Another childhood cancer, primitive neuroectodermal tumor (PNET), shares many features with Ewing’s tumor. PNETs are rare cancers found in soft tissue and bone. It was questioned if Ewing’s, EOE, and PNET were in the same family, and now it’s been shown that PNET and Ewing’s both arise from the same primitive cell. The tumors are now called the Ewing’s family of tumors (EFT) or a tumor of the Ewing’s family (TEF). Of the tumors in this family, Ewing’s tumor of bone represent 87 percent, while EOE (at eight percent) and PNET (at five percent) are much rarer.

TEF can occur at any age but are most common in the early teen-age years. Most occur in the middle of long bones of the legs or arms, unlike osteosarcoma, which usually occurs at the ends of the bones. Tumors can also occur in the pelvic bones or in the chest near the ribs.

What Are the Key Statistics?

Only five percent of all childhood bone tumors are Ewing’s. About 150 children and adolescents are diagnosed with a tumor of the Ewing’s family (TEF) in the US each year. Two-thirds will be long-term survivors (more than five years). Scientists have found only a few factors related to the risk of developing a TEF; however, more tumors occur in males than in females, and 64 percent occur in those between ages 10 and 20 years. More than 80 percent of the patients are white.

A tumor is described by size, where it originated, and whether it has spread. This is called staging. A TEF is staged as either localized (involving only the site of origin and nearby tissues) or metastatic (involving spread to distant parts of the body).

Survival rates have greatly improved since chemotherapy has been used to treat patients. If the tumor is localized in one area, less than four inches (10 centimeters), and can be removed by the surgeon, the 5-year survival rate is 80 percent or better when radiation therapy and chemotherapy are used after surgery. If the tumor cannot be removed but is still small, the survival rate is better than 70 percent. If, however, the tumor is large and cannot be removed, the 5-year survival rate is probably less than 60 percent, even if there is good response to chemotherapy and radiation therapy. When metastatic disease is present at diagnosis, the 5-year survival rate is less than 30 percent.

Diagnosing Ewing’s Sarcoma

At this time unfortunately, there are no special tests that can help with early detection of Ewing’s and PNET.

The most often described of the EFT is usually a lump on the trunk with or without pain. Sometimes there may be increased heat over the lump, and in some instances the child may have general symptoms, such as fatigue or stomach aches, and not feel well. Unfortunately, children have many, many lumps which can be painful due to normal play activities, so unless the lump persists for a prolonged period of time, there should be no cause for concern. If the lump is warm to the touch, and/or the child has fever, the child should be seen by a health professional.

The diagnosis of a TEF begins with recognition of certain signs and symptoms suggesting the disease might be present. The most common symptom of a TEF of the bone is pain. Pain occurs in about 85 percent of patients. The pain may be caused by the spread of the tumor under the periosteum (tissue covering the bone). Or the pain may be from a fracture (broken bone) in a bone that has been weakened by the tumor. Because these signs and symptoms are also typical of normal bumps and bruises or bone infections, some cases are not easily recognized. Only after the child’s condition does not resolve quickly or is not improved by antibiotics is the diagnosis questioned.

Treating Ewing’s Sarcoma

The goals of treating a tumor of the Ewing’s family are to cure the patient and to maintain as much function as possible. To achieve these goals, a multidisciplinary team approach is necessary. Surgeons, pediatric oncologists, radiation oncologists, pathologists, psychosocial specialists, and rehabilitation specialists must work together to give children and adolescents the best treatment and quality of life possible. This can be best accomplished at a children's cancer center that is a member of a cooperative pediatric cancer group.