Pradeep,
I thought I would toss in my two cents on the situation. I was diagnosed with Stage IV RCC in June 11, also had my left kidney removed. I was put on 50mg sutent almost right away, the standard four weeks on, two weeks off. At first, it was borderline unbearable, I couldn't eat ANYthing, barely slept yet was so tired and constantly queezy with sporadic diarreha, thankfully never experienced the fevers...
The point is, that was almost a year ago and I'm still on sutent, in fact now on a more constant basis (37.5 for 6 weeks continuous) and I truly feel the only way I was able to do that was through the vaporization of marijuana, 3-4 times daily, with it I am able to eat, sleep and don't get nearly as sick as I used to, it completely changed everything..
Can't do anything about the mouth sores though :(