Treatment of ewing sarcoma, paediatric bone sarcomas and severe paediatric spinal deformities in Finland

Background: Ewing sarcomas are rare highly malignant tumours. There are not many population-based studies including both bone and soft tissue tumours. Previous reports have suggested that the incidence of Ewing sarcoma in the paediatric population may be lower in Northern Europe compared to other parts of Europe. Ewing sarcomas frequently arise in the pelvis and other axial sites and rarely in the spine. Surgical techniques of vertebral column resection to treat spinal tumours or severe spinal deformities have evolved with techniques using only a posterior approach. Aims: Our aim was to find out how the treatment of Ewing sarcoma is carried out in Finland and what are the five-year survival rates and to reveal the surgical treatment and its complications. We also aimed at establishing the incidence rates of bone sarcomas in the paediatric and adolescent population in Finland and to establish the ten-year survival rates. Additionally, we aimed to report the results of a population-based material on paediatric vertebral column resection. Material and methods: We identified all Finnish patients with Ewing sarcoma diagnosed during 1990-2009, all paediatric bone sarcoma patients diagnosed during 1991-2005 and all paediatric patients who underwent vertebral column resection during 2005-2009. The medical records were reviewed for detailed information and these data were analysed. The study is retrospective, nationwide and population-based. Results: Seventy-six Ewing sarcoma patients were included in the final analyses. The five-year sarcoma-specific survival rates were 70% for those with localized and 33% for those with metastatic disease (p=0.001). Fifty-seven patients underwent surgical treatment of the primary tumour. The annual incidence rates of osteosarcoma, Ewing sarcoma and chondrosarcoma per million 0-18-year-old people in Finland during 1991-2005 were 3.6, 1.2 and 0.3, respectively. The ten-year overall survival was 74% for osteosarcoma, 76% for Ewing sarcoma and 80% for chondrosarcoma. Fourteen paediatric patients underwent vertebral column resection during 2005-2009. There were no differences between those operated via posterior-only approach (n=7) compared to those operated via antero-posterior approach (n=7) in the mean final radiological corrections or the quality-of-life results. Conclusions: We conclude that the outcomes of treatment of Ewing sarcoma and paediatric bone sarcomas in Finland are comparable to previously reported outcomes. The incidence of Ewing sarcoma in Finland seems to be a bit lower than reported elsewhere in Europe. Posterior-only approach in paediatric vertebral column resections carry comparable results to anteroposterior approach.