Miller, who won a gold medal in 1996, told The Oklahoman she assumed she was still in good shape and nearly postponed the fateful appointment due to her busy schedule.
But she was glad she kept it because her doctor discovered a cyst the size of a baseball on her ovary. She underwent surgery and chemotherapy and was declared cancer-free last month.
The 34-year-old Oklahoma native said the hair loss and downtime were tough to take. "I'm typically a go-go-go girl and I had to take a step back on the days where I really couldn't work," she said.
She advised cancer patients to tackle their illnesses head on and not feel they are being selfish if they have to spend less time with family and others.
"You have to make health a priority because if you don't, you're not going to be there for everybody else," she said.