Clinicopathological and Molecular Characteristics Promoting PD-L1 Expression in Early-stage Lung Adenocarcinoma and Squamous Cell Carcinoma

Background/Aim: Lung adenocarcinoma and lung squamous cell carcinoma represent the most prevalent subtypes of non-small cell lung cancer eligible for surgery in the early stages. The emergence of immune checkpoint inhibitors as adjuvant therapy has shown promising potential in improving the postoperative prognosis of patients with lung cancer. Hence, a comprehensive understanding of the clinicopathological and molecular features of programmed cell death ligand-1 (PD-L1) expression in lung adenocarcinoma and squamous cell carcinoma is crucial. Patients and Methods: In this retrospective study, we conducted a comparative analysis of clinicopathological features associated with the expression of PD-L1, stratifying patients who underwent surgical resection into two distinct groups: 289 patients with lung adenocarcinoma and 66 with lung squamous cell carcinoma. Furthermore, we investigated the associations between the expression of PD-L1 and genetic alterations in well-established oncogenic driver mutations. Results: Among the cases, 52.9% exhibited negative PD-L1 expression, 32.9% had low PD-L1 expression, and 12.3% had high PD-L1 expression in adenocarcinoma, while the PD-L1 expression in squamous cell carcinoma showed a near-even distribution.