I can’t quite explain what it feels like to get the cancer call. You can’t describe it unless you’ve heard those words.

I don’t think that changes whether it’s your first or, in my case, third diagnosis. When I learned that I had stage III melanoma last January, my first thoughts were: how do I have stage III cancer? I eat more veggies before 10 a.m. than most eat all day. I teach cycling classes and exercise six days a week. I...