If you are talking about a class/course in HealthStream, it would depend on how the course was handled when it was cancelled.
At some organizations, when an event is cancelled, they just go in and delete it. In this case, you would have to create the class all over again. (or copy an existing event and modify it to reflect the canceled event information)
What I do when I cancel an event, is that I go in and write CANCELLED at the end of the name of the class and in the schedule access box select the "Do Not Show Class Schedule". That way, the class is still in HealthStream, but students can't see it or register for it. If I do this, and someone decides to go ahead with the event, it's a pretty simple process to remove the cancelled and change the display settings so that it shows again in the catalog. I also like that I can look back and see how many cancelled classes I have had (it's pretty rare), because someone will invariably ask me "didn't we offer 'suchandsuch' class this year?" and I can look back and say, "yes, we offered it 5 times and cancelled 3 of those".
I hope this is what you were looking for..