When Robert Alvarez was diagnosed with a low-grade insular brain tumor in 2013, he decided to hope for the best and postpone treatment.

“The doctors told me surgery could leave me paralyzed,” Robert recalls. He noticed increasing headaches and clumsiness, but the symptoms were still manageable. As an active 19-year-old athlete and musician, Robert felt the risks of surgery were worse than living with the brain tumor.  ...