Circulating Endothelial-Derived Activated Microparticle: A Useful Biomarker for Predicting One-Year Mortality in Patients with Advanced Non-Small Cell Lung Cancer

Background. This study tested the hypothesis that circulating microparticles (MPs) are useful biomarkers for predicting one-year mortality in patients with end-stage non-small cell lung cancer (ES-NSCLC). Methods and Results. One hundred seven patients were prospectively enrolled into the study between April 2011 and February 2012, and each patient received regular follow-up after enrollment. Levels of four MPs in circulation, (1) platelet-derived activated MPs (PDAc-MPs), (2) platelet-derived apoptotic MPs (PDAp-MPs), (3) endothelial-derived activated MPs (EDAc-MPs), and (4) endothelial-derived apoptotic MPs (EDAp-MPs), were measured just after the patient was enrolled into the study using flow cytometry. Patients who survived for more than one year were categorized into group 1 (n = 56) (one-year survivors) and patients who survived less than one year were categorized into group 2 (n = 51) (one-year nonsurvivors). Male gender, incidence of liver metastasis, progression of disease after first-line treatment, poor performance status, and the Charlson comorbidity index were significantly higher in group 2 than in group 1 (all P < 0.05). Additionally, as measured by flow cytometry, only the circulating level of EDAc-MPs was found to be significantly higher in group 2 than in group 1 (P = 0.006). Multivariate analysis demonstrated that circulating level of EDAc-MPs along with brain metastasis and male gender significantly and independently predictive of one-year mortality (all P < 0.035). Conclusion. Circulating EDAc-MPs may be a useful biomarker predictive of one-year morality in ES-NSCLC patients.