Just wondering if there is a way to eliminate or control the room tone.
yeah, it's all about room treatment and mic placement. if it's something like a radio VO, then you have more freedom to dampen high end. that's pretty easy, you just use blankets and stuff. and then close-mic for proximity effect.
but if it's going to be used for something else, like go with picture or with a song, then you have to treat all frequencies more evenly. that's a lot harder -- you need broadband absorption and have to watch out for reflections. if you can suspend a blanket, say, 5 feet above the subject's head, but allow for some reflection to get a sense of space (but not sound like he's in a tank or a bathtub or a bathroom, etc), then you can get good results.
but that's all quality of recording. your original question had to do with noise cancellation, and i don't know if it still does. what kind of noise are you looking to get rid of? self-noise? traffic noise? lip smacks and p's popping? regardless, it's always best solved at record-time.