Microbiota in Neoadjuvant Chemoimmunotherapy for NSCLC

Inclusion Criteria:

1. Age between 18 and 80 years;
2. Newly diagnosed, driver gene-negative non-small cell lung cancer (NSCLC) confirmed by histopathology (Stage IIA-IIIB);
3. At least one measurable lesion as defined by RECIST version 1.1; Eastern Cooperative Oncology Group (ECOG) performance status of 0-1;
4. No prior systemic therapy or radiotherapy;
5. Eligible for surgical resection and suitable for neoadjuvant immunotherapy or chemotherapy as determined by multidisciplinary evaluation;
6. Signed written informed consent prior to study participation;
7. Adequate pulmonary ventilation and diffusion function confirmed by pre-enrollment pulmonary function test to allow for surgical resection.

Exclusion Criteria:

1. Requirement for systemic glucocorticoid therapy or other immunosuppressive treatments;
2. Use of antibiotics or presence of infections requiring antibiotic therapy within the past 3 months;
3. Probiotic use within 3 months prior to enrollment;
4. Presence of obstructive pneumonia, cancerous cavitation, or active pulmonary tuberculosis;
5. Presence of bronchiectasis, concurrent pulmonary infections, pulmonary fibrosis, or uncontrolled diabetes mellitus;
6. Presence of a primary tumor in another organ;
7. Receipt of chemotherapy or any other cancer treatment prior to enrollment;
8. Confirmed brain metastases by contrast-enhanced MRI before enrollment;
9. Active or pre-existing autoimmune diseases;
10. Uncontrolled comorbidities including heart failure, uncontrolled hypertension, unstable angina, or interstitial lung disease;
11. Positive for hepatitis B surface antigen or detectable hepatitis C RNA requiring treatment;
12. Known history or positive test for human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS);
13. Pregnant or breastfeeding women;
14. Previous treatment with anti-PD-1, anti-PD-L1, anti-PD-L2, or anti-CTLA-4 antibodies.