Chest Computed Tomography (CT) Screening Study With Antibody Testing

* Persons 50-75 * Asymptomatic for lung cancer * Current or former (stopped smoking less than 10 years ago) cigarette smokers * History of cigarette smoking of at least 20 pack years * History of cigarette smoking with a family history of lung cancer which gives an individual a personal risk similar to a smoking history of 20 pk/years (i.e. 1% at 5 years). * Mentally competent individuals to sign an informed consent. * Healthy enough to undergo pulmonary resection or stereotactic body radiotherapy. * A fully informed signed consent form must have been obtained.