Localized Adult Ewing Sarcoma: Favorable Outcomes with Alternating Vincristine, Doxorubicin, Cyclophosphamide, and Ifosfamide, Etoposide (VDC/IE)-Based Multimodality Therapy.

BACKGROUND: In children with localized Ewing sarcoma (ES), addition of ifosfamide and etoposide to cyclophosphamide, doxorubicin, and vincristine (VDC/IE) improved 5-year overall survival (OS) to 70%-80%. Prior to delivery of VDC/IE in adults, 5-year OS was <50%. We reviewed our institutional outcomes for adults with ES who received VDC/IE-based treatment.

MATERIALS AND METHODS: Between 1997-2013, 67 adults with localized ES were treated with curative intent. Local recurrence-free survival (LRFS), progression-free survival (PFS), and OS were determined using Kaplan-Meier method; comparisons were assessed with log-rank. Proportional hazard models were used to determine predictive factors.

RESULTS: All patients received VDC/IE (median 14 cycles.) Local therapy was surgery for 33, radiation therapy for 17, or both for 17. Median follow-up for living patients was 5.2 years. Six patients had disease progression on therapy. Site of first failure was local for three, local and distant for two, and distant for ten. Five-year LRFS was 91%; 5-year LRFS was 96% for nonpelvic disease and 64% for pelvic disease ( p  = .003). Five-year PFS was 66%, and 5-year OS was 79%. On multivariate analysis, pelvic site had a 3.3 times increased risk of progression ( p  = .01).

CONCLUSION: Survival for adults with localized ES treated with VDC/IE-based multimodality therapy appears to be better than historical data and similar to excellent outcomes in children. Pelvic site of disease remains a predictor of worse outcome. Given the paucity of literature for adult ES, these data help validate VDC/IE-based therapy as an appropriate treatment approach for this rare disease in adults.

IMPLICATIONS FOR PRACTICE: Ewing sarcoma (ES) is rare in adults. Treatment approaches for adults have been extrapolated from the pediatric experience, and there is a sense that adults fare less well than children. We reviewed treatment outcomes in adults with localized ES treated with cyclophosphamide, doxorubicin, and vincristine in alternation with ifosfamide and etoposide (VDC/IE) as part of multimodality therapy. Survival outcomes appear to be better than historical data for adults and similar to the excellent outcomes for children. These data help validate VDC/IE-based therapy as an appropriate treatment approach for this rare disease in adults.