Immunotherapy with programmed death cell ligand-1 (PD-L1) antibodies is an essential treatment for non-small cell lung cancer (NSCLC), and immunohistochemical assessment of PD-L1 expression is required for therapeutic stratification.

This study analyzed PD-L1 expression in paired small biopsy and surgical specimens from patients with NSCLC, including adenocarcinoma and squamous cell carcinoma. Associations with the histological type, pathological stage, and clinicopathological parameters were evaluated, and concordance between biopsies and corresponding resections was assessed. A five-year retrospective-prospective study included 102 patients. Programmed death cell ligand-1 expression was determined by immunohistochemistry using monoclonal antibody clone 28-8.

Membranous staining in more than 1% of tumor cells was considered positive. No statistically significant difference in PD-L1 expression was found between small biopsy and surgical specimens (p = 0.790). Expression showed no significant association with patient age or gender. A significant association was observed between PD-L1 expression and smoking status in both specimen types (p = 0.012 and p = 0.019). Programmed death cell ligand-1 expression was not significantly related to the T descriptor (p = 0.548) or N descriptor (p = 0.617).

A statistically significant correlation was identified between PD-L1 positivity and disease stage (p = 0.012). The high concordance of PD-L1 expression between biopsy and surgical material supports use of biopsies for immunotherapy planning in ineligible patients and confirms reliability of resection specimens for adjuvant treatment decisions.