P1.17-009 Clinical Significance of Preoperative Neutrophil-Lymphocyte Ratio in Patients with Thymic Epithelial Tumor Undergoing Surgery

Abstract

Preoperative neutrophil-lymphocyte ratio (NLR), which is an inflammatory marker, has been reportedly associated with a poor prognosis in patients with various cancers. This study aimed to investigate the clinical significance of preoperative NLR in patients with surgically resected thymic epithelial tumor. A retrospective review was conducted of 64 patients who underwent surgical resection for thymic epithelial tumor between January 2000 and April 2017. Preoperative NLR was calculated as peripheral blood neutrophil (cells/m3) divided by lymphocyte (cells/m3). Receiver operating characteristic (ROC) curve analysis was performed to identify the optimal value for NLR predicting recurrence. Univariate analysis was performed to assess the association between preoperative NLR and relevant clinicopathological variables. Recurrence-free survival (RFS) after first surgery was calculated using the Kaplan-Meier method. The median follow-up period was 66 months. The patients were 32 men and 32 women with a median age of 60 years. The WHO classification was type A (n=10), AB (n=20), B1 (n=9), B2 (n=12), B3 (n=8), and thymic carcinoma (n=5). The patients were classified into two groups according to preoperative NLR: high NLR (≥2.1, n=29) and low NLR (<2.1, n=35) group. Univariate analysis showed that aggressive histology (B2/B3 and thymic carcinoma) and a lower incidence of myasthenia gravis were significantly correlated with high NLR. The RFS rate of the high NLR group was significantly poorer than that of the low NLR group (5- and 10-year RFS rates: 82.6% vs 93.2% and 48.3% vs 93.2%, p=0.034). Preoperative high NLR value was significantly associated with aggressive histology (type B2/B3 thymoma and thymic carcinoma) and a lower incidence of myasthenia gravis. Preoperative high NLR could be a predictor of poor outcome in patients undergoing surgical resection of thymic epithelial tumor.