Charles, a longtime CNN sportscaster, has been part of Showtime's ShoBox series since it began in 2001. The 63-year-old journalist began treatment last week at the University of Houston.

Charles was among the first reporters hired by CNN, hosting programs for the cable news network for 21 years. He also hosted several Goodwill Games broadcasts for Turner Sports.

"Having bladder cancer is clearly the greatest challenge of my life," Charles said. "Now it's time for a face-first assault. Like a fighter, just give me one round at a time and I'll eventually win."