• Diagnosis of extensive and severe dysplasia of the respiratory epithelium
• Patients without dysplasia of the respiratory epithelium recruited from specific screening projects or physicians
• Survived one or more aerodigestive system carcinomas for at least 1 year
• Completely resected stage I non-small cell lung cancer
• Undergoing routine panendoscopy for head and neck cancer, bronchogenic carcinoma resection, bronchoscopy for lung cancer diagnosis or staging, or bronchoscopy for surveillance after high-grade dysplasia
• No asthma
• No lung disease
• No respiratory illness within the past 2 weeks
• No clinically apparent bleeding diathesis or known bleeding disorder
• No angina or clinically active coronary artery disease
• No multifocal premature ventricular contractions
• No poorly controlled congestive heart failure
• No myocardial infarction within the past 6 weeks
• No potentially life-threatening cardiac dysrhythmia
• Well-controlled atrial fibrillation or rare premature ventricular contractions allowed
• No ventricular or supraventricular tachycardia with rapid ventricular response
• No other serious medical condition preventing bronchoscopy
• No acute bronchitis or pneumonia within the past 8 weeks except if related to lung cancer
• No hypoxemia (oxygen saturation below 90% with supplemental oxygen) before bronchoscopy

History of severe allergic reactions to study medication Currently pregnant or breastfeeding Recent participation in another clinical trial within the last 30 days Presence of uncontrolled medical conditions that could affect safety