5 questions about the brain cancer diagnosed in Sen. John McCain

Glioblastoma, the cancer with which Sen. John McCain, R-Ariz., has been diagnosed, is a highly lethal malignancy that killed Sen. Edward Kennedy, D-Mass., and Beau Biden, the son of former Vice President Joseph Biden. Here is what you need to know: What is glioblastoma? Glioblastoma is an aggressive...