Background
Bronchiectasis are a frequent incidental finding on chest Computed Tomography (CT), but their relevance in lung cancer screening are not fully understood.
Objective
To investigate the association between bronchiectasis and respiratory symptoms, pulmonary function, CT-quantified emphysema and airway wall thickness in lung cancer screening participants with and without chronic obstructive pulmonary disease (COPD).
Methods
We included (ex-)smokers from the Nelson trial with COPD (n=1121) defined according to GOLD criteria and without COPD (n=2139). Bronchiectasis were scored by chest radiologists. The relationship with pulmonary function (FEV1%predicted, FEV1/FVC), respiratory complaints (cough, dyspnea, wheezing, mucus hypersecretion), CT quantified emphysema (15th percentile) and airway wall thickness (Pi10) were examined with independent t-tests and multivariate regression.
Results
Bronchiectasis was present in 5.4% (n=175/3,260), with no difference between subjects with and without COPD (5.9% vs. 5.1%, p=.368). In COPD subjects with bronchiectasis compared to those without, subjects with bronchiectasis had a lower FEV1%predicted (76.2% vs. 85.0%; p<.001), lower FEV1/FVC (57.8 vs. 62.0; p<.001), more emphysema (-938.6HU vs. -930.0HU, p=.001). In these subjects, bronchiectasis was independently associated with a lower FEV1%predicted (B=-7.7 [-12.3, -3.3]), lower FEV1/FVC (B=-2.5 [-4.3, -0.8]), more cough (OR 2.4 [1.3, 4.3]) and more dyspnea (OR 2.3 [1.3, 3.9]).
Conclusion
Bronchiectasis are associated with respiratory symptoms, lower lung function and more emphysema in lung cancer screening participants with COPD.