Predictive and prognostic significance of circulating endothelial cells in advanced non-small cell lung cancer patients

The aim of this study was to evaluate the predictive and prognostic values of circulating endothelial cells (CECs) in patients with advanced non-small cell lung cancer (NSCLC). A total of 102 newly diagnosed advanced NSCLC patients were enrolled in this study. The amount of CECs was enumerated by flow cytometry (CD45- CD31+ CD146+) at baseline. CEC counts of 56 patients were detected before and after two cycles of chemotherapy. We correlated the baseline and reduction of CECs after therapy with objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). The CEC level was significantly higher in advanced NSCLC patients, ranging from 57 to 1300 cells/10(5) cells (mean +/- SD = 299 +/- 221 cells/10(5) cells), than in patients with benign lesions (205 +/- 97 cells/10(5) cells) and healthy volunteers (117 +/- 33 cells/10(5) cells). When the cutoff value of CEC counts was 210 cells/10(5) cells, there was no significant association between CEC counts and OR/PFS/OS of the enrolled patients. However, patients with CEC response after chemotherapy have more chances to achieve OR (P < 0.001), and such patients showed longer PFS (P = 0.048) and OS (P = 0.018) than those without CEC response. In the multivariate analysis, the independent prognostic roles of brain metastasis (HR 6.165, P = 0.001), and CEC response (HR 0.442, P = 0.044) were found. The CEC counts could be considered as diagnostic biomarker for advanced NSCLC patients. And the reduction of CECs after treatment might be more ideal than the baseline CEC counts as a predictive or prognostic factor in patients treated with chemotherapy or anti-angiogenic therapy.