This thesis focuses on the use of population-based data to provide more insight into the outcomes of patients with esophagogastric cancer treated in daily clinical practice. A large part of this thesis is based on data from the nationwide Netherlands Cancer Registry that covers the total Dutch population. Part I of this thesis focuses on patients in the curative setting and includes two studies that provide information on communication of life expectancy by providing conditional relative survival results and survival according to multiple scenarios of patients with non-metastatic esophagogastric cancer. In addition, a study is included that provides real-world outcomes of patients with esophageal- or gastroesophageal junctional cancer selected on the inclusion criteria of CheckMate 577. Part II of this thesis focuses on patients in the palliative setting and begins with a study that provides information on survival according to multiple scenarios of patients with metastatic disease. Additionally, an overview of treatment patterns and outcomes is provided for patients with esophageal squamous cell carcinoma as well as a comparison of adenocarcinoma by primary tumor location of the esophagus, gastroesophageal junction and stomach. Lastly, two studies provide insights on treatment and outcome after previous treatment with curative intent for non-metastatic disease, that is disease recurrence after esophageal or gastroesophageal junction cancer and a comparison of synchronous versus metachronous metastatic esophagogastric cancer.