Depending on your circumstances, would you consider trying homoeopathy so that you do not need to have the kidney removed?
It is not guaranteed, but homoeopathy can act in a way that conventional medicine cannot touch. I know that non-functioning kidneys have been made to work again by means of well prescribed homoeopathic remedies.
If you want to try it, you don't need to cancel the op, just defer it while you see if homoeopathy can help. And find an excellent and experienced homoeopath to treat you.