The exact cause of most bone cancers is not known. However, scientists have found that bone cancers are associated with a number of other conditions, which are described in the section on risk factors. Still, most people with bone cancers do not have any known risk factors. Research is underway to learn more about the causes of these cancers.

During the past few years, scientists have made great progress in understanding how certain changes in a person's DNA can cause normal cells to become cancerous. DNA carries the instructions for nearly everything our cells do. We usually look like our parents because they are the source of our DNA. However, DNA affects more than our outward appearance. It may influence our risks for developing certain diseases, including some kinds of cancer.

DNA is divided into units called genes. Genes carry the recipes for making proteins, the molecules that determine all cell functions. Some genes contain instructions to control when our cells grow and divide. Genes that promote cell division are called oncogenes. Others that slow down cell division or cause cells to die at the right time are called tumor suppressor genes. Cancers can be caused by DNA mutations (defects) that activate oncogenes or inactivate tumor suppressor genes. Some people with cancer have DNA mutations that they inherited from a parent. These mutations increase their risk for the disease.

The DNA mutations that cause some inherited forms of bone cancers are known (see the section, "What are the risk factors for bone cancer?"). In many cases, genetic testing can be used to see if someone has one of these mutations.

The majority of bone cancers are not caused by inherited DNA mutations. They are the result of mutations acquired during the person's lifetime. These mutations may result from exposure to radiation or cancer-causing chemicals, but most often they occur for no apparent reason. These mutations are present only in the cancer cells and so cannot be passed on to the patient's children.

Although scientists are making progress in understanding this process, there are still some points that are not completely understood. As their knowledge increases, they hope to develop ways to better prevent and treat bone cancers.

Last Medical Review: 07/14/2009
Last Revised: 07/14/2009