Circulating and Tumor Myeloid-derived Suppressor Cells in Resectable Non–Small Cell Lung Cancer

Rationale: Myeloid-derived suppressor cell (MDSC) expansion has been found to play a role in disease progression in patients with cancer. However, the characteristics of MDSCs in lung cancer are poorly understood.Objectives: We prospectively investigated MDSCs and inflammatory factors in tumor and peripheral blood samples from patients with resectable non–small cell lung cancer and studied their correlations with the disease prognosis.Methods: A complex analysis of MDSC subsets and inflammatory mediators was performed using flow cytometry and a Bio-Plex assay.Measurements and Main Results: A significant increase in the frequency of circulating monocytic (M)-MDSCs was observed in the patients with non–small cell lung cancer compared with the healthy donors (HDs). Moreover, the frequencies of M- and polymorphonuclear (PMN)-MDSCs were higher in tumors than in the peripheral blood of the same patients. This accumulation was associated with elevated concentrations of inflammatory mediators involved in MDSC mig...