Ewing sarcoma of the mobile spine; predictive factors for survival, neurological function and local control. A Scandinavian sarcoma group study with a mean follow-up of 12 years

Object: Many patients with Ewing sarcoma (ES) of the mobile spine present with neurologic symptoms leading to emergency decompressive surgery. Only rarely is optimal treatment involving neo-adjuvant chemotherapy followed by en bloc excision possible. The purpose of this study was to study treatment, neurologic and oncologic outcome in patients with ES of the mobile spine. Methods: Twenty-four patients diagnosed between 1986 and 2012 were identified through the Scandinavian Sarcoma Group registry. Charts were reviewed in order to assess details in patient characteristics, neurologic status, treatment and outcome. Prognostic factors were analyzed with respect to local control, disease-free survival and overall survival. Results: Neurologic symptoms were frequently observed at presentation, being present in 19/23 patients with documented neurologic status. Most (13/19) patients had a complete neurologic recovery regardless of whether or not emergency decompressive surgery was performed. The majority (18/24) of patients were treated with definitive radiotherapy. However, only 9/17 received the recommended dose of ≥ 50.4 Gy. The disease-free and overall survival rates at 10 years were 48% and 57%, respectively. The local recurrence rates were 19% and 27% at 5 and 10 years, respectively. Only year of diagnosis, categorized into periods with significant changes in chemotherapy protocols, was a significant factor for local recurrence, but there was a trend (p = 0.06) for an increased risk of a local recurrence if emergency decompressive surgery was performed. Conclusion: Patients with ES of the mobile have a relatively favorable prognosis. Nonetheless, local recurrence rate is high for this group of patients for which local treatment mainly relies on definitive radiotherapy. Emergency decompressive surgery may increase the risk for local recurrence.