Survival of patients with colorectal cancer improved markedly over the past decades, as a result of advances in screening, staging procedures, treatment, and surveillance. However, still about 20%... Show moreSurvival of patients with colorectal cancer improved markedly over the past decades, as a result of advances in screening, staging procedures, treatment, and surveillance. However, still about 20% of patients with colorectal cancer develop metachronous metastases and 20% of all patients with colorectal cancer have metastatic disease at diagnosis. Several treatment modalities, such as total mesorectal excision (TME) and preoperative (chemo)radiotherapy for rectal cancer, as well as adjuvant chemotherapy for stage III colon cancer, have been studied extensively and showed to improve cancer-related outcomes. On the contrary, the effectiveness of other treatment modalities including adjuvant chemotherapy for rectal cancer and for stage II colon cancer, and surgery of the primary tumour in incurable metastatic colorectal cancer are still subject of debate. Moreover, there is considerable short-term and long-term morbidity after (chemo)radiotherapy or surgery which should be taken into account. Further defining optimal treatment strategies is therefore of great importance. This thesis focused on improving evidence for treatment modalities that are currently subject of debate for patients with colorectal cancer. This was done using data from randomised controlled trials as well as cancer registry data. Show less
The aim of this thesis was to answer currently unanswered questions regarding health-related quality of life (HRQoL) in glioma patients by undertaking powerful detailed secondary analyses of... Show moreThe aim of this thesis was to answer currently unanswered questions regarding health-related quality of life (HRQoL) in glioma patients by undertaking powerful detailed secondary analyses of existing pooled individual HRQoL patient data, which was previously collected in 15 RCTs in glioma patients.In total, data of 6048 glioma patients was included in the CODAGLIO database and 5 manuscripts were written that provide relevant information both for clinical practice as well as for clinical trials. Results of these studies entailed information on the added prognostic value of HRQoL at baseline in predicting survival. Furthermore, symptom clusters were identified and their association with functioning was investigated, and the impact of both (progression of) the disease and treatment on HRQoL deterioration was studied. Moreover, the ‘net clinical benefit’, weighing HRQoL and survival was calculated and different analytical methods to calculate change in HRQoL were compared.The CODAGLIO project, the largest individual patient data (IPD) project in neuro-oncology research so far, showed to represent an unique opportunity for secondary hypothesis testing, to answer clinically relevant questions with respect to HRQoL. Show less
The main objective of this thesis was to determine the value of dialysis and conservative care for older patients with advanced chronic kidney disease. To do so, we compared a combination of... Show moreThe main objective of this thesis was to determine the value of dialysis and conservative care for older patients with advanced chronic kidney disease. To do so, we compared a combination of patient-relevant outcomes and treatment costs in a cohort of older patients (≥70 years old) who chose either dialysis or conservative care after a shared decision-making process. Overall, we observed that older patients who chose dialysis lived longer compared with older patients who chose conservative care. There was, however, little or no significant survival advantage in patients aged ≥80 years old and patients aged ≥70 years old with severe comorbidity who chose dialysis over conservative care, while similar outcomes on quality of life and symptoms were observed between both patient groups, and lower treatment burden and treatment costs were observed in patients who chose conservative care. Therefore, we conclude that conservative care is a viable treatment alternative to dialysis in selected older patients. In clinical practice, conservative care needs to become available and openly discussed as one of the possible treatment pathways for advanced chronic kidney disease in older patients. Moreover, a shift towards a person-centered process of shared decision-making is needed that aims to focus on all that matters to the patient as person, in order to come to a treatment plan that fits best with the patient. Show less
