Chronic obstructive pulmonary disease and lung cancer incidence in never smokers: a cohort study
This large national cohort study (338,548) found COPD was a strong independent risk factor for lung cancer incidence in never smokers (adjusted HR of 2.67; 95% 2.09-3.40 for never smokers with COPD compared to never smokers without COPD).
Source:
Thorax