Prognostic value of absolute lymphocyte count in patients with extranodal nasal NK/T cell lymphoma / 白血病·淋巴瘤

ABSTRACT

Objective:To investigate the relationship between absolute lymphocyte count (ALC) and prognosis of extranodal nasal NK/T cell lymphoma (ENKTL).Methods:The data of 184 patients with ENKTL who were admitted to Shanxi Provincial Cancer Hospital and the Second People's Hospital of Datong in Shanxi Province from January 2002 to December 2018 were retrospectively analyzed. Contal-O'Quigley variable point method was used to calculate the optimal cut-off value of ALC for predicting the prognosis of ENKTL, and the patients were divided into two groups based on this value. Kaplan-Meier method was used to analyze the survival of the two groups of patients. Cox proportional hazard regression model was used for univariate and multivariate survival analyses.Results:According to the Contal-O'Quigley variable point method, the best cut-off value of ALC for predicting ENKTL prognosis was 1.5×10 9/L. According to this value, patients were divided into ALC>1.5×10 9/L group (98 cases) and ALC≤1.5×10 9/L group (86 cases). Compared with the ALC≤1.5×10 9/L group, the proportions of patients with Eastern Cooperative Oncology Group (ECOG) score ≥2 points, serum lactate dehydrogenase (LDH)> 245 U/L, Korean prognostic index (KPI) score 2-4 points and international prognostic index (IPI) score 2-5 points were lower in the ALC>1.5×10 9/L group, but the proportion of patients with hemoglobin > 120 g/L was higher (all P < 0.05). The overall survival (OS) and progression-free survival (PFS) in the ALC>1.5×10 9/L group were better than those in the ALC≤1.5×10 9/L group (3-year OS rate 65.7% vs. 45.4%, 5-year OS rate 61.0% vs. 36.6%; 3-year PFS rate 61.7% vs. 41.0%, 5-year PFS rate 51.9% vs. 32.2%; all P < 0.05). Multivariate Cox regression analysis showed that ECOG score, serum LDH level, ALC, radiotherapy and L-asparaginase-containing chemotherapy were independent influencing factors of OS and PFS (all P < 0.05), and for OS, when ALC>1.5×10 9/L compared with≤1.5×10 9/L, RR was 0.634 (95% CI 0.398-1.008, P=0.050), and for PFS, RR was 0.625 (95% CI 0.406-0.962, P=0.033). Conclusion:Patients with high ALC have good prognosis, and therefore ALC may be a powerful prognostic factor of ENKTL.