Associations of gut microbiota and Chronic Obstructive Pulmonary Disease Assessment Test (CAT) score in chemotherapy treated lung cancer patients with COPD

Introduction: Patients with lung cancer have a high prevalence of chronic obstructive pulmonary disease (COPD). There is a lack in our understanding of pathogenesis and mechanisms accounting for large variability in COPD phenotype. Airway dysbiosis have been implicated with disease severity and exacerbations in COPD. However, the role of gastrointestinal (GI) microbiome in pathogenesis of COPD has not been explored. Recent data suggest that the gut-lung axis regulates systemic immune function. Here, we aimed to evaluate the associations of GI microbiota and CAT score in lung cancer patients with COPD. Methods: We included stool samples from 98 lung cancer patients (adenocarcinoma (n=48), squamous cell (n=24), small cell lung cancer (n=15) and other (n=11). Of these, 59 had COPD and 39 did not have COPD. We analyzed the gut microbiome according to CAT score, FEV1, and chemotherapy (CHT) response using shotgun metagenomic sequencing technique. We performed Spearman correlation between gut microbial species and continuous variables. Results: Lachnospiraceae bacterium has a positive correlation (r=0.45) with CAT score. Non-responders had significantly higher CAT score (vs. responders, median CAT score of 23 vs 13, respectively (p<0.05). Correlation analysis for gut microbiome and CHT response and how FEV1 relates to the continuous variables will be presented at the conference. Conclusion: There were associations with certain gut bacteria species and CAT score. Higher CAT score associates with non-response to CHT administered to lung cancer patients.