Pretreatment combination of platelet counts and neutrophil–lymphocyte ratio predicts survival of nasopharyngeal cancer patients receiving intensity-modulated radiotherapy

BACKGROUND Increased cancer-related inflammation has been associated with unfavorable clinical outcomes. The combination of platelet count and neutrophil-lymphocyte ratio (COP-NLR) has related outcomes in several cancers, except for nasopharyngeal carcinoma (NPC). This study evaluated the prognostic value of COP-NLR in predicting outcome in NPC patients treated with intensity-modulated radiotherapy (IMRT). MATERIALS AND METHODS We analyzed the data collected from 232 NPC patients. Pretreatment total platelet counts, neutrophil-lymphocyte ratio (NLR), and COP-NLR score were evaluated as potential predictors. Optimal cutoff values for NLR and platelets were determined using receiver operating curve. Patients with both elevated NLR (>3) and platelet counts (>300×109/L) were assigned a COP-NLR score of 2; those with one elevated or no elevated value were assigned a COP-NLR a score of 1 or 0. Cox proportional hazards model was used to test the association of these factors and relevant 3-year survivals. RESULTS Patients (COP-NLR scores 1 and 2=85; score 0=147) were followed up for 55.19 months. Univariate analysis showed no association between pretreatment NLR >2.23 and platelet counts >290.5×109/L and worse outcomes. Multivariate analysis revealed that those with COP-NLR scores of 0 had better 3-year disease-specific survival (P=0.02), overall survival (P=0.024), locoregional relapse-free survival (P=0.004), and distant metastasis-free survival (P=0.046). Further subgrouping by tumor stage also revealed COP-NLR to be an unfavorable prognostic indicator of 3-year failure-free survival (P=0.001) for locally advanced NPC. CONCLUSION COP-NLR score, but not NLR alone or total platelet count alone, predicted survival in NPC patients treated with IMRT-based therapy, especially those with stage III/IVA, B malignancies.