The goal of this observational study is to improve the early detection of lung cancer in adults who have smoked less than 100 tobacco cigarettes (never-smokers) in the United Kingdom. The main questions it aims to answer are: * To describe characteristics such as demographics, co-morbidities and environmental exposures * To describe participant pathways including presentation mode and symptoms to understand if earlier diagnosis would be possible * To describe participant outcomes such as cancer stage, treatment and mortality * To quantitatively or qualitatively measure modifiable and non-modifiable factors that may be associated with LCINS including environmental measures, blood tests and genomic data. Participants will currently have no change to their usual care.