Can I ask how can I know whether a person is having a bone cancer? As my friend back ache will attack once a month and sometimes twice. But we can't differentiate out whether it is a back ache or bone ache. And she never wanted to consult a doctor. Some more there is one time, when we went to seek for a doctor advice, the doctor said that it is the standing posture problem, that's why will make the back ache. The doctor never undergo any x-ray for her anyway.