And how bad is loss of appetite? Does it just change or is it totally gone? Is it the appetite that effects weight or is it an increased metabolism, or both? Also, how prevalent is weight loss, loss of appetite, and fever with advanced cancers?

Neither generally comes first. Where did you even get that idea?Cancer doesn’t cause a fever and unless you have a later stage cancer involving the digestive system, you probably won’t have any weight loss. I’ve met many people this past year with cancer and the only one with any weight loss was an old man with stomach cancer that had metastasized to ther organs. He was in a very advanced stage and didn’t live much longer.