Glioblastoma, an aggressive brain cancer that causes John McCain's death

Senior politician and US Senator John McCain died at the age of 81 on Sunday (8/26). He is known to have glioblastoma, an aggressive brain cancer.

Since the beginning of this year, McCain has never been seen in Washington. Later, he even stopped all forms of treatment for the disease.

Glioblastoma is a type of brain cancer. This is the most common type of malignant brain tumor among adults. And it's usually very aggressive, which means it can grow and spread quickly.

Glioblastoma is not like a brain tumor in general which starts from the body and then spreads to the brain, this disease is actually formed from star-shaped cells in the brain, called astrocytes.

Furthermore, this type of cancer tends to be risky in men than in women. And chances are, the risk is greater as you get older. In fact, from 2009 to 2013, doctors diagnosed nearly 11,000 cases of glioblastoma in the US each year.

Also read: John McCain, US senator and former presidential candidate, dies at 81 after battle with brain cancer

Because glioblastoma grows rapidly, pressure on the brain is usually the first symptom

Quoting CNN.com, the United States Brain Tumor Association said the disease included headaches, nausea, vomiting, and seizures.

In addition, this disease can cause a part of the body to be paralyzed, difficulty speaking, to disrupt a person's vision. All of these symptoms depend on the location of the tumor.

A doctor who was involved in dealing with John McCain, Dr. Sanjay Gupta said there was no specific treatment for this disease.

To diagnose, a neurologist (a doctor who specializes in diagnosing and treating brain disorders) will give a complete test. Patients may get an MRI or CT scan and other tests, depending on the symptoms experienced by the patient.

"Glioblastoma is cancer that is very evil, meaning that surgery must be done as soon as possible," he said as quoted from CNN on Sunday (8/26).

"This disease must be treated seriously with chemotherapy and radiation."

When cancer develops very quickly, Gupta adds, this means that the cell is spreading and starts attacking other parts through the bloodstream.

According to the United States brain tumor association there is no standard time related to glioblastoma treatment, but usually ranges from 14 months to three years.

Based on the results of a study of the United States brain tumor association in 2009, about 10 percent of Glioblastoma sufferers had the chance to live five years or longer if handled quickly and accurately.