All the participants should complete a questionnaire that covers many topics, including demographic characteristics and smoking behavior. We also plan to collect additional data for planned analyses of cost-effectiveness, and smoking cessation. Lung-cancer got by biopsy and other biospecimens are available to researchers through a peer-review process All screening examinations are planed to perform in accordance with a standard protocol, developed by medical physicists associated with the trial, that specified acceptable characteristics of the machine and acquisition variables. All low-dose CT scans are acquired with the use of multidetector scanners with a minimum of 16 channels.