The Airway Microbiota of Non-small-cell Lung Cancer Patients and its Relationship to Tumor Stage and EGFR Gene Mutation

Background: Accumulating studies have suggested the airway microbiota of lung cancer was significantly different from healthy controls. However, little was known about the relationship between airway microbiota and important clinical parameters of lung cancer. In this study, we aimed to explore the association between sputum microbiota and lung cancer stage, lymph node metastasis, intrathoracic metastasis, and Epidermal growth factor receptor (EGFR) gene mutation. Methods: The microbiota of sputum samples from 85 newly diagnosed NSCLC patients were sequenced via 16S rRNA sequencing with V3-V4 region. Sequencing reads were filtered using QIIME2 and clustered against UPARSE. Results: The α diversity and β diversity was significantly different between patients in stage I to II (early stage, ES) and patients in stage III to IV (advanced stage, AS). Lefse identified that genera Granulicatella and Actinobacillus were significantly enriched in ES, and genus Actinomyces were significantly enriched in AS. PICRUSt2 identified NAD salvage pathway was significantly enriched in AS, which was positively associated with Granulicatella. Patients with intrathoracic metastasis were associated with increased genus Peptostreptococcus and incomplete reductive TCA cycle. Enrichment of TCA cycle was associated with increased Peptostreptococcus. Genera Parvimonas, Pseudomona and L-valine biosynthesis were positively associated with lymph node metastasis. L-valine biosynthesis was related with increased Pseudomona. Finally, genus Parvimonas were significantly upregulated in adenocarcinoma patients with EGFR mutation. Conclusion: In conclusion, the taxonomy structure differed between different lung cancer stage. The tumor stage, intrathoracic 1 metastasis, lymph node metastasis, and EGFR mutation were associated with alteration of specific airway genera and metabolic function of sputum microbiota.