Everything you need to know about Sen. John McCain’s brain tumor

U.S. Sen. John McCain’s brain tumor is a type known as glioblastoma.

So what is a glioblastoma?

It is a highly malignant form of cancer that spreads quickly and is known to be fed by a large network of blood vessels in the brain, according to this NBC News report.

The sad news for the former Republican presidential nominee came out Wednesday after doctors operated on a small clot about McCain’s left eye.

Glioblastoma is a mass of abnormal cells growing in the brain. The tumor grows from star-shaped cells known as astrocytes that make the supportive tissue of the brain. Brain tumors, unlike other cancers, do are not hereditary except in rare cases.

The American Cancer Society estimates that about 24,000 malignant tumors are diagnosed each year — about three in 10 of them are glioblastomas.

Also unlike other cancers, glioblastomas don’t spread to other organs.

McCain’s doctors believe they removed all of the tumor tissue, but cancerous cells could remain and spread to other parts of the brain. It is often difficult to remove glioblastomas because they often spread deep into the brain by the time of diagnosis.

The diagnosis often occurs after a patient suffers a seizure.

McCain also has a history deadly skin cancer known as melanoma. A 2014 study published in the Annals of Epidemiology found glioblastoma was associated with melanoma.were greater among melanoma cases than in people who had never been diagnosed with skin cancer.

The senator’s symptoms may include double vision, forgetfulness or headaches.

Treatment usually is a combination of chemotherapy drugs and radiation on a daily basis. Gene therapy has shown some promise in fighting the tumor.

The prognosis for recovery from glioblastoma is not good.  The median survival rates range from 14 months to three years.

The veteran lawmaker from Arizona fought in Vietnam and was a prisoner of war for more than five years. He is currently recovering at his home.

To read the whole NBC News report click here.

(Featured photo courtesy of Medill DC/Creative Commons)