The Cancer That Felled John McCain: "... 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."(MEDICINE & HEALTH)

• Author: Engel, Mary
• Position: MEDICINE & HEALTH

JOHN McCAIN (R.-Ariz.) died of the same aggressive brain cancer that felled another Senate giant, Edward M. Kennedy (D.-Mass.), moving some to say that cancer really is bipartisan.

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 died at age 81 in August 2018, some 13 months after his diagnosis.

Here is the long view on glioblastoma diagnosis, treatment, and research from Fred Hutchinson Cancer Research Center:

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" --which is the supportive tissue of the brain. A glioblastoma is the most-malignant form of this tumor and is synonymous with a grade 4 glioma. Sometimes, glioblastoma also is 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% of all primary brain tumors. An estimated 12,390 cases are predicted for the coming year.

Sen. McCain previously had several early-stage melanomas removed and, while melanoma can metastasize to the brain, a primary brain tumor like McCain's forms because of abnormal cell growth in the brain tissue rather than spreading to the brain from elsewhere in the body. Melanoma, a deadly form of skin cancer, starts in melanocytes, the cells that give skin its color.

How was McCain's brain cancer different from former Pres. Jimmy Carter's cancer? Carter did have melanoma that had spread to his brain and liver, which he revealed in 2015. Until recently, someone whose melanoma had spread to the brain usually survived for only about four months. However, in 2011, melanoma became one of the first cancers to be treated with immunotherapy. After surgery to remove a small mass from his liver, Carter began receiving an immunotherapy drug called pembrolizumab (Keytruda), one of several "checkpoint inhibitors" that helps free the immune system to attack the cancer. Data from clinical trials shows that 50% of patients who received pembrolizumab for metastatic melanoma are alive three years later.

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 Eric...