BONE CANCER

BONE CANCER is an uncontrolled growth of abnormal cells within the bone. Bone provides structure to the body, protects internal organs, and produces and stores blood cells. Bone also acts as levers and braces for muscles to produce movement.
Bone tumors can be either benign (noncancerous) or malignant (cancerous). Both types can grow and compress normal bone tissue and absorb or replace it with abnormal tissue. Benign bone tumors, which are more common, do not spread and are rarely life-threatening.
The two main forms of cancer found in bone are primary bone cancer and secondary bone cancer. Primary bone cancer begins in the bone. Secondary bone cancer, or metastatic bone cancer, does not begin in the bone but has spread there from another area of the body. Secondary bone cancer often results from the spread of cancer from the lung, breast or prostate
Primary bone cancer is rare and accounts for less than 0.2 percent of all cancers. It is much more common for cancer to spread to a bone from another site of origination. Types of primary bone cancers include:
* Osteosarcoma
** Chondrosarcoma
*** Chordoma
**** Fibrosarcoma and malignant fibrous histiocytoma
***** Giant cell tumor of the bone
The exact cause of bone cancer has not been identified. Recently researchers have gained a greater understanding of how specific changes in DNA may cause bone cells to become cancerous. In addition, researchers have identified a number of factors that may make a person more likely to develop bone cancer, including retinoblastoma (a rare eye cancer of children), Paget's disease and exposure to large doses of radiation.