UAB Medicine News


Glioblastomas: Facts About Sen. John McCain’s Type of Brain Cancer

U.S. Sen. John McCain (R-AZ) had a malignant (cancerous) brain tumor removed last week, a type of cancer called glioblastoma. Glioblastomas account for 15% of brain tumors, and some 24,000 cases are diagnosed each year. Here are 5 things you need to know about this form of cancer:

1.  Glioblastomas arise from astrocytes, the star-shaped cells that make up the “glue-like” supportive tissue in the brain. Normally these tumors are highly malignant (cancerous) because the cells reproduce quickly and they are supported by a large network of blood vessels.

2.  Like most kinds of cancerous tumors, the cause of glioblastomas is not known. Sen. McCain underwent treatment for melanoma (skin cancer) in 2000, but doctors say there is no clear connection between the two forms of cancer.

3.  Because glioblastomas tend to grow rapidly, the most common symptoms are usually caused by increased pressure in the brain. These symptoms can include headache, nausea, vomiting, and drowsiness, as well as weakness on one side of the body, memory and speech difficulties, and vision changes. Sen. McCain had recently experienced fatigue and double vision.

4.  The median survival time for adults with aggressive glioblastomas, if treated, is about 14.6 months, and the two-year survival rate is 30%. However, a 2009 study reported that almost 10% of patients with glioblastoma may live five years or longer. Sen. McCain’s doctors say they believe they successfully removed all of the tumor tissue, but microscopic pieces can remain. “There will always be cells that move beyond the borders of what you can see on an MRI,” said one of McCain’s doctors, who was quoted in a press statement. “That’s one reason why it’s so deadly.”

5.  The UAB Comprehensive Cancer Center has partnered with Michigan-based Strata Oncology on a research trial to provide no-cost tumor sequencing to UAB cancer patients who have tumors that can’t be removed surgically or have spread to another part of the body. Since tumors often respond differently to treatment depending on genetic factors that vary from person to person, analyzing a tumor with genetic sequencing can provide valuable insight into how to treat it. Such tests normally cost $3,000 to $4,000 each and aren’t typically covered by insurance.