Impact of COPD on Lung Cancer Screening Positivity in a Specialist-Managed Cohort From Brazil.

BACKGROUND: Individuals with COPD are frequently included in low-dose CT (LDCT) lung cancer screening programs because eligibility criteria are typically based on smoking exposure and age. However, the impact of COPD on LDCT scan results remains incompletely understood and has been little studied among patients under follow-up for chronic respiratory diseases and in middle-income countries. RESEARCH QUESTION: What is the association between COPD-using different definitions-and positive LDCT screening results in a cohort of patients with chronic, stable respiratory diseases in Brazil? STUDY DESIGN AND METHODS: This cross-sectional analysis included patients who underwent lung cancer screening at a tertiary hospital and met US Preventive Services Task Force eligibility criteria. Clinical, pulmonary function, and imaging data were retrospectively collected. COPD was defined as follows: (1) physician-diagnosed COPD, (2) airflow obstruction (FEV1/FVC < 0.70), (3) both criteria combined, and (4) CT scan-detected emphysema. Positive screening was defined as Lung Imaging Reporting and Data System (Lung-RADS) category 3 or 4. Regression analyses adjusted for demographic factors, smoking history, and postinflammatory residual lung opacities. RESULTS: Of the 1,337 screened patients, 1,034 (77%) met US Preventive Services Task Force eligibility criteria and had available data for analysis (mean age, 63.6 years; 53.2% female; mean FEV1, 64% predicted). COPD prevalence by physician diagnosis, airflow obstruction, and both criteria was 73.3%, 54.4%, and 51%, respectively; emphysema was present in 76.5%. Positive screening and Lung-RADS category 4 rates were 12.6% and 5.6%, with lung cancer detected in 2.2%. Emphysema was independently associated with positive screening (prevalence ratio, 1.74; 95% CI, 1.08-2.78; P = .02) and Lung-RADS category 4 (prevalence ratio, 3.27; 95% CI, 1.30-8.20; P = .01). Other COPD definitions were not significantly associated with screening positivity. INTERPRETATION: These findings suggest that emphysema may be the COPD-related feature most strongly linked to screening positivity in this high-respiratory morbidity setting.