I have a stage 4 tumor the size of a softball in my pelvis, and it is EXREMELY painful. I'm not sure if I've ever been told that the meds we take can cause pain at the tumor site. When I began exemestane, it didn't seem to cause any extra pain, but I did have the other side effects, such as overall joint pain. I will begin Ibrance soon and hope the side effects are minimal (fingers crossed!)