I labeled the daily emails from our March trip to MD Anderson for my brother’s stem cell transplant “our adventure,” and that’s exactly what it turned out to be.

I was excited to be a stem cell donor for my brother, Dan, who has leukemia. But when the doctors performed a chest x-ray, they discovered a questionable spot on my lung. We hoped it was nothing, but scheduled a CT scan to make sure.  

The scan revealed...