Iloprost in Preventing Lung Cancer in Patients at High Risk for This Disease

Inclusion Criteria: * Current or former smoker with ≥ 20 pack-year history of smoking with no tobacco use within the past 6 months * Mild atypia or worse on sputum cytology, or * Bronchial biopsy with mild or worse dysplasia within the past 12 months * Age 18 and over * SWOG (Southwest Oncology Group)0-2 * Life expectancy at least 6 months * Granulocyte count \> 1,500/mm\^3 * Platelet count \> 100,000/mm\^3 * Alkaline phosphatase ≤ 2.5 times upper limit of normal (ULN) * Transaminases ≤ 2.5 times ULN * Bilirubin ≤ 2.0 mg/dL * Albumin ≥ 2.5 g/dL * Creatinine ≤ 1.5 mg/dL * Well-controlled atrial fibrillation OR rare (\< 2 minutes) premature ventricular contractions allowed * Negative pregnancy test * Fertile patients must use effective contraception * Able and willing to undergo bronchoscopy Exclusion Criteria * Clinically apparent bleeding diathesis * Ventricular tachycardia * Multifocal premature ventricular contractions or supraventricular tachycardias with rapid ventricular response * Pneumonia or acute bronchitis within the past 2 weeks * Hypoxemia (\< 90% saturation with supplemental oxygen) * Pregnant or nursing * Malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer or carcinoma in situ of the cervix * Serious medical condition that would preclude bronchoscopy or study participation * Clinically active coronary artery disease * Myocardial infarction within the past 6 weeks * Chest pain * Congestive heart failure * Cardiac dysrhythmia that is potentially life-threatening Exclusion for PRIOR CONCURRENT THERAPY: * Biologic therapy (Not specified) * More than 5 years since prior chemotherapy * More than 6 weeks since prior inhaled steroids * More than 5 years since prior thoracic radiotherapy * Surgery (Not specified) * No prior prostacyclin