McCain’s cancer, glioblastoma, described as ‘very aggressive tumor’

Republic reporters explain what glioblastoma is and what it means for Sen. John McCain.

Glioblastoma, the type of brain tumor diagnosed in Sen. John McCain, is an aggressive type that is difficult to treat, experts say.

“It’s a very aggressive tumor,” said Dr. Joseph Zabramski, a neurosurgeon at Barrow Neurological Institute in Phoenix. “In general, it is a tumor that has relentless force. You can slow it down but not stop it.”

Michael Berens, deputy director of the Translational Genomics Research Institute in downtown Phoenix, said unlike other cancers, glioblastoma “begins and then spreads within the brain with finger-like projections.”

“The tumor cells wander around and create guerilla warfare in the brain,” Berens said.

McCain’s office said Wednesday the tissue of concern was removed during a craniotomy. The senator and his family are reviewing further treatment options with his team at Mayo Clinic.

Berens, who has studied glioblastoma for 30 years, said patients who contract the cancer and undergo surgery, radiation and chemotherapy live on average 16 to 18 months.

U.S. Sen. John McCain at his office in Phoenix on Monday,

Berens added that only about 18,000 Americans are afflicted with glioblastoma.

Zabramski said patients generally take at least a few weeks after a tumor is surgically removed to assess other treatment options. That may include genetic testing of the tumor that can inform doctors which type of treatment may be most…