Yu et al examined the temporal and spatial relationship between pulmonary scarring and lung cancer risk, using longitudinal data from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. In the screening arm of the trial, more than 66 000 participants (aged 55-74 years) received a baseline chest radiographic examination and were followed for up to 12 years for the subsequent development of lung cancer. Lung cancer risk was reported elevated in those individuals with pulmonary scarring detected at baseline. Moreover, the increased risk for cancer was observed in lungs where scarring was present but not in the contralateral lungs, and the risk persisted over the entire duration of follow-up. These findings suggest that inflammation associated with pulmonary scarring may cause localized damage in the lung epithelium and that over time this process may promote the development of lung cancer.