smoking and cell phone use, but these need to be further researched. Exposures to filtered cigarettes, diagnostic radiation and formaldehyde are not associated with an increased risk.
Symptoms
Symptoms of a glioblastoma are similar to symptoms of any other primary brain tumor. Patients often complain of persistent headache, seizures, nausea, vomiting, neurocognitive symptoms and personality changes. The symptoms tend to occur as the tumor is increasing in size.
Making the Diagnosis
Patients typically present with either a chronic headache, progressive mental status, neurologic deficit or personality change, or seizure, according to a 2008 article in “American Family Physician.” An incidentaloma is often the cause of finding the glioblastoma. The term “incidentaloma: refers to an incidental finding of a tumor on a imaging study that was ordered for another reason.
Physical exam may reveal a neurological deficit or motor weakness. The exam findings will typically correlate with the part of the brain where the tumor is located or where there is compression.
Imaging
Radiographic imaging is the best method to determine if there is a mass in the brain. CT scan with contrast may allow for radiology to distinguish glioblastoma from other tumors. An MRI can be used to help better classify a brain mass. Positron emission tomography (PET) can be used to assess the metabolic rate of tumors and can be helpful to monitor the mass post-chemotherapy or post-radiation.
Stereotactic Biopsy
A stereotactic biopsy will provide a specimen for a pathologist to classify using the microscope and special stains. The biopsy is performed using MRI or CT to help guide the physician while taking a tissue specimen.
Treatment
Treatment for glioblastoma multiforme consists of extensive tumor resection, radiation therapy and chemotherapy. Neurosurgical resection should be as extensive as possible to remove as much tumor as possible. Radiation therapy is considered a standard of care, although it may modestly improve survival. A carmustine wafer can be placed in the skull and supply direct medication to the tumor. This is associated with increased survival. Corticosteroids such as dexamethasone can reduce tumor size. This may be helpful if the size of the tumor creates compression on neurologic structures causing symptoms.
Chemotherapy is used as an adjunct to radiotherapy. The specific form of chemotherapy given is based on the decision of an oncologist.
Prognosis
Unfortunately, the prognosis for glioblastoma is very poor. There is approximately a 3 percent five-year survival. One year survival is less than 30 percent for glioblastoma. Patients who do not have a noticeable tumor after treatment do have a longer median survival.
About this Author
Gregory Waryasz is a graduate of Boston College and an M.D. candidate for May 2010 at Tufts University School of Medicine. He will be starting an orthopaedic residency at Brown University/Rhode Island Hospital in June of 2010. He is certified as a strength and conditioning specialist (CSCS) through the NSCA.
