What is childhood bone cancer?

Primary childhood bone cancer starts in bone cells. Primary bone cancer is rare. It is not the same disease as cancer that starts in another part of the body and spreads to the bones (called secondary bone cancer or bone metastases).


Structure of a Long Bone_Overview


When we are born, we have about 270 bones. Some of these bones eventually join together to form the 206 bones in an adult skeleton. The skeleton is the inner framework that supports your body. Bones also protect the organs inside the body. The ends of bones are covered by cartilage. Cartilage is a tough, flexible material that is more elastic than bone. It stops the bones from rubbing against each other and lets them move freely at the joints.


Bones are made up of bone cells (osteocytes, osteoclasts and osteoblasts), nerves, blood vessels and minerals. They store and release minerals (such as calcium and magnesium) that your body needs. Most bones are filled with a soft, spongy material called bone marrow. There are 2 types of bone marrow. Red bone marrow makes and stores blood cells. Yellow bone marrow stores fatty tissue.


If an abnormal bone cell develops, a tumour may start to grow in a bone. These tumours could be benign (non-cancerous) or malignant (cancerous). There are several types of bone cancer. Each type of bone cancer behaves differently and is treated differently.

  • Osteosarcoma is the most common type of bone cancer. It starts most often in the end of a long bone, especially around the knee. Osteosarcomas tend to spread to other parts of the body, especially the lungs.
  • Ewing sarcoma is the second most common bone tumour in children. It usually begins in the pelvis, breastbone (sternum), ribs, spine or skull. These tumours can also develop in the middle part of long bones in the arms or legs, or in the soft tissues of the body rather than the bone

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We can give information about cancer care and support services in Canada only. To find a cancer organization in your country, visit Union for International Cancer Control or International Cancer Information Service Group.