Outcome after relapse in an unselected cohort of children and adolescents with Ewing sarcoma.

Background: Survival after relapse in patients with Ewing sarcoma is very poor and this retrospective study attempts to identify of prognostic factors predicting survival after relapse.

Procedure: A total of 191 patients with localised Ewing sarcoma were registered in the ET-2 trial of the United Kingdom Children's Cancer Study Group (UKCCSG). All patients received standardised primary treatment with chemotherapy and surgery and or radiotherapy as local modality treatment. Sixty-four patients who relapsed are included in this report. Treatment at relapse was variable and included chemotherapy, surgery, radiotherapy and high dose therapy (HDT) or megatherapy with peripheral stem cell transplantation (PBSCT) or autologous bone marrow transplantation (ABMT) in various combinations. A subgroup of patients had only non-specific symptomatic treatment at relapse. Both univariate and multivariate methods were used to investigate variables affecting survival after relapse.

Results: The overall actuarial median survival from relapse for all patients was 14 months (95% CI 11-16 months). Univariate analysis showed that males had a longer survival (median, 16 months vs. 11 months); patients who relapsed while on treatment did worse (median, 3 months vs. 16 months) and patients who had a longer disease-free interval (DFI) prior to relapse had a better outcome (DFI <1 year, median survival = 3 months; DFI 1-2 years, survival = 8 months; DFI > 2 years, median survival = 24 months, P < 0.001). Multivariate analysis confirmed that duration of first remission was the only factor associated with longer survival after relapse.

Conclusions: These data suggest that although aggressive therapy may delay disease progression after relapse for some children, the course of the disease after relapse is usually fatal. International co-operative studies are needed to evaluate new strategies.