Impact of Airway Mucus Plugs on Secondary Pulmonary Fibrosis in COPD Patients: A Single-Center Case-Control Study

Inclusion criteria

• ① Age ≥ 18 years old;

• Planned radical resection for lung cancer, with postoperative pathological diagnosis of primary lung cancer;

• During surgery, non tumor lung tissue at a distance of ≥ 5 cm from the tumor edge can be obtained; ④ Case group: Preoperative pulmonary function examination confirmed diagnosis of COPD (FEV ₁/FVC<0.70); ⑤ Control group: Preoperative lung function was normal (FEV ₁/FVC ≥ 0.70), with no history of COPD; ⑥ The subjects are able to understand and sign the informed consent form

Exclusion criteria

• ① Clear presence of other interstitial lung diseases (ILD) or idiopathic pulmonary fibrosis before or during surgery （IPF）、 Fibrosis after pneumoconiosis or tuberculosis;

• Active pulmonary infections (such as bacterial pneumonia, fungal infections, active tuberculosis);

• Having received neoadjuvant radiotherapy or chemotherapy, which may affect the morphology or molecular results of distal lung tissue; ④ Combined severe immunodeficiency or long-term systemic immunosuppressive therapy (such as glucocorticoids ≥ 20 mg/d, More than 4 weeks);

• Merge with other serious systemic diseases (such as advanced heart failure, end-stage renal disease), affecting study compliance or Survival expectation; ⑥ Pregnant or lactating women; ⑦ Refusing to sign the informed consent form or deemed unsuitable by the researcher to participate in the study.