Short-term prognostic effects of circulating regulatory T-Cell suppressive function and vascular endothelial growth factor level in patients with non-small cell lung cancer and obstructive sleep apnea

To determine if suppressive function of regulatory T-cells (Tregs) and vascular endothelial cell growth factor (VEGF) levels are closely associated with prognosis of patients with non-small cell lung cancer (NSCLC) and obstructive sleep apnea (OSA). Peripheral blood from 20 OSA patients, 44 newly diagnosed NSCLC patients with (n = 22) and without (n = 22) OSA was collected. Forkhead box protien 3 plus (Foxp3+) and CTLA-4+ Tregs ratio were analyzed with flow cytometry. Levels of VEGF, IL-10 and TGF-β1 were analyzed with enzyme-linked immuno sorbent assay. NSCLC patients with and without OSA were followed up for two years. Optimal cutoff values were determined by receiver operating characteristic curves. Survival analysis were performed using the Kaplan–Meier test. NSCLC patients with OSA showed higher Foxp3+Tregs ratio, higher plasma VEGF and TGF-β1 levels when compared with NSCLC patients without OSA (P < 0.05). In NSCLC patients with OSA or not, subjects with higher Foxp3+Treg ratio, higher TGF-β1 and VEGF levels tended to have poor mean survival time and two-year overall survival (OS, Foxp3+Treg: 636.7 vs. 704.8 days, 59.0% vs. 82.6%, P = 0.125; TGF-β1: 637.8 vs. 698.4 days, 57.0% vs. 84.4%, P = 0.054; VEGF: 642.9 vs. 677.5 days, 48.6% vs. 81.3%, P = 0.074). Multivariate Cox regression adjusted for disease stage and receipt of systemic treatments, confirmed the links between high VEGF level and worse OS (HR: 1.003; 95% CI: 1.001–1.005; P = 0.021). OSA may up-regulate the expression of circulating TGF-β1, VEGF and Foxp3+Tregs expression in NSCLC patients. Elevated VEGF level is closely associated with worse short-term survival in NSCLC patients with OSA or not.