PD-L1 Expression is not a Predictive Factor for Recurrence in Resected Non-small Cell Lung Cancer.

Abstract

Although targeting programmed death-1 (PD-1) and its ligand, programmed death-ligand 1 (PD-L1), is an established treatment modality for non-small cell lung cancer (NSCLC), the prognostic relevance of PD-L1 expression in NSCLC patients who undergo pulmonary resection is controversial. Two hundred thirty-seven NSCLC patients who underwent pulmonary resection were enrolled and the relationship between PD-L1 and various clinicopathological factors, as well as the prognostic relevance of PD-L1, was evaluated. PD-L1 expression was significantly higher in male patients (p < 0.01), lymphatic invasion (p < 0.01), vascular invasion (p < 0.01), grade 3-4 differentiation (p < 0.01), squamous cell carcinoma (p < 0.01), and pathological stage > II (p < 0.01), but significantly lower in those who were epithelial growth factor receptor (EGFR) mutation negative (p < 0.01). Relapse-free survival was significantly worse in patients with PD-L1 expression (p = 0.04). Univariate analysis showed that male sex (p = 0.04), carcinoembryonic antigen expression (CEA) (p < 0.01), maximum standardized uptake value (p < 0.01), lymphatic invasion (p < 0.01), vascular invasion (p < 0.01), grade 3-4 differentiation (p < 0.01), lower lobe disease (p = 0.04), PD-L1 expression (p = 0.03), and pathological stage (p < 0.01) were significant risk factors of recurrence. In multivariate analysis, CEA expression (p = 0.01), lymphatic invasion (p = 0.04), and pathological stage (p < 0.01) were risk factors for recurrence, whereas PD-L1 expression was not a significant factor of recurrence (p = 0.62). PD-L1 expression was not a risk factor of recurrence but tumor progression tended to increase PD-L1 expression. The Institutional Review Board of Kanazawa Medical University approved the protocol of this retrospective study (approval number: I392), and written informed consent was obtained from all patients.