Oral Iloprost for the Prevention of Lung Cancer In Former Smokers

Inclusion Criteria: * Participants must be former smokers (\> 12 months abstinent and confirmed by serum cotinine) with at least a 30 pack-year cigarette history who are at high risk for the development of lung cancer with at least one of the following: * Stage I or II lung cancer survivors, surgically treated with curative intent, who have remained disease free for \> 12 months. Participants may have been treated with adjuvant chemotherapy or targeted therapy \[(e.g. Osimertinib for epidermal growth factor receptor (EGFR) mutation)\], if appropriate, provided they are \> 12 months from the last systemic adjuvant therapy dose. * Patients with chronic obstructive pulmonary disease (COPD), defined as either airflow obstruction (forced expiratory volume in 1 second \[FEV1\]/forced vital capacity \[FVC\] \< 0.70) on spirometry or emphysema (as commented on in a Radiology report) on CT scan. * Patients who display a ground glass opacity (GGO) on CT with a largest diameter =\< 10 mm and \>= 4 mm on axial imaging. The GGO must either be documented to have remained the same size or slowly progressing, but not regressing, over a 6-month period of observation by serial CT scan such that further workup beyond observation is not planned. A solid component of =\< 1/3 of the axial diameter may be present, providing the treating physician(s) do not plan on workup for resection within the next 6 months, taking both the character of the lesion and its rate of growth into consideration…