Pretreatment combination of platelet counts and neutrophil–lymphocyte ratio predicts survival of nasopharyngeal cancer patients receiving intensity-modulated radiotherapy
Authors Lin YH, Chang KP, Lin YS, Chang TS
Received 14 March 2017
Accepted for publication 6 May 2017
Published 26 May 2017 Volume 2017:10 Pages 2751—2760
Checked for plagiarism Yes
Review by Single-blind
Peer reviewers approved by Dr Akshita Wason
Peer reviewer comments 2
Editor who approved publication: Dr Tohru Yamada
Yu-Hsuan Lin,1 Kuo-Ping Chang,2 Yaoh-Shiang Lin,2,3 Ting-Shou Chang2–4
1Department of Otolaryngology, Head and Neck Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, 2Department of Otolaryngology, Head and Neck Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, 3Department of Otolaryngology, Head and Neck Surgery, National Defense Medical Center, Taipei, 4Institute of Public Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan, Republic of China
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.
Keywords: nasopharyngeal carcinoma, intensity-modulated radiotherapy, inflammation-based marker, combination of platelet count and neutrophil–lymphocyte ratio, prognosis