This thesis describes several retrospective studies in mesenchymal tumours. Sarcomas are the malignant variant and are very rare with an incidence of approximately 1000 patients per year in the... Show moreThis thesis describes several retrospective studies in mesenchymal tumours. Sarcomas are the malignant variant and are very rare with an incidence of approximately 1000 patients per year in the Netherlands divided over more than 50 subtypes. It is essential to use the available patient data as much as possible.Due to its rarity, all stages of sarcomas are usually grouped in one study. This thesis shows that patients with distant metastatic disease have a worse prognosis compared to patients with locally advanced disease. To improve the prognosis of sarcoma patients, maintenance treatment after first line doxorubicin treatment is currently considered. However, we show that only 33% of the patients qualifies for maintenance treatment. Patients that qualify for maintenance treatment have a significantly better prognosis than all doxorubicin treated sarcoma patients.Further, this thesis describes several rare side effects and treatment for this side effect of treatment in mesenchymal tumours and it reports the incidences of giant cell tumours of bone and gastro-intestinal stromal tumours . It also studies the outcomes of non-surgical treatment options for desmoid-type fibromatosis. Last, the outcomes of ifosfamide treatment as second line treatment for osteosarcoma are reported. Show less
