How Does Bone Cancer Begin?

Genetic Mutations

Normal cells in the body have various mechanisms that control their growth, division and death. Consequently, typical cells in the bone grow or divide only when they are needed, or when they need to replace a dying cell. Cells become cancerous when they develop mutations in their genes that cause them to no longer be under the body's control. The cancerous cells continue to grow and divide and form a small mass called a tumor. Sometimes these cells even acquire mutations in their DNA that cause additional mutations to be more likely, which can give these cancerous cells the ability to make new blood vessels or to invade other tissues.

Bone Cancer Types

The most common form of bone cancer is called secondary bone cancer. This type of bone cancer results from cancer originating elsewhere in the body and spreading into the bone. On the other hand, it is possible for some types of cancer to begin in the bones themselves, known as primary bone cancer.

There are three main types of primary bone cancer: osteosarcoma, chondrosarcoma, and the Ewing sarcoma family. Osteosarcoma is cancer of the cells that make up the bone's hard matrix. Chondrosarcomas are cancers of the cartilage and connective tissue. Tumors in the Ewing sarcoma family are made up of soft tissue, such as fat, but can begin in the bone.

Risk Factors

The genetic mutations that cause bone cancer are sporadic, which means that they naturally occur as cells age and divide. There are, on the other hand, a number of factors that can predispose someone to develop bone cancer. These include certain inherited genetic disorders, such as hereditary retinoblastoma, Rothmund-Thomson syndrome, Li-Fraumeni syndrome and multiple exostoses. Another risk factor is Paget's disease of the bone. This is a condition that affects older adults and is a "precancerous" condition, which means that it forms abnormal cells that aren't cancerous but can easily become so. Finally, people who have had high doses of external radiation, such as people who have received radiation therapy, are more likely to develop bone cancer.