Prognostic significance of histopathologic response to chemotherapy in nonmetastatic Ewing's sarcoma of the extremities.

Abstract

PURPOSETo evaluate more accurately the effectiveness of preoperative chemotherapy in the treatment of patients with Ewing's sarcoma, we studied histopathologically the chemotherapeutic response and correlated it to oncologic outcome.PATIENTS AND METHODSBetween June 1983 and December 1989, 68 patients with nonmetastatic Ewing's sarcoma of the extremities were treated at our institute with preoperative chemotherapy (without radiation therapy) and surgery. The specimens were retrospectively evaluated for areas of viable tumor cells and graded from I to III (macroscopic, microscopic, or no residual disease, respectively) in a blinded fashion. Clinical follow-up data were available on all patients for a mean of 60 months (range, 32 to 111).RESULTSThis histopathologic analysis was strongly correlated with oncologic outcome (P = .004). Patients who demonstrated grade III response (no identifiable viable tumor nodules present) had improved 5-year disease-free survival rates as compared with patients with grade II...