Local control and sequelae in localised Ewing tumours of the spine: a French retrospective study.

Objectives: To evaluate both local outcome and sequelae of non-metastatic spinal Ewing tumours (EWT).

Patients And Methods: A French cohort of patients ≤ 50years with localised spinal EWT treated between 1988 and 2009, was analysed in regard to tumour characteristics (e.g. volume, vertebral compartment, spinal cord compression, paraspinal soft tissue invasion), local treatment modalities (surgery (S) and margin quality, radiotherapy (RT) dose), response to treatment (e.g. histological response to neoadjuvant chemotherapy (CT)), tumour local control (LC) and sequelae.

Results: Seventy-five patients treated in successive trials were evaluated for LC: SFOP-EW88 (n=14), SFOP-EW93 (n=17) and EuroEwing99 (n=44). Fifty-seven patients (79%) presented initial neurological compression and 69% had inaugural decompressive S. Local treatment modality was S+RT (n=50), RT alone (n=19) and S alone (n=6). Surgery was mainly intralesional (66%). Local recurrences had occurred in 19 patients (14 local, 5 loco-regional) with a median interval of 25 months (1-50). After a 7 year median follow-up (1-22 years), the 5-year LC, relapse-free survival (RFS) and overall survival (OS) reached 78.0% (95%CI: 62.6-84.6), 57.0% (95%CI: 45.2-68.9) and 70.0% (95%CI: 59.1-81.0), respectively. Vertebral compartment involved was the only prognostic factor (5-year LC rate 100% versus 71% for favourable and unfavourable compartment, p<0.03). Among 41 five-year survivors, we observed spinal curvature deformation (35%), growth retardation (28%), spinal reduction mobility (40%), spinal pain (25%) and neurological sequelae (32%) without any significant association with a particular local procedure.

Conclusion: RT is the backbone of a successful local treatment of spinal EWT. The place of S remains a pending question. Its actual benefit will likely evolve with new available RT techniques.