who is at risk for osteosarcoma?
<answer> Children and teens are at risk for osteosarcoma. <context> Osteosarcoma is cancer of the bone. The cancer (malignant) cells make immature bone cells (osteoid). Osteosarcoma is rare, but it is the most common type of bone cancer in children and teens. It is most common when teens have growth spurts. That is between the ages of 13 and 16.