Chronic Obstructive Pulmonary Disease and Inhaled Treatment Effects on Mortality in Patients with Lung Cancer

Rationale: In patients with lung cancer, the impact of chronic obstructive pulmonary disease (COPD) diagnosis and subsequent management on mortality remains uncertain, because evidence supporting the efficacy of inhaled therapies in improving clinical outcomes in this population is limited. Objectives: This aim of this study was to assess whether COPD worsens outcomes in patients with lung cancer and to investigate whether inhaled treatments for COPD can improve these outcomes. Methods: This retrospective cohort study used the Korea Central Cancer Registry database from 2012 to 2019. Patients with lung cancer aged 40 years and older with health screening records were included. Patients were classified into COPD and non-COPD groups, and within the COPD group, they were further classified on the basis of inhaled therapy status. The primary outcome was all-cause mortality, and secondary outcomes included healthcare resource use. Subgroup analyses were conducted on the basis of lung cancer stage, histologic subtypes, and treatment modalities. Results: Among 113,071 patients with lung cancer, 38,145 (33.7%) had COPD. COPD was associated with higher all-cause mortality (adjusted hazard ratio, 1.327; 95% confidence interval, 1.305-1.350; P < 0.001), increased use of steroids and antibiotics, higher rates of hospital admissions, and more frequent emergency department visits. Patients with COPD receiving inhaled treatment had lower mortality rates at the 3-month landmark (adjusted hazard ratio, 0.934; 95% confidence interval, 0.895-0.975; P = 0.002). Notably, the dual bronchodilator combination (long-acting β-agonist/long-acting muscarinic antagonist) was associated with a significant mortality reduction, as observed across multiple landmark time points. Conclusions: COPD is linked to worse clinical outcomes in patients with lung cancer. Among the inhaled treatments, the long-acting β-agonist/long-acting muscarinic antagonist dual therapy showed a beneficial effect on mortality, whereas adding inhaled corticosteroids as part of triple therapy did not provide an additional survival benefit. This study suggests the importance of early COPD detection and timely initiation of inhaled therapy in patients with lung cancer.