Early Detection of Lung Cancer With Machine Learning Based on Routine Clinical Investigations

All patients: * Age ≥ 50 years and \< 80 years at the index date of diagnosis (for Cases) or pseudodiagnosis (for Controls). * Presence of at least one extended blood analysis, spirometry and DLCO report within the 6 months before the index date. * Chest CT scan performed in a non-urgent setting (electively) within the 6 months before the index date (= index CT). * Active smokers at the index date or former smokers that ceased smoking within 15 years before the index date. * Smoking history ≥ 20 pack-years. Additional for Cases only: Confirmed histological diagnosis of bronchogenic lung cancer in the time period ≥ 2010 and ≤ 2020. Additional for Controls only: * Absence of lung cancer at all times ≤ 2020, confirmed by chest CT scan at the index date. * Documented to live without diagnosis of lung cancer for at least 3 years after the index date. Extended criteria for the lung cancer prediction subgroup: In addition to the above stated inclusion criteria, patients in this subgroup have at least one extended blood analysis, spirometry and DLCO report available in the time interval between 3-5 years before the index date.