Bone cancer is cancer that begins in the bone marrow. It\’s a very rare cancer. Cancer that extends from another part of the body into the surrounding bones is known as secondary bone cancer. 

The bones are made up of cells bound together by a material in which calcium is predominant. This makes them strong and rigid. The bones are hollow inside, where there is a spongy bone marrow that produces blood cells. The human body has more than 200 bones. Their functions are to support the body (long bones), to protect parts of the body (ribs and bones of the skull), and act as levers that allow us to move (tendons and cartilage of the bones).