Clinical Significance of PD-L1 Expression in Brain Metastases from Non-small Cell Lung Cancer

Abstract

Aim: To investigate the association between positivity for programmed cell death-ligand 1 (PD-L1) in brain metastases (BM) and the prognosis or clinical factors in patients with non-small cell lung cancer (NSCLC).

Materials and methods: Thirty-two patients with surgically resected brain-metastatic NSCLC were enrolled. The PD-L1 expression in BM was analyzed using the antibody against human PD-L1 (clone SP142). The PD-L1 positivity was defined as PD-L1 expression on brain-metastatic tumor cells of ≥5%.

Results: Seven (21.9%) out of 32 patients showed PD-L1 positivity in BM. The PD-L1-positive BM group had a significantly shorter brain-specific disease-free survival than the PD-L1-negative BM group (p<0.05). PD-L1 positivity in BM was significantly associated with a heavy smoking history and the administration of radiotherapy for BM before surgery (p<0.05 and p<0.05, respectively).

Conclusion: The PD-L1 expression in BM from NSCLC may be associated with local recurrence following surgery, and the smoking- or radiotherapy-derived effects.

Keywords: Programmed cell death-ligand 1; brain metastasis; non-small cell lung cancer; prognosis.