After undergoing a surgery to remove a blood clot from above his left eye, a tissue pathology found a certain kind of tumor in John McCain's brain that might prove hard to treat.
The kind of tumor McCain has is called a "glioblastoma." According to the American Brain Tumor Association (ABTA), a glioblastoma is a highly cancerous tumor involving the supportive tissue of the brain. While the cause of the tumor is unknown, glioblastomas are known to grow rapidly as the cancerous cells quickly reproduce.
According to the ABTA, glioblastomas can be hard to treat because they are composed of more than one kind of cell. "Some cells may respond well to certain therapies, while others may not be affected at all," the website reads. "This is why the treatment plan for glioblastoma may combine several approaches."
The first step, of course, is removing the tumor as much as possible, but can be followed up with treatments to slow the growth of the cancer. The statement released by McCain's office seems to acknowledge this fact, as it states he is looking at treatment options and that "may include a combination of chemotherapy and radiation." The ABTA reports that the prognosis for an adult with a glioblastoma depends on how aggressive the tumor is and ranges from a little over a year to possibly five years.
The glioblastoma and the blood clot were found near McCain's left eye, not far from where he had a cancerous melanoma lesion removed in 2000. According to a doctor who spoke to The New York Times, melanoma is known to make its way toward the brain.
A statement from the senator's office read:
Senator McCain appreciates the outpouring of support he has received over the last few days. He is in good spirits as he continues to recover at home with his family in Arizona. He is grateful to the doctors and staff at Mayo Clinic for their outstanding care, and is confident that any future treatment will be effective.
His daughter Meghan McCain released a strong statement of her own, writing that her father was the toughest person she knows. "Cancer may afflict him in many ways: but it will not make him surrender," she wrote. "Nothing ever has."