The purpose of the study is to systematically characterize nocturnal breathing, oxygenation, and sleep in a sample with non-small cell lung cancer (NSCLC). For lung cancer patients, many factors may affect central respiratory control, upper airway and lung mechanics, and gas exchange - key anatomic and physiologic mechanisms that regulate breathing and oxygenation. These factors include tumor characteristics and their systemic sequelae, iatrogenic effects of treatments, and the effects of common co-morbid conditions such as chronic obstructive pulmonary disease (COPD) or heart failure. When superimposed on normal sleep state dependent alterations in control of breathing and oxygenation, these factors place patients with NSCLC at risk for sleep disordered breathing (SDB) and nocturnal hypoxia. While SDB and nocturnal hypoxia have been identified as important etiologic factors for sleep disturbances in other populations, their role in the prevalent and distressing sleep disturbances experienced by this population has not been examined. This bidirectional effect of sleep and disease processes may have important consequences for several patient outcomes. SDB and nocturnal hypoxia cause poor quality, fragmented sleep which results in daytime sleepiness, fatigue, cognitive impairments, and neurobehavioral dysfunction. Hypoxia stimulates a number of cellular responses that promote tumor growth including expression of the angiogenic polypeptide, vascular endothelial growth factor (VEGF). Intermittent hypoxia, commonly associated with SDB, has been associated with increased levels of serum VEGF, an identified marker of poor survival in NSCLC. However, SDB and nocturnal hypoxia have never been examined in lung cancer patients. Therefore, the aims for this exploratory project are (1) to describe nocturnal breathing, oxygenation, and sleep and (2) to identify their clinical correlates and outcomes in a group of persons with NSCLC. To accomplish the study aims, we will enroll 50 subjects with non-operable NSCLC. [unreadable] Subjects will undergo home pulse oximetry monitoring followed by an overnight admission to the General Clinical Research Center (GCRC) for pulmonary function testing, arterial blood gases, polysomnography (PSG), and early morning serum VEGF. Other correlates such as comorbid conditions, tumor characteristics, and treatment profile will be obtained from the medical record. Subjects will also complete subjective measures of sleep quality, daytime sleepiness, fatigue, pain, and depressive symptoms. Results from this study will advance biomedical knowledge of sleep disorders and the bidirectional interaction of sleep and disease processes in patients with lung cancer. In addition, study data will provide the information necessary to support an RO1 application designed to develop and test population-specific interventions to address these problems. [unreadable] [unreadable] [unreadable]