Ewings Sarcoma Wheeless

Description: Discussion: - prevalence: - it represents approx 7% of all primary bone malignancies; - Ewing's sarcoma is more common in males and is rare in blacks; - source: - uncertain origin; - may arise from primitive reticulum cells of marrow; - common karyotypic translocation between chromosomes 11 and 22; - age: - it is a tumor of children & young adults, w/ most cases occurring between ages of 10 and 20 years; - 3% of Ewing's sarcoma occurs in children less than 3 years of age; - 64% of Ewing's sarcoma occur in the second decade; - genetics: - expresses p30/32 MIC2 antigen (cell surface glycoprotein); - 85% contain chromosomal translocation at the t(11;22)(q24;q12); - prognosis: - potentially the most lethal of all the bone tumors; - most important adverse prognostic factor was metastatic disease detectable at the time of diagnosis; - it almost always presents as a stage IIb lesion; - before routine use of adjuvant chemo, pts w/ Ewing's were treated w/ XRT alone, & 5 year survival rate was no more than 15%; - w/ use of adjuvant chemo, 5 year survival rate to more than 60%; - w/ non metastatic Ewing's, disease free survival is 55-70% versus 22-33% for metastatic; - pts require careful follow-up, due to post-XRT osteosarcoma