What is childhood bone cancer?

Cells in the bones sometimes change and no longer grow or behave normally. These changes may lead to non-cancerous tumours. But in some cases, changes to bone cells can cause bone cancer.

Bone cancer starts in or on the surface of a bone. A cancerous (malignant) tumour is a group of cancer cells that can grow into nearby tissue and destroy it. The tumour can also spread (metastasize) to other parts of the body.

When cancer starts in or on the surface of a bone, it is called primary bone cancer. Childhood bone cancer is rare. Non-cancerous (benign) bone tumours are more common. Find out more about non-cancerous tumours of the bone.

There are 2 main types of bone cancer that can happen in children.

Osteosarcoma is the most common type of childhood bone cancer. It can start in any bone in the body, but is most often found in areas where bone grows quickly, such as the long bones in the leg or the arm.

The most common sites for childhood osteosarcoma include these bones:

• the femur, located just above the knee

• the tibia, located just below the knee

• the humerus, located next to the shoulder

Ewing sarcoma is the second most common childhood bone cancer. It is often found in the axial skeleton, which includes the pelvis, ribs, spine and skull. It can also develop in the long bones of the legs and arms, usually in the bone shaft (also called the diaphysis). The most common sites for Ewing sarcoma in children are these bones:

• the pelvis (hip bone)
• the femur, located just above the knee
• the ribs
• the scapula (shoulder blade)
• the clavicle (collarbone)
• the sternum (breastbone)
• the tibia, located just below the knee
• the fibula, located just below the knee
• the skull

Sometimes, Ewing sarcoma can be found in the soft tissue outside of the bone. This is called extraosseous Ewing sarcoma.

Other types of cancer can spread to the bones, but this is not the same disease as primary bone cancer. Cancer that starts in another part of the body and spreads to the bone is called bone metastasis. It is not treated in the same way as primary bone cancer and needs treatment based on where the cancer originally started. Find out more about bone metastasis.