What is Glioblastoma, the brain tumor Senator John McCain is diagnosed with?

Medical experts are talking about Glioblastoma, an aggressive brain tumor Arizona Senator John McCain was diagnosed with.

On Wednesday afternoon, a statement made by Sen. McCain's office revealed his diagnosis, and said the Senator and his family are reviewing further treatment options with a care team at Mayo Clinic, which may include a combination of chemotherapy and radiation.

While the diagnosis is scary, there is new research and treatment that has increased the survival rate for many people.

Dr. Peter Nakaji, a neurosurgeon with 14 years of experience, said a Glioblastoma tumor is among the most aggressive form of cancer, as it has the ability to invade the brain, and symptoms of Glioblastoma vary, depending on where the tumor is in the brain.

"If it's the part of the brain where vision is or speech is, those are all very different," said Dr. Nakaji. "Most people present with headache, vomiting, nausea, that kind of thing, from pressure in the head."

According to the American Brain Tumor Association, Glioblastomas are tumors that arise from star-shaped cells that make up the supportive tissue of the brain, and while generally found in the cerebral hemispheres of the brain, it can be found anywhere in the brain, or in the spinal cord.

According to the site, the exact cause of Glioblastoma is not known, and it may be difficult to treat because the tumors may contain many different types of cells.

Glioblastomas, according to the site, represents about 15.4% of all primary brain tumors. Incidence of the disease reportedly increases in frequency with age, and affect more men than women.

As with almost every Cancer diagnosis, the prognosis is among the biggest concern. Age can be a factor in battling Glioblastoma. Sen. McCain is 80.

"It always helps to be younger," said Dr. Nakaji. "In older people, it usually is more aggressive."