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

Background

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.

Methods

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.

Results

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).

Conclusion

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.