Purpose: This retrospective analysis describes our 35-year experience with respect to disease control and functional status.
Patients and methods: Thirty-five patients with localized Ewing tumors of the pelvis and sacral bones were treated from 1970 to 2005. Twenty-six patients were treated with definitive radiotherapy (RT), and 9 patients were treated with combined local therapy in the form of surgery + RT. The median RT dose was 55.2 Gy. The patients who received RT alone were more likely to be older men with larger tumors exhibiting soft-tissue extension. Patients in the definitive RT group were more likely to receive etoposide and ifosfamide or undergo bone marrow transplant. Median potential follow-up was 19.4 years.
Results: The 15-year actuarial cause-specific survival, freedom from relapse rate, and local control rates were 26% vs. 76% (p = 0.016), 28% vs. 78% (p = 0.015), and 64% vs. 100% (p = 0.087), respectively, for patients treated with definitive RT and combined therapy. Overall, tumors <8 cm had significantly better cause-specific survival, but this was unrelated to local control. The median Toronto Extremity Salvage Score for the definitive RT and combined therapy groups were 99 and 94, respectively (p = 0.19). Seven definitive RT patients (27%) had serious complications.
Conclusion: Combined modality local therapy should be considered if pelvic Ewing tumors are resectable. However, because of the extent of local disease, most patients have unresectable or partially resectable tumors and therefore require RT in some capacity. For this reason, innovative RT strategies are needed to improve long-term disease outcomes and minimize side effects while maintaining an acceptable functional result.