What Is Glioblastoma? 5 Facts About John McCain's Brain Cancer Diagnosis
Glioblastoma is considered by experts to be the most aggressive form of brain cancer among adults, meaning that it can rapidly grow within the brain.
"Glioblastoma tumors make their own blood supply, which helps them grow. It's easy for them to invade normal brain tissue," noted WebMD.
"Glioblastoma is a type of astrocytoma, a cancer that forms from star-shaped cells in the brain called astrocytes. In adults, this cancer usually starts in the cerebrum, the largest part of your brain."