Unusual sites of Ewing sarcoma (ES): A retrospective multicenter 30-year experience of the Italian Association of Pediatric Hematology and Oncology (AIEOP) and Italian Sarcoma Group (ISG)

Abstract Purpose The aim of this study was to describe the Italian Association of Pediatric Hematology and Oncology (AIEOP) and Italian Sarcoma Group (ISG) experience from 1980 to 2009 on 112 patients with Ewing sarcoma (ES) occurring in unusual sites such as the craniofacial bones (CF), hands or feet (HF), or the mobile spine. These sites were grouped because their rarity as ES localisations. Patient and methods Twenty-six patients had CF ES (23%), 37 patients had HF ES (33%) and 49 patients had mobile spine ES (44%). A total of 26 patients presented with synchronous metastatic disease (23%). The local treatment with surgery and/or radiotherapy differed among ES sites. Systemic therapy was administrated according to the protocols in use over the years. Results From the data available, the histological/radiological response was higher for HF-patients even not statistical significant (good responders: CF 41%, HF 65% and mobile spine 39%, P = 0.NS) and the probability of achieving complete response was similar among the three sites (CF 87%, HF 83% and spine 74%, P = 0.44). Ten year overall survival (OS) was 61% (95% confidence interval [CI] 39–82), 63% (95% CI 37–89) and 64% (95% CI 49–79) for CF, HF or vertebral ES, respectively ( P = NS). Ten year OS for non-metastatic patients was 60% (95% CI 36–83), 75% (95% CI 56–94) and 67% (95% CI 47–89) for CF, HF and mobile spine patients respectively ( P = NS). Ten year OS was 45% (95% CI, 31–84) and 70% (95% CI, 61–85, [ p = 0.01]) for metastatic and localised ES, respectively. Conclusions The probability of successful treatment did not differ from ES of the extremities. Furthermore, our series confirm the poor prognosis for patients with metastatic disease. Our data do not strengthen the need for a specific protocol for unusual site ES.