Chicago high school security officer beats cancer, set to compete in marathon

CHICAGO - Tens of thousands of athletes will run in the Bank of America Chicago Marathon on Sunday, each one with a special reason for why they're pushing themselves to finish.

Miranda Davis is a security officer at Benito Juarez Community Academy in Chicago. She survived cancer and is motivated to run for herself and other cancer patients.

"When I was 16 months old I had a Stage 2 Wilms tumor that they were able to detect and remove. Went through chemo and then 30 years later, I decided a birthday gift to myself to run the marathon," Davis said.

Davis turned 30 last month and is ready to run her 26.2 miles. She's been training since April.

Eyes all over the world will be on the Chicago Marathon on Sunday. Athletes from all 50 states and more than 100 countries are in the Windy City for the event.

Between restaurants, hotels and shopping, this year's marathon is expected to bring in roughly $400 million for the city.