By the time I got to MD Anderson in early 2011, I was very, very sick. I’d been diagnosed with a type of non-Hodgkin lymphoma called B cell lymphoma several months earlier. It was stage III. But the treatment I’d been receiving at a local hospital system wasn’t working. I needed to try something different.

A large tumor in my abdomen was about the size of a small grapefruit. It was pressing against my rib cage and squashing my...