Clinical Significance of Serum and Tumor Tissue Endostatin Evaluation in Operable Non-small Cell Lung Cancer

Endostatin, as the most potential antiangiogenic factor, is a naturally occurring fragment of collagen XVIII in bloodstream capable of inhibiting tumor growth and metastasis. This study was conducted to explore the clinical value of endostatin in serum and tumor tissue in patients with operable non-small cell lung cancer (NSCLC). ELISA and immunohistochemistry were applied to detect the expression of endostatin in serum and tumor tissue in 105 patient-matched operable NSCLC patients. The serum level of endostatin was significantly higher in NSCLC patients than healthy individuals (P=0.0018). Cases with poorer differentiation showed a higher endostatin serum level (P=0.008). There was no significant correlation between tumor tissue expression and clinical parameters, such as TNM stage, differentiation degree, histological type and lymph node invasion status. A stronger expression of endostain in tumor tissue was associated with a higher serum level (r=0.223). The univariate and multivariate analyses with Cox proportional hazards model for overall survival showed that tumor stage and node status were independent prognostic factors, whereas neither endostatin levels in serum nor in tumor tissue showed potential in predicting the long-term survival of operable NSCLC patients. In conclusion, the results observed in the present study did not support the prediction of overall survival in operable NSCLC based on the expression levels of endostatin in serum and tumor tissue.