Less than a week after learning he has a rare form of brain cancer, U.S. Sen. John McCain had already hit the hiking trails in Arizona with his daughter Meghan. While his prognosis is uncertain, many may be wondering: What is glioblastoma? And what can people who have it expect?
To answer those questions and others, Health Matters spoke with Dr. Howard A. Fine, chief of the Division of Neuro-Oncology in the Department of Neurology at NewYork-Presbyterian/Weill Cornell Medical Center, and the founding director of the Brain Tumor Center and associate director for translational research at the Sandra and Edward Meyer Cancer Center at Weill Cornell Medicine.
What is glioblastoma?
Glioblastoma is the most common type of malignant brain tumor. Glioblastoma is what we call a primary brain tumor, meaning it starts out in the brain. The most common primary malignant brain tumors in adults are called gliomas, of which the very most common and malignant of those are glioblastoma. Glioblastoma can affect children or people in their 90s, but it’s most prevalent from ages 40 to 60. There are only 14,000 to 17,000 cases per year, but because it’s a disease that is very often fatal, glioblastomas exert a significant toll on a relatively young and productive population of patients and their families.
How is glioblastoma diagnosed?
Patients usually have some kind of neurological symptom like a headache, seizure, new weakness, confusion or vision problems. A doctor will order some type of scan, most commonly an MRI.
What causes glioblastoma?
We’ve looked for many associations, but the bottom line is, we don’t know what causes these tumors. There is no clear association. The only real risk factor we know of is, if you’ve had a history of cranial radiation, then you have a slightly increased risk. For the vast majority of patients who have glioblastoma, they don’t have that history of radiation. We don’t know what causes them, and they don’t run in families like prostate or breast cancer.
What is the typical prognosis for glioblastoma?
How you approach it with patients and what the real numbers are, are not exactly the same thing. That’s the art of medicine. The data are that the median survival for glioblastoma today is approximately 15 months. Median is a statistical number that means half of the patients do worse than that, and half do better. Do I have patients who are three years, five years, 10 years out from glioblastoma and are doing well? I do, but that’s not everyone. You have to have hope, but you also have to understand the realities for the majority of patients.
There are certain characteristics, which we call prognostic signs, that suggest who is more likely to do better than the median and who’s more likely to do worse. One of the strongest prognostic signs for this disease is age. The older you are, the much more aggressive the disease. What can be in a patient’s favor is being otherwise in good health. It’s also a positive sign, as in Sen. McCain’s case, when you can have a complete gross resection, meaning they took out all the tumor they could see. Those are positive prognostics.