Bone Cancer

Bone cancer is a sarcoma (type of cancerous tumor) that starts in the bone. Other cancers may affect the bones, including cancers that metastasize, or spread, from other parts of the body, as well as non-Hodgkin's lymphoma and multiple myeloma. The information on this page focuses on cancers that start in the bones (primary bone cancer).

Bone structure

Bones support and give structure to the body. They usually are hollow. The main parts of the bones are:

Matrix is the outer part of bones. It is made of fiber-like tissue and is covered with a layer of tissue called the periosteaum.

Bone marrow is the soft tissue in the space in hollow bones called the medullary cavity. Cells inside bone marrow include:

• Fat cells
• Red blood cells, white blood cells and platelets
• Fibroblasts, a type of cell that helps build connective tissue
• Plasma, in which blood cells are suspended

Cartilage is at the end of most bones. It is softer than bone, but it is firmer than soft tissue. Cartilage and other tissues, including ligaments, make up joints, which connect some bones.

Bone constantly changes as new bone forms and old bone dissolves. To make new bone, the body deposits calcium into the cartilage. Some of the cartilage stays at the ends of bones to make joints.

Bone cancer types

There are several types of bone tumors. They are named according to the area of bone or tissue where they start and the type of cells they contain. Some bone tumors are benign (not cancer), and some are malignant (cancer). Bone cancer also is called sarcoma.

The most commonly found types of primary bone cancer are:

• Osteosarcoma or osteogenic sarcoma is the main type of bone cancer. It occurs most often in children and adolescents, and it accounts for about one-fourth of bone cancer in adults. More males than females get this cancer. About 1,000 people in the United States are diagnosed with osteosarcoma each year. It begins in bone cells, usually in the pelvis, arms or legs, especially the area around the knee.
• Chondrosarcoma is cancer of cartilage cells. More than 40% of adult bone cancer is chondrosarcoma, making it the most prevalent bone cancer in adults. The average age of diagnosis is 51, and 70% of cases are in patients over 40. Chondrosarcoma tends to be diagnosed at an early stage and often is low grade. Many chondrosarcoma tumors are benign (not cancer). Tumors can develop anywhere in the body where there is cartilage, especially the pelvis, leg or arm.
• Ewing's sarcoma is the second most prevalent type of bone cancer in children and adolescents, and the third most often found in adults. It accounts for about 8% of bone cancers in adults. Ewing's sarcoma can start in bones, tissues or organs, especially the pelvis, chest wall, legs or arms.

Less-commonly found types of bone cancer include:

• Chordoma, which is found in 10% of adult bone cancer cases, usually in the spine and base of the skull
• Malignant fibrous histiocytoma/fibrosarcoma, which usually starts in connective tissue
• Fibrosarcoma, which often is benign and found in soft tissue in the leg, arm or jaw
• Secondary (or metastatic) bone cancer is cancer that spreads to the bone from another part of the body. This type of bone cancer is more prevalent than primary bone cancer. For more information about this type of cancer, see the type of primary cancer (where the cancer started).

Bone cancer risk factors

Anything that increases your chance of getting bone cancer is a risk factor. However, having risk factors does not mean you will get bone cancer. In fact, most people who develop bone cancer do not have any risk factors. If you have risk factors, it’s a good idea to discuss them with your health care provider.

Teenagers and young adults are at greatest risk of developing osteosarcoma, a type of bone cancer, because it often is associated with growth spurts.

Some diseases that run in families can slightly increase the risk of bone cancer. These include:

• Li-Fraumeni syndrome
• Rothmund-Thompson syndrome
• Retinoblastoma (an eye cancer of children)
• Multiple osteochondromas
• Genetic counseling may be right for you. Learn more about the risk to you and your family on our genetic
  testing page.

Other risk factors for bone cancer include:

• Paget’s disease
• Prior radiation therapy for cancer, especially treatment at a young age or with high doses of radiation
• Bone marrow transplant