Genres ... oh the misery

Ok, maybe someone here can help me.

I am almost done with my WIP, which is a thriller novel. I consider it mainstream fiction, and it has the literary form of a thriller, one set in the near future (next 50 years).
So my question is this: Is "thriller" its own genre in the genre fiction range, or is it a flavor of mainstream commercial fiction? Also, do you think that its setting being in the future means that it by definition needs to be classified as science fiction?