Prognostic factors for patients with Ewing sarcoma (EWS) at first recurrence following multi-modality therapy: A report from the children's oncology group

Background. The prognosis for patients with recurrent Ewing sarcoma (EWS) is very poor with 5-year survival of 13%. Methods. To evaluate prognostic factors for these patients we studied patients initially treated on the multi-institutional study INT0091. Results. Two hundred sixty-two patients experienced disease recurrence. The median time to first recurrence was 1.3 years (0-7.4 years), 1.4 years (0-7.4 years) for patients with initially localized disease and 1 year (0-6 years) for patients with initially metastatic disease. Time to first recurrence from date of initial diagnosis was a predictor of post-recurrence survival (P < 0.0001). Twenty-one percent of patients, with recurrent or progressive disease ≥2 years from initial diagnosis, had an estimated 5-year survival of 30% (vs. 7% estimated 5-year survival with an earlier recurrence). No statistical difference was detected between patients whose disease recurred <1 year and between 1 and 2 years from initial diagnosis. A stepwise relative risk model and backwards stepwise regression was used to explore factors significantly associated with risk for post-recurrence death. Significant risk factors for death after recurrence included recurrence at combined local and distant sites, elevated LDH at initial diagnosis and initial recurrence less than 2 years after diagnosis. Isolated pulmonary recurrence was not predictive of survival after recurrence. Conclusion. Patients with a longer disease control interval represent the subset of patients most likely to survive following recurrence of EWS. All patients with recurrence would benefit from collaborative trials to investigate new therapeutic options.