Abstract
PURPOSE: This study evaluated the impact of neutrophil-to-lymphocyte ratio on the survival of patients with esophageal squamous cell carcinoma (ESCC) who underwent proton beam therapy with concurrent chemotherapy. MATERIALS AND METHODS: Data of patients with ESCC who received definitive proton beam therapy with concurrent chemotherapy between January 2015 and January 2020 were retrospectively analysed. The 3-year overall and progression-free survival rates were calculated. Prognostic factors, including neutrophil-to-lymphocyte ratio, were examined. RESULTS: In total, 116 consecutive patients with ESCC (median age, 68 years; range, 45 to 90 years) were included. The median follow-up time was 51.2 months (range, 3.0 to 114.0). Complete clinical response was observed in 75 patients (64.7%). The 3-year overall and progression-free survival rates were 82.4% and 59.4%, respectively. In a multivariate analysis, a Eastern Cooperative Oncology Group performance status ≥1 (hazard ratio [HR], 2.52; 95% confidence interval [CI], 1.00 to 6.34; p = 0.049), clinical stage Ⅳ disease according to the Union for International Cancer Control 8th edition (HR, 3.37; 95% CI, 1.30 to 8.77; p = 0.013), and a neutrophil-to-lymphocyte ratio ≥3.00 (HR, 3.89; 95% CI, 1.36 to 11.19; p = 0.012) were significantly associated with poorer overall survival. Clinical stage Ⅳ disease (HR, 2.86; 95% CI, 1.50 to 5.44; p = 0.003) and neutrophil-to-lymphocyte ratio ≥3.00 (HR, 2.40; 95% CI, 1.32 to 4.39; p = 0.004) were significantly associated with poorer progression-free survival. CONCLUSION: In patients with ESCC who received definitive proton beam therapy with concurrent chemotherapy, a high neutrophil-to-lymphocyte ratio was a significant poor prognostic factor for both overall and progression-free survival.