Levels of peripheral blood polymorphonuclear myeloid-derived suppressor cells and selected cytokines are potentially prognostic of disease progression for patients with non-small cell lung cancer.

Polymorphonuclear-MDSC (PMN-MDSC) have emerged as an independent prognostic factor for survival in NSCLC. Similarly, cytokine profiles have been used to identify subgroups of NSCLC patients with different clinical outcomes. This prospective study investigated whether the percentage of circulating PMN-MDSC, in conjunction with the levels of plasma cytokines, was more informative of disease progression than the analysis of either factor alone. We analyzed the phenotypic and functional profile of peripheral blood T-cell subsets (CD3+, CD3+CD4+ and CD3+CD8+), neutrophils (CD66b+) and polymorphonuclear-MDSC (PMN-MDSC; CD66b+CD11b+CD15+CD14-) as well as the concentration of 14 plasma cytokines (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12 p70, IL-17A, IL-27, IL-29, IL-31, and IL-33, TNF-α, IFN-γ) in 90 treatment-naïve NSCLC patients and 25 healthy donors (HD). In contrast to HD, NSCLC patients had a higher percentage of PMN-MDSC and neutrophils (P < 0.0001) but a lower percentage of CD3+, CD3+CD4+ and CD3+CD8+ cells. PMN-MDSC% negatively correlated with the levels of IL1-β, IL-2, IL-27 and IL-29. Two groups of patients were identified according to the percentage of circulating PMN-MDSC. Patients with low PMN-MDSC (≤ 8%) had a better OS (22.1 months [95% CI 4.3-739.7]) than patients with high PMN-MDSC (9.3 months [95% CI 0-18.8]). OS was significantly different among groups of patients stratified by both PMN-MDSC% and cytokine levels. In sum, our findings provide evidence suggesting that PMN-MDSC% in conjunction with the levels IL-1β, IL-27, and IL-29 could be a useful strategy to identify groups of patients with potentially unfavorable prognoses.