Prognostic significance of peripheral blood absolute lymphocyte count and derived neutrophil to lymphocyte ratio in patients with newly diagnosed extranodal natural killer/T-cell lymphoma

Background: Accumulating evidence suggested that tumor microenvironment and host immune system played important roles in determining the clinical course and outcome of human malignancies. The derived neutrophil to lymphocyte ratio (dNLR) and absolute lymphocyte count (ALC) were demonstrated to act as a prognostic factor in several malignancies. Nevertheless, the prognostic significance of them in extranodal natural killer/T-cell lymphoma (ENKTL) patients has never been explored. Patients and methods: A total of 33 newly diagnosed patients with ENKTL were included in this study. Clinicopathological characteristics were collected and prognostic significance of dNLR and ALC were evaluated. Results: Elevated dNLR and low ALC were both associated with poor survival rates. Patients with dNLR >= 3.6 revealed significantly shorter overall survival (OS) (P=0.001) and progression-free survival (PFS) (P=0.008) than those with dNLR <3.6. Patients with ALC <0.8x10(9)/L had worse OS (P=0.008) and PFS (P<0.001) than those with ALC >= 0.8x10(9)/L. An independent significant association between low ALC and poor clinical outcome in multivariate analysis for OS (HR, 36.023; 95% CI, 2.438-532.243; P=0.009) as well as PFS (HR, 7.698; 95% CI, 1.573-37.679; P=0.012) was identified. Conclusion: In this study, we validated for the first time the prognostic value of dNLR and ALC in ENKTL patients. Elevated dNLR and low ALC were both associated with aggressive tumor process and poor survival. ALC value at diagnosis represented an independent favorable prognostic factor for the clinical outcome of ENKTL patients.