Objective: New phenotypes of chronic obstructive pulmonary disease (COPD) based on emphysema severity have been recognized recently. The purpose of this study was to determine the relationship between emphysema severity (phenotype) and lung cancer location in patients with COPD.
Materials and methods: Four hundred patients with 405 primary lung cancers confirmed pathologically between January 2010 and March 2014 were included in the study. Of these, 193 patients received a diagnosis of COPD according to the Global Initiative for Chronic Obstructive Lung Disease guidelines. We scored emphysema severity (0-4) on thin-section CT and assigned the anatomic tumor location of lung cancer as peripheral or central.
Results: Patients with COPD had a higher proportion of centrally located lung cancer compared with those without COPD (36.4% vs 17.4%; p < 0.001). In patients with COPD, lower emphysema grades (odds ratio [OR], 0.69; 95% CI, 0.51-0.93; p = 0.016) and reduced ratio of forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) (OR, 0.94; 95% CI, 0.89-0.99; p = 0.024) were associated with central location. After adjusting for age, smoking, and spirometry results, the proportion of central location was approximately four times higher in patients with lower emphysema grades (0-2, < 25%) than in those with severe grades (grade 4, > 51%).
Conclusion: Lower emphysema grades and reduced FEV1/FVC seemed to be independent predictors of central location of lung cancer in COPD. Therefore, in patients with COPD with lower grade emphysema and airway-predominant disease, additional screening tools may have to be considered for central lung cancer detection along with thin-section CT.
Keywords: chronic obstructive pulmonary disease; emphysema; lung cancer.