Real-world data in cancer treatment: Bridging the gap between trials and clinical practice

This thesis addressed how the real-world population of patients with cancer differs from the trial population and how real-world data can be used in daily clinical practice to improve cancer care. Quality registries are a source of real-world data on patients treated in clinical practice. These data can be used to improve care, for example, using quality indicators. This thesis describes different methods to compare real-world and trial patients and how these groups differ. We showed that 40% of the patients with advanced melanoma would be ineligible for trial participation because they are less fit and often have brain metastases. Furthermore, the adjuvant treatment of patients with melanoma is often early discontinued in clinical practice. In patients with advanced melanoma, we also found poorer survival outcomes in the real-world. These differences can mainly be explained by poorer patient- and tumor characteristics. Real-world data can be used in clinical practice to provide realistic treatment outcomes, perform exploratory analyses that clinical trials cannot fulfill, and describe cancer care in extraordinary settings such as the COVID-19 pandemic.