Bone Cancer

The two types of bone cancer are primary and secondary. Primary bone cancer originates in the bone or tissues adjoined to the bone such as connective tissue. Secondary bone cancers, also known as bone metastases, are cancers that originated in another place in the body and then spread to the bone. The cells in bone metastases resemble the cells from the cancer's origin. They are not bone cells that have become cancerous, as in the case of primary bone cancers.
Primary bone cancers: The most common types of primary bone cancers include Osteosarcoma, Chondrosarcoma, and Ewing's sarcoma. Osteosarcoma develops in new tissue of growing bones and occurs most commonly in children or adolescents. Chondrosarcoma originates in cartilage, which is a type of connective tissue that serves as a protective layer between bones ends. Ewing 's sarcoma originates in immature nerve tissue within bone marrow. This type of bone cancer also occurs more frequently in children and adolescents. Less common bone cancers include malignant fibrous histocytoma and fibrosarcoma. These cancers are similar to Osteosarcoma in that they occur mainly in the extremities, except they occur in adults.

Cancers Metastatic to Bone or (Secondary bone cancers): Although most cancers can spread to or invade bone, the most common cancers that spread to bone are multiple myeloma, breast, prostate, lung, kidney, and thyroid cancer. The ribs, pelvis and spine are normally the first bones impacted by bone metastases, while bones more distant from the central skeleton are less frequently affected. It is not well understood why certain cancers metastasize to bone more than others. However, some general observations about bone metastases are as follows:

Breast cancer is the most common type of cancer to spread to bone, followed by prostate, then lung.Carcinomas, or cancers that arise from tissues that line or cover organs, are much more likely to metastasize to bone than sarcomas, cancers that originate in connective tissue (cartilage, fat, or muscle).Bone metastases from kidney cancer may occur many years after the primary cancer has been treated.The first symptom of bone cancer is usually pain or tenderness near the cancer. Bone pain is caused by stretching of the periosteum (thick membrane that covers bone) by the cancer, or by stimulation of nerves within the bone. Bone pain may be hard to differentiate from ordinary low back pain or arthritis. Usually the pain due to bone metastasis is fairly constant, even at night. It can be worse in different positions, such as standing up, which may compress the cancer in a weight bearing bone. If pain lasts for more than a week or two, doesn't seem to be going away, and is unlike other pain that may have been experienced, it should be evaluated by a physician.