Before treatment begins, participants will have a bronchoscopy (tissue sample from the lung). This is taken to see if different elements (biomarkers) in the tissue can predict which individuals are at higher risk for developing cancer. In a bronchoscopy a tube will be placed through the nose into the lung (while under sedation) to remove tissue samples for laboratory analysis (biopsy). Cells will also be collected during the bronchoscopy by spraying the lungs with a small amount water and then removing the water (bronchial lavage, bronchial washing). In addition, a sputum sample will be taken and the inside of the cheek will be scraped (buccal sample).