Lung Cancer Biomarkers and Screening

OBJECTIVES: * Identify and validate biomarkers for the early detection of lung cancer in individuals at low- or high-risk for smoking-related cancers. * Identify preneoplastic cellular changes and lesions in these patients. OUTLINE: Participants are stratified according to lung cancer risk status (with or without increased risk). Group 1 (screening cohort): Participants complete a questionnaire and undergo pulmonary function testing, multidetector chest CT scan, sputum induction, and phlebotomy. Group 2 (rule-out lung cancer): Participants complete the same questionnaire and undergo the same tests and scans as in group 1. Some participants may undergo fiberoptic bronchoscopy based upon CT scan results with transbronchial or endobronchial biopsies. Some participants may undergo lung resection. Tissue samples are collected from surgery or biopsy. PROJECTED ACCRUAL: A total of participants will be accrued for this study.