Diagnostic and prognostic values of endothelial-cell-specific molecule-1 with malignant pleural effusions in patients with non-small cell lung cancer

Over-expressed endothelial-cell-specific molecule-1 (ESM-1) in tumor vascular endothelium contributes to tumor angiogenesis, metastasis, and poor prognosis. However, the content of ESM-1 in pleural effusion is unclear. A retrospective study was carried out to investigate the diagnostic and prognostic values of ESM-1 with malignant pleural effusions in patients with non-small cell lung cancer (NSCLC). ESM-1 levels in malignant pleural effusion (MPE) from 70 patients with NSCLC and 50 cases of benign pleural effusion (BPE) were measured using enzyme-linked immunosorbent assay. Receiver operating characteristic (ROC) curve was calculated to assess the diagnostic value of ESM-1. Survival curves were performed by Kaplan-Meier method and survival characteristics were compared by log-rank test. Univariable and multivariate Cox proportional hazards model were carried out to analysis the significance of different prognostic factors for overall survival (OS). ESM-1 levels were significantly higher in MPE than those in BPE (p < 0.001). By ROC curve analysis, with a cutoff level of 19.58 ng/ml, the accuracy, sensitivity, and specificity for ESM-1 diagnosis MPE were 82.5%, 81.4%, and 84.0%, respectively. Moreover, NSCLC patients with pleural fluid ESM-1 levels below 19.58 ng/ml had significant longer OS than those patients with higher levels (22.09 months vs. 11.49 months, p = 0.003). Multivariate survival analysis showed that high MPE ESM-1 level was an independent prognostic factor (HR, 1.007; p = 0.039) for the OS of NSCLC patients. This study showed that ESM-1 level in pleural effusion could be a potential diagnostic and prognostic marker in NSCLC patients with MPE.