The absence of healthy appetite. As some people already know, the healthy ration per day should be around 2000 calories for a grown-up adult. However, a grown person with a bone cancer does not want to eat at all. These patients start eating less without recognizing it. Sometimes, they don’t have an appetite during all day long. It means that the organism throws all energy to resist developing cancer. That’s why the body becomes quickly tired. Except for the decrease in appetite, the patients can notice the drop in overall activity.