How likely is ewings sarcoma coming back after five years?

It depends: Overall rate of event free survival, meaning the tumor doesn't return in the same spot or spreads somewhere, is about 70% at 5 years. If the tumor hasn't returned at 5 years, it's unlikely to pop up later in life, though it is possible. Every case is different, though. Just do what you can to maximize your chances of beating the cancer and pray for the best. Good luck.

Unlikely: Ewing sarcoma recurrence is most common within the first two years of diagnosis 90% of the time. After 5 years it is highly unlikely, but there are still reports of late recurrences in ewing sarcoma.