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

OBJECTIVES: Primary * Compare the reversal of premalignant histological changes in the bronchial epithelium of patients at high risk for lung cancer (defined by \> 20 pack years of smoking and sputum atypia) treated with iloprost vs placebo. * Determine whether this drug modulates Ki-67 proliferation index (Antigen Ki-67) in these patients. * Determine whether this drug affects prostaglandin metabolism in these patients. * Determine the toxicity profile of this drug in these patients. Secondary * Determine whether this drug modulates a panel of biomarkers, including MCM-2(Minichromosome maintenance protein: forms DNA helicase), EGFR (Epidermal growth factor receptor: cell surface receptor for the epidermal growth factor family of proteins. Mutations in EGFR expression or activity can result in cancer.) , HER2/neu (Human epidermal growth factor receptor 2 HER2 is a member of the EGFR family), RARβ (Retinoic Acic Receptor Beta is a nuclear transcription regulator and a member of the thyroid-steroid hormone receptor superfamily), p53, FHIT (Fragile histidine triad protein is an enzyme involved in purine metabolism and had been demonstrated to be a tumor suppressor), apoptotic index, and microvessel density, in these patients. * Determine the genes whose expression is altered by this drug in these patients. OUTLINE: This is a randomized, double-blind, placebo-controlled, multicenter study. Patients are stratified according to smoking status (current vs former) and participating center. Patients are randomized to 1 of 2 treatment arms. * Arm I: Patients receive oral iloprost twice daily. * Arm II: Patients receive oral placebo twice daily. In both arms, treatment continues for 6 months in the absence of unacceptable toxicity. Patients are followed at 1 month and then annually thereafter. PROJECTED ACCRUAL: A total of 152 patients (76 \[38 current smokers and 38 former smokers\] per treatment arm) will be accrued for this study within 2 years.