Ewing's sarcoma is a very rare cancer that appears as a solid tumor, most often in children and teens. Most cases occur between ages 10 and 20, and about one quarter occur before age 10. Only a small percentage of people with Ewing's sarcoma are older than 20. Nearly everyone with this cancer is white.
Because Ewing's sarcoma typically develops in bones, it used to be considered a bone cancer. But it actually arises from a type of primitive nerve cell. That's why Ewing's sarcoma can occur outside bones, in the body's soft tissues. When it does, it is called non-osseous Ewing's sarcoma.
Ewing's sarcoma usually develops in the arms or legs. However, it can occur in the pelvis, ribs, spine, and, in rare cases, other bones or soft tissues. When diagnosed, about a quarter of Ewing's sarcomas have spread (metastasized) to another part of the body. The most common sites for a metastasis are
the bone marrow.
Like other cancers, Ewing's sarcoma is caused by abnormal cells that multiply out of control. The cells of Ewing's sarcoma have a change in the chemical material (DNA) that the person inherited from his or her parents. This change, called a translocation, usually involves a rearrangement of DNA between two chromosomes. The problem, however, is not inherited. It develops after birth.
Ewing's sarcoma does not seem to be related to
exposure to radiation
exposure to chemicals
other environmental factors.
No one knows what causes the genetic change that leads to Ewing's sarcoma.