Glioblastoma (also known as glioblastoma multiforme) is a type of fast-growing brain tumor and the most common malignant primary brain tumor in adults. Most primary tumors that develop in the brain start in glial cells (supporting cells of the brain), called astrocytes; the tumors are known as astrocytomas. Glioblastomas are the highest-grade or most aggressive of those.
Brain tumors, unlike other cancers, almost never spread to other organs. However, they often spread – finger-like – to other parts of the brain or central nervous system. Survival 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. Even non-cancerous tumors can lead to serious complications of brain function, unless removed. It is important to note, in adults, metastatic brain tumors (that spread to the brain from another organ) are actually more common than primary brain tumors, and require different treatment.
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. 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. Specific symptoms depend 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 and 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.
Unfortunately, glioblastoma is a very serious condition, and the prognosis for the majority of patients remains poor. The Central Brain Tumor Registry of the United States (CBTRUS) puts 5-year survival rates for patients aged 55-64, treated between 1995 and 2007, at approximately 3 percent; this number rises to 16 percent for patients aged 20-44.
Glioblastomas are not usually cured by surgery. But surgery can ease symptoms and reduce the amount of tumor that needs to be treated by radiation or chemotherapy, so it is often the first step. Surgery is usually followed by radiation, which may be followed by or combined with chemotherapy. Radiation (with or without chemotherapy) is also used in cases where surgery is not possible.
Although glioblastoma remains difficult to treat, researchers are continually conducting clinical trials to better understand the formation of brain tumors and improve treatment. They are making hopeful new discoveries in such areas as delivering chemotherapy directly to the brain (to circumvent the blood/brain barrier which prevents drugs from traveling from the bloodstream to the brain), radiation sensitizers, immunotherapy, and gene therapy.