Non-invasive refers to the Stage. The Stage is how far has it progressed.
Aggressive means High Grade. Grade refers to how fast or slow it would tend to progress. If you click that link I posted above about stage and grade it will take you to a page that explains it all in detail.
So what your husband has is aggressive cancer, which is bad but it has not grown past the inner lining of the bladder (which is good). That means he had aggressive cancer but it was caught early and should therefor be more treatable than if it were not found until after it had gotten into the muscle.
Again, that link explains it better than I do.
Mike