Montefiore doctors are offering their insights following Sen. John McCain's diagnosis of glioblastoma – an aggressive form of brain cancer. 

Dr. Nrupen Baxi, a neurosurgeon at Montefiore Medical Center, says the cancerous growth is one of the more common forms of brain cancer.

It affects mostly older people, but can affect people of all ages and races, according to Dr. Baxi.

"It's a very serious condition," Dr. Baxi says.

The most common warning signs of glioblastoma include headaches, seizures and difficulty speaking.

Dr. Baxi says the treatment often involves a combination of chemotherapy, which is administered by pill and radiation. 

"The radiation lasts for a few weeks and usually involves going every day for treatments," he says. 

Although common, the doctors says this type of brain cancer is the hardest to treat. On average, doctors say the survival rate of the disease ranges from 14 to 18 months.

Sen. McCain took to Twitter, saying: I greatly appreciate the outpouring of support - unfortunately for my sparring partners in Congress, I'll be back soon, so stand-by!