Levels of Circulating Microparticles in Lung Cancer Patients and Possible Prognostic Value

BACKGROUND Endothelial-derived microparticles (EDMPs) and platelet-derived microparticles (PDMPs) have been reported to be increasing in various diseases including malignant diseases. Here, we investigated whether these MPs may be useful biomarkers for predicting lung cancer (LC) disease status, cell type, or metastasis. METHODS AND RESULTS One hundred and thirty LC patients were prospectively enrolled into the study between April 2011 and February 2012. Flow cytometric analysis demonstrated that the circulating levels of platelet-derived activated MPs (PDAc-MPs), platelet-derived apoptotic MPs (PDAp-MPs), endothelial-derived activated MPs (EDAc-MPs), and endothelial-derived apoptotic MPs (EDAp-MPs) were significantly higher in LC patients than in 30 age- and gender-matched normal control subjects (all P < 0.05). Additionally, circulating level of PDAc-MPs was significantly lower (P = 0.031), whereas the circulating levels of the other three biomarkers did not differ (all P > 0.1) in early stage versus late stage LC patients. Furthermore, the circulating levels of the four types of MPs did not differ among patients with different disease statuses (i.e., disease controlled, disease progression, and disease without treatment, i.e., fresh case) (all P > 0.2) or between patients with or without LC metastasis (all P > 0.5). Moreover, only the circulating level of EDAp-MPs was significantly associated with the different cell types (i.e., squamous cell carcinoma, adenocarcinoma, and small cell carcinoma) of LC (P = 0.045). CONCLUSION Circulating MP levels are significantly increased in LC patients as compared with normal subjects. Among the MPs, only an increased level of EDAp-MPs was significantly associated with different LC cell types.