Ewing's sarcoma is a primary bone cancer that affects mainly children and adolescents. It's one of a group of cancers known collectively as the Ewing sarcoma family of tumors -- ESFT or sometimes just EFT. It's the second most common bone cancer in children, but it's also relatively uncommon. It accounts for only 1% of all childhood cancers. Although it can occur at any age, it very rarely occurs in adults over the age of 30.
Because many illnesses can cause the same symptoms as Ewing's sarcoma, it's sometimes missed in its early stages. But early diagnosis and treatment is important. If found early enough, before it spreads to multiple organs, Ewing's sarcoma can be treated successfully in 50% to 75% of cases.
Many of the medical and scientific terms used in this summary are found in the NCI Dictionary of Genetics Terms. When a linked term is clicked, the definition will appear in a separate window.
Creating evidence-based summaries on cancer genetics is challenging because the rapid evolution of new information often results in evidence that is incomplete or of limited quality. In addition, established methods for evaluating the quality of the evidence are available for some, but not all, aspects of...
Primary bone cancer is cancer that originates in bone cells. The other way cancer can occur in bones is after spreading there from another part of the body through a process called metastasis. When it does, it's called secondary bone cancer. Secondary bone cancer is the same type of cancer that exists in the tissue or organ where it first occurred. For instance, breast cancer that spreads to the bones is still made up of breast cancer cells.
Researchers think that Ewing's sarcoma begins in a certain kind of primitive cell. And although the tumors typically start forming in bone, they can also start in the same kind of cells outside of bone. When this occurs, it's called an extraosseous Ewing's sarcoma.
Ewing tumors that grow in bone are typically found in the long bones of the legs and arms, or bones in the chest, trunk, pelvis, back, or head. In addition to the classic Ewing tumor, which is named for the doctor who first described it, James Ewing, there are two other types of bone tumor that belong to the Ewing family of tumors. One is called primitive neuroectodermal tumor or PNET. This tumor often times arises in the brain. The other is known as an Askin tumor, which usually arises in the chest wall.
There are differences in these types of tumors. But the cells that make them up are similar, they have the same DNA abnormalities, and they share proteins that aren't found in cells of other cancers. All of the cancers progress in the same way, and all are treated the same way.
What Causes Ewing's Sarcoma?
In all Ewing Family Tumors, a change occurs in a cell to move a gene called EWS on chromosome No. 22 next to a section of DNA on one of several other chromosomes that causes the EWS gene to turn on. No one knows why this happens. It is not inherited; rather it occurs after the child is born. This change can be tested for in the biopsy specimen used to confirm the diagnosis.