He never smoked, never drank, worked out almost every day and passed his annual physical with flying colors. So no one was more surprised than Alan Fenton when, in June 2005, doctors discovered a 10-pound tumor growing in his chest. It was not the birthday present the 65-year-old was expecting.

His doctor "came into the room with my test results and said, 'I'm so sorry,' " he recalled. "She told me I had lung cancer but I said, 'No, I never smoked. I don't have lung cancer.' "