Glioblastoma is considered the most aggressive tumor that can form in the brain. Senator John McCain was diagnosed with one in July 2017.
Patients have a 10 per cent chance of surviving five years after their diagnosis, according to figures. The average lifespan is between 14 and 16 months.
Three adults per every 100,000 will be struck down with a glioblastoma, says The American Association of Neurological Surgeons (AANS).
It is most commonly found in men aged 50 to 60, and there is no link between developing glioblastoma and having a previous history with other cancers.
WHAT IS THE TUMOR MADE OF?
The tumor is made up of a mass of cells growing quickly in the brain, and in most cases patients have no family history of the disease.
It won’t spread to other organs, however, once it is diagnosed, it is nearly impossible to target, surgeons claim.
Unlike other types of brain cancer which are more specifically located, glioblastoma can occur in any part of the brain.
WHAT TREATMENT IS AVAILABLE?
Because the tumor likely already spread deep into the brain by the time it is diagnosed, the cancerous tissue is incredibly difficult to remove.
Surgeon will only ever remove the tumor, or part of the tumor, if it won’t do any damage to the surrounding brain tissue.
Dr Babcar Cisse, a neurosurgeon at the Weill Cornell Brain and Spine Center, told Daily Mail Online in July 2017: ‘By the time a glioblastoma is diagnosed, microfibers can spread to the rest of the brain which an MRI would not spot.
‘So even if the main tumor is removed and the patient receives radiation and chemotherapy, it will come back.’
GRADING A GLIOBLASTOMA
Brain tumors are graded from between one to four, depending on how fast they grow and how aggressive they are.
Malignant tumors are either given a high-grade three or four, while benign ones are given a lower grade one or two.
Glioblastoma is often referred to as a grade four astrocytoma – another form of brain tumor, says the AANS.
Patients typically complain of symptoms such as confused vision, trouble with memory, dizziness and headaches.
The symptoms are somewhat nonspecific, and vary from person to person, and may not persist.
Some patients suffer from blindness if the tumour compresses their optic nerve, which connects the retina to the brain, resulting in vision loss.
The disease is therefore impossible to diagnose based on symptoms alone.