Sarcomas are malignant tumors of the body’s soft tissues, such as fat, muscles, nerves, tendons, and blood and lymph vessels. Soft-tissue sarcomas are uncommon.  According to the American Cancer Society, approximately 8,300 new cases of soft-tissue sarcoma will be diagnosed in the United States in 2003 (source).

One type of sarcoma is Ewing’s family of tumors.  Cancers in the Ewing’s family of tumors are made of primitive cells, which are cells that haven’t yet decided what type of cell they are. They look blue due to the staining so the cells are referred to as small round blue cells.

The Ewing’s family of tumors include:

• Ewing’s tumor of bone
• Extraosseus Ewing’s (tumor growing outside of the bone)
• Primitive neuroectodermal tumor (PNET), also known as peripheral neuroepithelioma.
• Askin’s tumor (PNET of the chest wall).

All of these are frequently referred as to Ewing’s sarcoma in the popular and medical literature.

90% of Ewing’s sarcoma tumors occur in bones, leaving 10% of them to occur in soft tissues (source for 87% in bone). Currently, the treatments of both soft tissue and bone tumors are the same. There are 200 cases new cases diagnosed in children and adolescents in the US per year (source), and 20 diagnosed in adults (source; source).

The prognosis of Ewing’s sarcoma is dependant on state of the disease at diagnosis and the response to the standard protocol. Other factors are important (age, location of tumor, margins after resection, etc.).

Overview papers

• A good overview article on Ewing’s sarcoma (by the Loyola University Health System).
• Comprehensive article; it describes several of the chemo drugs (from emedicine.com).
• Cancer Index FAQ on Ewing’s.
• NCI’s Questions and Answers about bone cancer.
• Washington Musculoskeletal Tumor Center web pages.

Treatment

Many clinical trials have been performed on children, so the treatment is quite standardized. Ewing’s is considered a systemic disease, i.e., there are cancer cells throughout the body which might not be able to be detected (source). The treatment for Ewing’s is aggressive; it is normally 9-12 months long, and can consist of 10-14 cycles of chemotherapy, resection surgery to remove the primary tumor, and radiation to the local site.

Sometimes, the first line treatment isn’t enough. Possible reasons are the primary tumor continues to grow, the biopsy of the resected tumor shows little necrosis (i.e., a low percentage of cells that are dead), metastases develop, or a local recurrence.