Immune Checkpoint Inhibitor for Non-small Cell Lung Cancer With Negative or Low Tumor PD-L1 Expression.

Background/aim: We conducted a retrospective analysis of the survival durations of 25 patients diagnosed as having non-squamous cell non-small cell lung cancer with negative or low tumor programmed death-ligand 1 (PD-L1) expression treated with immune checkpoint inhibitor (ICI) monotherapy.

Patients And Methods: The progression-free (PFS) and overall (OS) survival were calculated from the initiation of ICI monotherapy. The association between the patient characteristics and the PFS was analyzed using Cox proportional hazards model.

Results: The median PFS was 2.6 months, and the 12-month PFS rate was 9.3%. The median OS was 5.5 months, and the 12-month OS rate was 39.8%. A Cox proportional hazards model identified the neutrophil/lymphocyte ratio and presence of liver metastasis as being significantly associated with PFS.

Conclusion: Our findings suggest that a subset of patients with non-squamous cell non-small cell lung cancer who show negative or low tumor PD-L1 expression could benefit from ICI monotherapy.