Bone cancer

Malignant growth in bone, which may originate in the bone itself (primary bone cancer) or, more commonly, occur as a result of cancer spreading from elsewhere in the body (secondary, or metatastic, bone cancer). Primary bone cancers are rare. The type that occurs most often is osteosarcoma. Other types include chondrosarcoma and fibrosarcoma. Bone cancer can also start in the bone marrow (see multiple myeloma and leukaemia). The treatment of primary bone cancer depends on the extent to which the disease has spread. If it remains confined to bone, amputation may be recommended; but it may be possible to remove the cancer and fill the defect with a bone graft. Radiotherapy or chemotherapy, or both, may also be needed The cancers that spread readily to form secondary bone cancer are those of the breast, lung, prostate, thyroid, and kidney. These bone metastases occur commonly in the spine, pelvis, ribs, and skull. Pain is usually the main symptom. Affected bones are abnormally fragile and may easily fracture. Bone cancer that affects the spine may cause collapse or crushing of vertebrae, damaging the spinal cord and causing weakness or paralysis of one or more limbs. Secondary bone cancers from the breast and prostate often respond to treatment with hormone antagonists.