Clinical approach towards bone sarcoma care

Abstract

For over two decades now, bone sarcoma care has been centralised in the Netherlands. To obtain a clear picture, it is important to evaluate the way we treat these patients. The studies in this thesis are structured around three themes: bone sarcoma incidence, the impact of centralisation and follow-up. In the first part of this thesis, a nationwide registry study provided comprehensive incidence estimates for all main primary bone sarcomas in collaboration with the Netherlands Cancer Registry. Furthermore, a rare chondrosarcoma subtype was described. In the second part of this thesis, a retrospective single bone sarcoma centre study quantified time to diagnosis and its effect on clinical outcome in high-grade bone sarcoma. Moreover, a cross-sectional study described the organisation of care in several European bone sarcoma centres. In the third part of this thesis, a European cross-sectional study analysed follow-up procedures. Finally, a nationwide registry study evaluated the oncological events occurring after index treatment with curative intent during follow-up. Main finding of this thesis - As a result of centalisation, treatment in a bone sarcoma centre of high-grade osteosarcoma patients resulted in improved survival- Prolonged delay in diagnosis does not result in lower survival probably due to more aggressive tumour behaviour, which results in shorter delays. - Sufficient evidence is lacking to determine a treatment threshold for a bone sarcoma centre - A plateau in new local recurrences and distant metastatic events after four years of treatment for patients with high-grade osteosarcoma and Ewing sarcoma was seen during follow-up.