Glioma is not a specific type of brain cancer but refers to a group of tumors that start in the brain's glial cells. Several types of tumors are classified as gliomas. These range from low-grade and relatively treatable to high-grade, very serious, tumors with poor outcomes. About 30 percent of all brain tumors are gliomas and 80 percent of malignant brain tumors are gliomas. They are uncommon in children, and their incidence rate goes up with age.
The three basic types of glioma are:
There are very few obvious risk factors associated with brain tumors, therefore they are difficult to prevent. Radiation exposure, most commonly due to radiation therapy used to treat other cancers, can increase a person's risk for brain tumors. Most people with brain tumors do not have a family history of the disease. However, brain and spinal cord cancers run in families of people with rare diseases like Neurofibromatosis, tuberous sclerosis and other inherited genetic conditions. People with impaired immune systems also may be at increased risk. Currently, there are no blood or other screening tests that can reliably detect brain tumors at an early stage.
Symptoms of brain or spinal cord tumors can be fairly general, with specific symptoms depending on the exact location of the tumor. Symptoms may occur gradually and become worse over time, or they can happen suddenly, as with a seizure. Any tumor in the brain may cause increased pressure or swelling, leading to complaints of headaches, nausea, vomiting, blurred vision, weakness or numbness, coordination or balance problems, speech or comprehension difficulties, personality or behavior changes, seizures, and drowsiness. All of those symptoms can also be caused by other conditions and do not necessarily indicate a brain tumor. Any concerns should be followed-up with a neurologic exam to evaluate brain and spinal cord function.
Survival is very specific to the type of glioma and is most often determined by a person's age, the type of tumor, its size and location, whether it can be surgically removed and how far it has spread. In general, younger people (under 45) have significantly better survival rates than those over 55 and those diagnosed with lower grade gliomas face better chances than those with aggressive tumors.
Some gliomas can be surgically removed or reduced, while others will be treated with a combination of radiation and chemotherapy, which can help prevent or relieve symptoms. Researchers are continually working on clinical trials and targeted therapies to better understand the formation of brain tumors and improve treatment.'