Are there any runners out there that have suffered from a long term illness that prevented them from running?

I’m being hopeful, today – trying to think ahead. I am still being treated for cancer and I was told to stop running when I started having major complications. After talking to a doctor today, he’s not ruling out my return to running; however, warned that it takes a while to work back into running. Has anyone else had to work their way back into running? Any good tips or things (really restricted on activities, right now) I should be doing to prepare?

I don’t have the green light, yet; however, I’m holding out hope for the yes, before January!