Incidence of bone tumours

Most bone tumours encountered in clinical practice are secondaries (i.e. metastases from primary cancer that started elsewhere), and it is a layman’s misnomer to refer to these as ‘bone cancer’. The doctor reserves this term to those tumours of bone which arise in the bone ab initio. The point is of importance as the methods and data outlined below do not apply to bone secondaries/metastases.

 

Primary bone tumours include osteogenic sarcoma (arising from the true bone forming cell) Ewing’s sarcoma (arising from a primitive pluripotential cell) and chondrosarcoma (arising from the cartilage forming cell line); primary bone lymphoma will not be considered here , nor the occurrence of sarcomas which are more commonly associated with soft tissues (e.g. malignant fibrous histiocytoma) – see Soft Tissue Sarcoma Section.

 

Osteogenic sarcoma occurs with two peak incidences in life: the first is in adolescence (when the bones are actively growing) and the second is in late life and not infrequently associated with Paget’s disease of bone. Exposure to radiation predisposes to the later development of osteogenic sarcoma, and some patients with familial syndromes (par excellence those with hereditary retinoblastoma – but see introductory remarks concerning soft tissue sarcomas for others) are predisposed.

Ewing’s sarcoma tends to present in youth whereas chondrosarcomas, whilst certainly afflicting the young also is more common in later life.