Bone sarcomas: ESMO-PaedCan-EURACAN Clinical Practice Guidelines for diagnosis, treatment and follow-up
Abstract
Primary bone tumours are rare, accounting for 25 years old, ES has an incidence of 0.3 per 100 000 per year, and it is even rarer in the African and Asian population. The genetic basis for the difference between ethnical groups has been recently linked to a common genomic germline variant, which extends a microsatellite, thereby facilitating the binding of the EWSR1-FLI1 chimeric protein to the EGR2 gene locus, leading to higher expression of the transcription factor early growth response 2 (EGR2) and increased susceptibility to ES.
The most common ES primary sites are the extremity bones (50% of all cases), followed by pelvis, ribs and vertebra. However, any bone can potentially be affected and a soft tissue origin is also possible, especially in adults (30% of cases).
Chordomas are even rarer compared with other subtypes, with an incidence of 0.5 per million per year. High-grade spindle/pleomorphic sarcomas of bone are a heterogeneous group of primary malignant bone tumours that do not fulfil the histological criteria for a diagnosis of OS, CS or ES.
Giant cell tumour (GCT) of bone is a benign, locally aggressive and rarely metastatic intramedullary bone tumour composed of mononuclear cells and osteoclast-like multinucleated giant cells, with a variable and unpredictable potential for aggressive growth. It represents 5% of primary bone tumours, with an incidence of approximately 1 per million per year.