Peripheral Blood Markers Associated with Immune-Related Adverse Effects in Patients Who Had Advanced Non-Small Cell Lung Cancer Treated with PD-1 Inhibitors

Background: Immune checkpoint inhibitors (ICIs) have transformed the treatment landscape for patients with advanced non-small-cell lung cancer (aNSCLC), but immune-related adverse events (irAEs) have been evidenced curtailed the clinical use of them.

Purpose: The aim of this study was to research the influences of inflammation-related peripheral blood markers, including neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) levels, on anti-PD-1 inhibitor-induced irAEs.

Patients And Methods: A retrospective analysis was conducted of patients treated with PD-1 inhibitors for stage III-IV NSCLC at a single center from 2017 to 2020 were included. Clinical characteristics, peripheral blood markers at the baseline and before subsequent treatment cycles were collected. NLR and PLR were calculated by division of neutrophil and platelet by lymphocyte measured in peripheral blood. The development of irAEs was evaluated and monitored from the therapy start based on CTCAE V4.03.

Results: A total of 150 patients were included. Fifty-seven patients had occurred at least one irAEs during follow-up, and mainly grade 1-2 (73.68%). Pruritus, rash and thyroiditis were the most commonly irAEs. Low NLR, PLR and neutrophil at baseline were significantly associated with the development of severe irAEs (-values were 0.023, 0.0016 and 0.009). The levels of neutrophil, NLR and PLR also significantly decreased when occurred irAEs compared with baseline (P-values were 0.0069, 0.017 and 1.18E-5, respectively).

Conclusion: The levels of NLR, PLR and neutrophil were associated with the increased risk of severe irAEs when baseline levels were low. NLR, PLR, and neutrophil are simple and available biomarkers that can be used to help predict severe adverse effects in NSCLC patients treated with anti-PD-1 inhibitors.