Ewing's sarcoma of the mobile spine.

OBJECTIVES: To evaluate the role of enbloc resection on the oncological outcome of patients with Ewing's sarcoma of the mobile spine treated with systemic multiagent chemotherapy combined with radiation therapy. While the role of chemotherapy and radiation therapy is well known and accepted in the treatment of Ewing sarcoma, there is no consensus on the role of enbloc resection in those tumors occurring in the mobile spine and, therefore, it can be difficult to conclude the decision making process, particularly if to achieve a tumor-free margin resection functionally relevant structures should be sacrificed. The study design of this work was the retrospective analysis of a series of 27 cases of Ewing sarcoma of the mobile spine homogeneously treated.
METHODS: Twenty-seven patients with primary ES of the mobile spine were treated from 1979 to 2008 by the same multidisciplinary team. All the patients presented with pain. Motor deficits were present in 6 patients. All the patients were submitted to multiagent protocols of chemotherapy (always) and radiotherapy (alternative to surgery or associated to). Surgery was performed in 17 cases both for functional purpose (7 cases: intralesional piecemeal excision) both for curative purpose (10 cases: enbloc resection, resulting characterized by marginal/wide or intralesional margins). Patients were observed for a minimum of 2 years or until death. The mean follow-up time was 65 months (median 28 months; ranging 2 to 218 months). Neurological function, local recurrence, distant relapse, and treatment-related complications were evaluated.
RESULTS: Three periods were considered according to the evolution of therapeutic strategies. Four patients were treated in the period 1979 to 1982. All were submitted to chemotherapy (REA-2) and radiation therapy (RT). Two of them were submitted to intralesional excision. All these patients died 2 to 29 months later without significant difference in the two groups. In the period 1983 to 1990 all patients were treated with chemotherapy (REN-1/2) and RT. Two were submitted to intralesional excision and had a worse evolution as died of the disease at 2 and 11 months follow up, while the patients who did not received surgery evolved more favourably: 1 died of the disease 57 months after the end of the treatment, 3 are continuously disease free at 130, 190, 290 months. The sixteen patients treated in the period 1991 to 2008 received chemotherapy (REN-3 and ISG-SSG) and RT, combined with intralesional excision in 3, with enbloc with intralesional margins in 4, enbloc with tumor-free margins (wide or marginal) in 6. Only one patient submitted to tumor-free margin enbloc resection had local recurrence and died 29 months after the treatment (biopsy was performed by open approach), the other surviving continuously disease free at 17 to 193 months follow-up (av. 76 months). All the patients submitted to intralesional excision and to enbloc resection resulting in margin violation had the same prognosis, as died of the disease 10 to 63 months after the treatment. Only one of the 3 patients who had no surgery died of the disease 8 months after the treatment, the other surviving 9 and 49 months follow-up. Among the seven patients who had neurological symptoms at the occurrence, just those with no metastasis and who underwent enbloc resection are alive.
CONCLUSIONS: The current study seems to demonstrate that tumor-free margin enbloc resection provides better local control and longer survival, while the results after intralesional margin resection or piecemeal excision combined with chemotherapy and RT is less effective than chemotherapy and RT alone.