Neutrophil‐to‐Lymphocyte Ratio as a Predictor for PD‐L1 Inhibitor Treatment in Recurrent or Metastatic Nasopharyngeal Carcinoma

Neutrophil-to-lymphocyte ratio (NLR) can be treated as a simple indicator of patients' immune status by representing the state of the systemic inflammatory response. Immunotherapy now is the accepted second-line treatment for recurrent or metastatic nasopharyngeal carcinoma (R/M NPC). However, the significance of NLR in patients with R/M NPC undergoing treatment with PD-L1 (programmed cell death-ligand 1) inhibitors is still uncertain. We analyzed the relationship between baseline NLR with 153 patients' efficacy and survival from a multicenter, prospective, Phase 2 study. We employed restricted cubic spline plots to get the nonlinear relationship between NLR and progression-free survival (PFS) or overall survival (OS). We identified the ideal cut-off value through the analysis of the receiver operating characteristic curve (ROC curve). We used Logistic regression, Cox regression, Log-rank test, and Kaplan-Meier method to analyze the association between NLR and patients' disease control rate (DCR) and PFS or OS. The ideal threshold value for NLR was 2.826. NLR was identified as a significant independent predictor of DCR (OR = 0.17, 95% CI = 0.05-0.48, p = 0.001), indicating that a higher NLR is associated with worse DCR. NLR (AUC = 0.634) showed superior predictive capability for DCR in comparison to lymphocytes (AUC = 0.602) and neutrophils (AUC = 0.593). High NLR values were risk factors both for poor PFS (HR = 2.53, 95% CI = 1.58-4.06, p < 0.001) and OS (HR = 3.89, 95% CI = 2.09-7.24, p < 0.001). Elevated NLR is strongly associated with lower response to treatment and reduced survival rates in patients with R/M NPC being treated with PD-L1 inhibitors. Patients with high NLR values have poor efficacy and survival.