This prospective observational study aims to evaluate whether immune profiles of T-cell subsets in bronchoalveolar lavage fluid can complement tumor PD-L1 expression, assessed by immunohistochemistry in tumor tissue specimens, in predicting clinical outcomes in patients with advanced lung cancer. Although tumor PD-L1 expression measured on tissue biopsies is widely used to guide immunotherapy decisions, its predictive value is limited by spatial heterogeneity and sampling variability. By analyzing activated, exhausted, and regulatory T-cell populations in bronchoalveolar lavage fluid and examining their association with tissue-based tumor PD-L1 expression, this study seeks to determine whether combining local immune biomarkers with PD-L1 expression improves the prediction of treatment response and survival in patients receiving standard-of-care systemic therapy.
Adults aged 19 years or older
Patients with suspected or histologically confirmed stage IV lung cancer based on clinical and radiologic findings
Scheduled to undergo clinically indicated bronchoscopy with bronchoalveolar lavage as part of routine clinical care
Able and willing to provide written informed consent
Receipt of treatment for acute lower respiratory tract infection (including pneumonia or fungal infection) within 4 weeks prior to bronchoscopy
History of solid organ transplantation or hematopoietic stem cell transplantation
Current use of systemic immunosuppressive therapy
Current or planned use of biologic immunomodulatory agents
Seoul National University Hospital
Lead sponsor
SMG-SNU Boramae Medical Center
Collaborator