Glioma is a specific and highly dangerous form of cancer which arises in the glial cells, glue-like cells which occur between neurons in the brain and spine. It is quite uncommon, with only about 10,000 cases occurring in the United States each year. Tragically, it is also highly lethal, with a 50% survival rate after one year and 25% after two years. Although the disease can be treated aggressively, so far these treatments are seldom effective over the long term. Such well-known people as senator Ted Kennedy and journalist Robert Novak have died after developing glioma.
– About Glioma –
According to the Society for Neuroscience, glioma is an especially aggressive and devastating type of brain tumour because of the speed with which it invades and kills surrounding and previously healthy areas of the brain. In other areas of the body, tumours simply grow by “pushing healthy cells aside.” However, in the brain this is not possible (brain swelling under normal conditions results in headaches), so the glioma opts for the more direct route of killing nearby cells with an overdose of a compound called glutamate, usually used in much smaller amounts as a neurotransmitter. Unlike most cancers, which spread throughout the body via the blood, gliomas spread throughout the brain and spinal cord via a clear fluid called cerebrospinal fluid.
There are four specific types of glioma, differentiated based upon the apparent type of cells which the tumour is made up of: ependymoma, astrocytoma, glioblastoma, and oligodendroglioma. The third of these, glioblastoma multiforme, is often associated with the worst (that is, deadliest) prognosis. Physicians then subdivide glioma into two additional categories, benign or low-grade and malignant or high-grade. Malignant gliomas are aggressive, invasive tumours and pose the greatest risk to a cancer victim. Low-grade gliomas, by contrast, grow over a period of multiple years and may not even require treatment except to handle their size and any associated symptoms.
– Symptoms –
Glioma typically causes a range of symptoms affecting the functioning of the central nervous system. These can include headaches (the most common and prevalent symptom of brain tumours), seizures, digestive problems like nausea, and nerve problems resulting from growth and therefore high pressure upon healthy tissues within the brain. Other symptoms may result depending upon the particular location of the glioma: for example, if it affects those areas of the nervous system associated with movement and sensation (such as the spinal cord), sufferers may experience resulting pain, loss of sensation, or apparent muscular weakness in their arms or legs.
As with most types of cancer, it must be remembered that many of these symptoms are common to a wide variety of ailments, most of them not at all life-threatening. A qualified physician, usually a neurologist, can make a diagnosis of glioma after appropriate diagnostic tests, which may include an MRI, a CT scan, and/or head X-rays, followed by a biopsy of the suspicious growth to confirm the presence of cancer.
– Treatment –
Glioma, like all cancers, may be treated through some combination of physical removal of the primary tumour (i.e. surgery), radiation treatment, and chemotherapy. Wherever possible, the Mayo Clinic prefers to attack the disease first via surgery; even where they cannot fully remove the glioma, it is sometimes possible to reduce harmful pressure within the skull as well as reduce the total amount of cancerous material which must be targeted by the next two waves of cancer treatment, radiation and drug therapy. One common drug used in the treatment of aggressive glioma is temozolomide, marketed as Temodar or Temodal.
To date, a single set of highly effective treatment regimens for glioma has not yet been identified. However, medical research continues on several fronts.
– Further Reading –
Mayo Clinic. “Glioma.”
Society for Neuroscience. “Glioma Brain Tumors.”
