PhD Defence Koen de Nijs

Most lung cancer cases are detected only after the disease has spread to other organs. At this advanced stage, survival remains low—28% after one year—even with new treatments. Earlier detection through CT screening has been shown in large trials to find cancers sooner and reduce lung‑cancer mortality by 24%. However, it was still unclear how these trial results would translate into population‑level costs and health benefits.

The thesis uses microsimulation modelling to project real‑world outcomes at the national level. It estimates the costs of a large‑scale screening program and the number of life‑years that could be gained. The study addresses key questions raised by the Health Council in 2025, such as which risk metrics should determine eligibility,, the optimal screening ages, and whether annual or biennial screening is most effective.

For the Netherlands, screening high‑risk individuals aged 55–75 could prevent around 1,000 deaths per year—about 10% of current lung‑cancer mortality—at an estimated €12,000 per life‑year gained, within acceptable national cost‑effectiveness thresholds. Personalized risk scores could further improve efficiency by adjusting the age of first screening based on individual risk levels. Moreover, the thesis shows that the onset of expensive treatments for late-stage lung cancer have made early detection increasingly cost-efficient.