After more than a year of using a wheelchair, Abby Lee Miller took her very first steps in public on "The Doctors." Through tears, Miller pulled herself up and used a walker to take a few steps, as the audience cheered her on. "This is scary, you have no idea," she said. She shared a clip of the moment on Instagram, writing in part, "Watching this made me cry!" Miller was diagnosed with cancer last year and had to undergo emergency spine surgery to remove a tumor wrapped around it.