Lymphocyte/Monocyte Ratio is a Novel Predictor for Early Stage Extranodal Natural Killer/T-cell Lymphoma, Nasal Type

Objective: Great heterogeneity exists in clinical behavior and survival outcome in patients with stage IE/IIE extranodal natural killer/T-cell lymphoma, nasal type (ENKTL). In this study, we proposed lymphocyte/monocyte ratio (LMR) as a new prognostic factor for these early stage ENKTL. Methods: We retrospectively examined the LMR as a prognostic variable in a cohort of 379 patients with newly diagnosed stage IE/IIE ENKTL. The relationship between the LMR and clinicopathologic variables were analyzed in Kaplan-Meier log-rank survival analysis, and the Cox proportional hazards model was used to determine the survival significance of the LMR for both progression-free survival (PFS) and overall survival (OS). Results: Patients were categorized into two different groups based on the LMR using cut-off value of 2.0. The 5-year PFS rates in the low and high LMR group were 43.9% and 62.7%, respectively, and the 5-year OS rates in the two groups were 59.1% and 77.7%, respectively. In multivariate analysis, low LMR at diagnosis was associated with worse PFS (hazard ratio 1.611, 95% confidence interval: 1.027-2.525, P =0.038) independent of age (P=0.033) and treatment stratagem (P<0.001), and indicated worse OS (hazard ratio 2.003, 95% confidence interval: 1.124-3.569, P =0.018) independent of age (P=0.007), LDH level (P=0.042), local tumor invasiveness (P=0.008), and treatment stratagem (P<0.001). Conclusion: The LMR is an independent prognostic factor for both DFS and OS in patients with stage IE/IIE ENKTL, and provides additional prognostic value beyond standard clinicopathological parameters.