Elevated peripheral blood lymphocyte-to-monocyte ratio predicts a favorable prognosis in the patients with metastatic nasopharyngeal carcinoma

Introduction: Patients with metastatic nasopharyngeal carcinoma (NPC) have variable survival outcomes. We have previously shown that an elevated peripheral blood lymphocyte-to-monocyte ratio (LMR) is associated with an increased metastatic risk in patients with primary NPC. The present study aimed to investigate the prognostic value of pretreatment LMR in a large cohort of metastatic NPC patients. Methods: Clinical data of 672 patients with metastatic NPC diagnosed between January 2003 and December 2009 were analyzed. The peripheral lymphocyte and monocyte counts were retrieved, and LMR was calculated. Receiver operating characteristic (ROC) curve analysis and univariate and multivariate COX proportional hazards analyses were performed to evaluate the association of LMR with overall survival (OS). Results: Univariate analysis revealed that an elevated absolute lymphocyte count (>= 1.390 x 10(9)/L) and LMR (>= 2.475) as well as a decreased monocyte count (<0.665 x 10(9)/L) were significantly associated with prolonged OS. Multivariate Cox proportional hazard analysis showed that LMR (hazard ratio [HR] = 0.50, 95 % confidence interval [CI] = 0.41-0.60, P < 0.001), absolute lymphocyte count (HR = 0.77, 95 % CI = 0.64-0.93, P = 0.007), and monocyte count (HR = 1.98, 95 % CI = 1.63-2.41, P < 0.001) were independent prognostic factors. By stratification analyses, only LMR remained a significant predictor of prognosis. Conclusion: We identified pretreatment LMR as an independent prognostic factor for patients with metastatic NPC. Independent validation of our findings is needed.