Abstract
PURPOSE: Various blood cell parameters have been identified as predictive markers of tumor responses and the survival of patients with cancer treated with immune checkpoint inhibitors. The purpose of this study is to assess the ability of various blood cell parameters to predict therapeutic effects and survival in patients with esophageal squamous cell carcinoma (ESCC) treated with nivolumab monotherapy. PATIENTS AND METHODS: We evaluated neutrophil-to-lymphocyte (NLR), platelet-to-lymphocyte (PLR) and lymphocyte-to-monocyte (LMR) ratios as predictive markers of patients' survival and effects of nivolumab monotherapy after one or more prior chemotherapies for unresectable advanced or recurrent ESCC. RESULTS: The objective response and disease control rates were 20.3% and 47.5%, respectively. The LMRs before, and 14 and 28 days after nivolumab initiation were significantly higher in patients with complete response (CR)/partial response (PR)/stable disease (SD) than those with progressive disease (PD). The NLRs at 14 and 28 days after nivolumab initiation were significantly lower in patients with CR/PR/SD than with PD. The optimal cutoffs for these parameters significantly discriminated patients with CR/PR/SD and PD. Univariate and multivariate analyses identified pretreatment NLRs as a significant independent factor for progression-free and overall survival (hazard ratio [HR]: 1.19, 95% confidence interval [CI]: 1.07-1.32, and HR 1.23, 95% CI: 1.11-1.37, respectively; p ≤ 0.001 for both). CONCLUSION: The pretreatment LMRs, and NLR and LMR at 14 and 28 days after starting nivolumab monotherapy were significantly associated with the clinical therapeutic effect. The pretreatment NLR was significantly associated with patients' survival. These blood cell parameters before and during the early days of nivolumab monotherapy can help to identify patients with ESCC who would most likely benefit from nivolumab monotherapy.