I don't know Alexis but regardless I hope all outcomes are good ones. To help clarify the general specifics of brain tumors/cancer:

I would assume it's Glioblastoma multiforme because Oligodendrogliomas is typically not curable.

Using the term "stage" is an uneducated/layman's term for "RPA Class" also "grade" which is often times used by medical professionals. Some will say "stage" "class" and even so "level" and they all get used for the same general purpose.

Do your research if it means that much to you to know the specifics.