Systemic treatment effectiveness in advanced esophagogastric cancer in clinical practice

This thesis includes studies that focus on the palliative treatment of patients with advanced esophageal and gastric cancer in daily clinical practice. Rather than curation, palliative treatment aims to prolong survival, optimize quality of life and reduce symptom burden. Most results regard palliative systemic treatment, which consists of either chemotherapy, targeted therapy or both. This thesis provides insights into the management of patients with advanced esophagogastric cancer in The Netherlands using data of the nationwide Netherlands Cancer Registry, supplemented with patient-reported outcomes of the Prospective Observational Cohort Study of Oesophageal-gastric Cancer Patients (POCOP). It sheds light on several factors that are associated with the allocation of palliative systemic treatment, e.g. gender, but also factors that are not patient or tumor-related, e.g. the number of patients diagnosed in a hospital annually. Practice variation in first-line and second-line palliative systemic treatment administration as well as in biomarker testing is described. Moreover, aspects that are associated with treatment outcomes, such as skeletal muscle mass and cachexia, are discussed. The real-world results provide an overview of the contemporary situation of palliative systemic treatment administration in esophagogastric cancer in clinical practice, and enabled to reveal differences between treatment effectiveness in clinical practice and treatment efficacy described in clinical trials.