Background and purposeNeoadjuvant (NRTX) and adjuvant radiotherapy (ARTX) reduce local recurrence (LR) risk in extremity soft tissue sarcoma (eSTS), yet their impact on distant metastasis (DM) and... Show moreBackground and purposeNeoadjuvant (NRTX) and adjuvant radiotherapy (ARTX) reduce local recurrence (LR) risk in extremity soft tissue sarcoma (eSTS), yet their impact on distant metastasis (DM) and overall survival (OS) is less well defined. This study aimed at analysing the influence of NRTX/ARTX on all three endpoints using a retrospective, multicentre eSTS cohort.Materials and methods1200 patients (mean age: 60.7 ± 16.8 years; 44.4 % females) were retrospectively included, treated with limb sparing surgery and curative intent for localised, high grade (G2/3) eSTS. 194 (16.2 %), 790 (65.8 %), and 216 (18.0 %) patients had received NRTX, ARTX and no RTX, respectively. For the resulting three groups (no RTX vs. NRTX, no RTX vs. ARTX, NRTX vs. ARTX) Fine&Gray models for LR and DM, and Cox-regression models for OS were calculated, with IPTW-modelling adjusting for imbalances between groups.ResultsIn the IPTW-adjusted analysis, NRTX was associated with lower LR-risk in comparison to no RTX (SHR [subhazard ratio]: 0.236; p = 0.003), whilst no impact on DM-risk (p = 0.576) or OS (p = 1.000) was found. IPTW-weighted analysis for no RTX vs. ARTX revealed a significant positive association between ARTX and lower LR-risk (SHR: 0.479, p = 0.003), but again no impact on DM-risk (p = 0.363) or OS (p = 0.534). IPTW-weighted model for NRTX vs. ARTX showed significantly lower LR-risk for NRTX (SHR for ARTX: 3.433; p = 0.003) but no difference regarding DM-risk (p = 1.000) or OS (p = 0.639).ConclusionNRTX and ARTX are associated with lower LR-risk, but do not seem to affect DM-risk or OS. NRTX may be favoured over ARTX as our results indicate better local control rates. Show less
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
