Prognosis and Outcome of Cervical Primary Extraosseous Intradural Extramedullary Ewing Sarcoma: A Systematic Review

Primary spinal extraosseous Ewing sarcoma (ES) is a rare mesenchymal tumor characterized by high malignancy, occurring in a few patients with ES. The occurrence of this tumor in the intradural extramedullary spinal region is infrequent. This systematic review examines primary extraosseous intradural extramedullary ES in the cervical region to provide specific outcomes and evaluate the role of adjuvant chemoradiation in overall prognosis. A systematic review was conducted to identify all cervical primary extraosseous intradural extramedullary ES reported in the literature. The search included the databases of PubMed, Google Scholar, Medline, Embase, and Scopus from inception to June 2021. Inclusion criteria include a reported death outcome or a minimum one-year follow-up. Our search retrieved 21 articles that involved the cervical spine, but only 11 cases met the inclusion criteria. Of the nine patients who demonstrated disease progression, six experienced local failure, two had distant craniospinal axis failure, and one had systemic metastases. Five patients died of the disease at a median of 11 months after diagnosis. Our analysis showed a one-, two-, and five-year progression-free survival (PFS) of 36.4%, 36.4%, and 12.1%, respectively. The one-, two-, and five-year overall survival rates were 72.7%, 62.3%, and 46.8%, respectively. Three of the five (60%) patients who died received craniospinal radiotherapy. Of the six patients who survived, two received craniospinal radiotherapy (33%), and one received whole spine radiotherapy (17%). This review showed that patients with cervical primary extraosseous intradural extramedullary ES had poor progression-free survival and overall survival rates. The addition of adjunct craniospinal radiotherapy did not improve the prognosis of these patients.