WHAT IS BONE CANCER?
Primary bone cancer refers to cancers which start in the bone. These are different to secondary bone cancers which started in other parts of the body and later spread to the bones.
Bone cancers are tumors which have the potential to spread to other parts of the body. These are different to benign (non-cancerous) bone tumors which do not spread. Benign bone tumors are more common than malignant (cancerous) bone tumors.
Secondary bone cancer is where malignant cells have spread to the bones from other parts of the body. This is different to cancer that actually started in the bones (primary bone cancer). Virtually all types of cancer can spread to bone. Bone metastases are particularly common in people with breast, lung or prostate cancer. Bone metastases are usually multiple, they cause pain and can can lead to other symptoms such as hypercalcemia (abnormally high levels of calcium in the blood),
There are over 200 bones in the human body, any of these can be affected by cancer. However, certain types of bone cancer are more common in specific bones.
Osteosarcoma is most commonly found in the bones around the knee. Ewing's sarcoma is more common in the upper leg, pelvis and other bones of the trunk. The pelvis is the most frequent location for chondrosarcoma. Nevertheless, it is possible for these cancers to affect any bone in the body.
There are several kinds of cancer that start in the bones. In children and young adults under 30 the most common types are Osteosarcoma and Ewing's sarcoma. Osteosarcoma develops in new tissue (osteoid) in growing bones, and is most often found in the bones around the knees. Ewing's sarcoma is is thought to arise from immature nerve tissue in the bones and is seen in many bones, particularly the pelvis and upper leg. In adults other common cancers include chondrosarcoma which starts in cartilage, chordoma, malignant fibrous histiocytoma of bone and fibrosarcoma of bone; these are all rare in children. There are a number of other rare types of bone cancer.
Bone cancer is most common in the young. Osteosarcomas and Ewing's sarcomas are generally diagnosed in children in their teens or in young adults in their 20's. More boys are diagnosed with primary bone cancer than girls. Other rarer types of primary bone cancer are most often diagnosed in middle-aged adults.
There are a number of different types of primary bone cancer. The most common is osteosarcoma. It is most often diagnosed in teenagers or young adults. Osteosarcomas can grow anywhere in the skeleton. They typically develop in the thigh bone (the femur) and shin bone (the tibia). The most common sites are the: lower thigh (femur); upper shin bone (tibia); upper arm (humerus) and lower shin bone (fibula).
Sarcoma tumors of the bone by name:
Askin's tumor (PNET of the chest wall) aka peripheral neuroepithelioma
primitive neuroectodermal tumor (PNET)
conventional intramedullary osteosarcoma
small cell osteosarcoma
intraosseous well-differentiated osteosarcoma
high-grade surface osteosarcoma
Another type of bone cancer is Ewing's sarcoma. This is named after Dr. James Ewing who described the tumour in the 1920s. This bone cancer is also most often diagnosed in teenagers and young adults. Ewing's sarcomas most often start in the pelvis, thigh (femur) or shin (tibia) bones.
The Ewing's family of tumors are rare diseases in which cancer (malignant) cells are found in the bone and soft tissues. Ewing's family of tumors most frequently occurs in teenagers. Once one of the Ewing's family of tumors has been found, more tests will be done to find out if cancer cells have spread to other parts of the body. This is called staging. At present, there is no formal staging system for the Ewing's family of tumors. Instead, most patients are grouped depending on whether cancer is found in only one part of the body (localized disease) or whether cancer has spread from one part of the body to another (metastatic disease). Extraosseous Ewing's has been grouped using the rhabdomyosarcoma staging system because they are both soft tissue tumors.
Chondrosarcoma is a type of primary bone cancer most often diagnosed in middle aged adults. It is very rare. The cancer produces cartilage (chondroid). This is the shiny, smooth substance that normally covers the ends of bones in the joints. Chondrosarcoma can grow inside a bone or on the bone surface. So islands of cartilage can be found inside the bone or on the surface in an area where it wouldn't normally grow. This bone tumor is usually slow growing. The most common sites for chondrosarcoma are the: pelvis; thigh bone (femur); upper arm (humerus); shoulder blade (scapula) and ribs.
Cartilage tumors by name:
clear cell chondrosarcoma
extraosseous myxoid chondrosarcoma
extraosseous mesenchymal chondrosarcoma