Ewing's sarcoma

Ewing's sarcoma is a type of cancer that forms in bone or soft tissue. Symptoms may include swelling and pain at the site of the tumor, fever, and a bone fracture. The most common areas where it begins are the legs, pelvis, and chest wall. In about 25% of cases, the cancer has already spread to other parts of the body at the time of diagnosis. Complications may include a pleural effusion or paraplegia. Ewing's sarcoma is a type of cancer that forms in bone or soft tissue. Symptoms may include swelling and pain at the site of the tumor, fever, and a bone fracture. The most common areas where it begins are the legs, pelvis, and chest wall. In about 25% of cases, the cancer has already spread to other parts of the body at the time of diagnosis. Complications may include a pleural effusion or paraplegia. The cause of Ewing's sarcoma is unknown. Most cases appear to occur randomly. It is sometimes grouped together with primitive neuroectodermal tumors, in a category known as the Ewing family of tumors. The underlying mechanism often involves a genetic change known as a reciprocal translocation. Diagnosis is based on biopsy of the tumor. Treatment often includes chemotherapy, radiation therapy, surgery, and stem cell transplant. Targeted therapy and immunotherapy are being studied. Five year survival is about 70%. A number of factors, however, affect this estimate. James Ewing in 1920 established that the tumor is a distinct type of cancer. It affects about one in a million people per year in the United States. Ewing's sarcoma occurs most often in teenagers and young adults and represents 2% of childhood cancers. Caucasians are affected more often than African Americans or Asians. Males are affected more often than females. Ewing's sarcoma is more common in males (1.6 male:1 female) and usually presents in childhood or early adulthood, with a peak between 10 and 20 years of age. It can occur anywhere in the body, but most commonly in the pelvis and proximal long tubular bones, especially around the growth plates. The diaphyses of the femur are the most common sites, followed by the tibia and the humerus. Thirty percent are overtly metastatic at presentation. People usually experience extreme bone pain. Rarely, it can develop in the vagina. Signs and symptoms include: intermittent fevers, anemia, leukocytosis, increased sedimentation rate, and other symptoms of inflammatory systemic illness. According to the Bone Cancer Research Trust (BCRT), the most common symptoms are: localized pain, swelling, and sporadic bone pain with variable intensity. The swelling is most likely to be visible if the sarcoma is located on a bone near the surface of the body, but when it occurs in other places deeper in the body, like on the pelvis, it may not be visible. Genetic exchange between chromosomes can cause cells to become cancerous. Most cases of Ewing's sarcoma (85%) are the result of a translocation between chromosomes 11 and 22, which fuses the EWS gene of chromosome 22 to the FLI1 gene of chromosome 11. EWS/FLI functions as the master regulator. Other translocations are at t(21;22) and t(7;22). Ewing's sarcoma cells are positive for CD99 and MIC2, and negative for CD45.