Giving Compass' Take:

• Sen. John McCain has passed away after battling glioblastoma for over a year. The article below was originally published when McCain went public with his diagnosis.

• Philanthropic dollars can make a significant impact on research efforts in this space. The author explores four promising avenues.

• Read Giving Compass' comprehensive guide to cancer research and how donors can make an impact.

Glioblastoma is a particularly cruel enemy. Kennedy lived for 15 months after his diagnosis, which is about the median survival time for glioblastoma with treatment. He died in August 2009 at age 77.

McCain, who is now 80, spoke at the funeral. In words that could also describe himself, he praised Kennedy’s “bellowing laughter” and “uncanny sense for when differences could be bridged.” Noting his old friend’s passion for legislating — and life — McCain said, “He took the long view. He never gave up.”

What is glioblastoma?

The most common type of primary brain tumor is called a glioma, so named because it begins in the glial (the Greek word for “glue”), or supportive, tissue of the brain. A glioblastoma is the most malignant form of this tumor and is synonymous with a grade 4 glioma. Glioblastoma is also sometimes called a grade 4 astrocytoma because it arises from star-shaped cells called astrocytes, one of several types of glial cells. According to the American Brain Tumor Association, glioblastomas represent about 15 percent of all primary brain tumors. An estimated 12,390 cases are predicted for 2017.

What are the treatment options for glioblastoma?

Since 2005, a combination of surgery, chemotherapy and radiation has been the standard of care for glioblastoma, according to neurosurgeon Dr. Eric Holland, who is director of Seattle Translational Tumor Research and senior vice president and director of the Human Biology Division at Fred Hutch. McCain underwent a minimally invasive craniotomy with an eyebrow incision last week to remove what at first was described as a blood clot and later identified as glioblastoma. According to the statement from his office, further treatment options under discussion include chemotherapy and radiation.

Sadly, this aggressive cancer poses significant challenges to standard treatment, which is why median survival remains stuck at 15 months. (“Median survival” means the time, from diagnosis, at which half of patients are expected to still be alive.)

As Holland explains, glioblastoma is very difficult to completely remove surgically because it is so diffuse in the brain. The blood-brain barrier, which protects the brain and its associated fluid, limits the drugs that can reach tumors, and glioblastoma is resistant even to those drugs that can get in. Brain tissue, and especially brain cancer, is also resistant to radiation.

Read the full article about glioblastoma by Mary Engle at Fred Hutchinson Cancer Research Center.