COPD as a comorbidity in lung cancer

<bold>Background:</bold> Chronic Obstructive Pulmonary Disease (COPD) is as a common comorbidity in individuals diagnosed with lung cancer, amplifying respiratory challenges and complicating treatment strategies. <bold>Aims and objectives:</bold> We aimed to assess the burden of COPD as a comorbidity of lung cancer patients in terms of therapy, risk for pneumonia or pneumonitis, and overall survival. <bold>Methods:</bold> We used claims data of lung cancer patients diagnosed in 2015-2016 from a German statutory health insurance fund. We compared numerical and categorical outcomes between patients with and without COPD using t-test and Chi2-test. We used multivariate Cox regression to assess the impact of COPD on survival, adjusted by age, sex, and comorbidities. <bold>Results:</bold> In our study of 36,272 lung cancer patients, 51.7% had pre-existing COPD. Patients with COPD were older, had a higher comorbidity burden, and were predominantly male. COPD patients presented with different cancer stages, notably fewer in stage IV (53.3% vs. 63.8%, p<0.0001). Surgical resection rates were lower in COPD patients in lower stages (p<0.0001), while radiotherapy rates were higher (p<0.0001). Additionally, COPD patients had a higher incidence of pneumonia (52.5% vs. 44.9%, p<0.0001). Multivariate Cox regression indicated significantly impacted overall survival in COPD patients with lymph node involvement (HR=1.07, p=0.04), stage IV Ma (HR=1.09, p=0.03), and stage IV Mb or Mc (HR=1.04, p=0.02), but not in early stages. <bold>Conclusion:</bold> COPD as a comorbidity has a major impact on treatment and disease trajectories in lung cancer patients. Importantly, COPD has a negative impact on survival of lung cancer patients, although lung cancer is diagnosed earlier in patients with comorbid COPD.