Around 5 to 25% of lung cancer worldwide occurs in lifelong non-smokers (less than 100 cigarettes in lifetime). Lung cancer in never smokers (LCINS) shows many clinical, epidemiological and molecular differences compared to those related to tobacco. It is therefore often considered as a separate entity. LCINS is also a good model for the study of lung cancer risk factors and tumoral mutation profiles (usually more common and specific). However, most data has come from retrospective studies and/or from Asian populations, although this disease shows high geographic lability. The BioCAST/IFCT-1002 is a national, multicentric, prospective study promoted by the French intergroup IFCT. The first objective is to describe the clinical and molecular epidemiology of LCINS in a French population. Detailed data (including exposure to many risk factors) are collected directly from the patient through a standardized questionnaire completed during a telephone interview. All patients also undergo blood sampling for the analysis of genomic polymorphisms and the characterization of epigenetic anomalies. BioCAST hopes to provide concrete answers for clinicians and patients about this entity.