ROC curves for serum difference adipocytokines in untreated patients with lung cancer. Evaluation of sensitivity and specificity of adipocytokines in the diagnosis of lung cancer. The area under the ROC curve of serum IGFBP-1, TNF RI, VEGF, TNF RII, PAI-1 and IL-6 for the diagnosis of lung cancer are 0.961, 0.961, 0.829, 0.803, 0.789 and 0.783 (95% CI: 0.880–1.041, 0.893–1.028, 0.672–0.986, 0.636–0.969, 0.590–0.989 and 0.592–0.974. P<0.05), the best cut-off point (according to Youden index) for circulating adipocytokines levels were 0.32, 0.83, 0.65, 0.72, 0.73 and 0.68 pg/mL, and the sensitivity and specificity of diagnosis of lung cancer were more than 70%. ROC, receiver operating characteristic; IGFBP-1, insulin-like growth factor binding protein 1; TNF, tumor necrosis factor; VEGF, vascular endothelial growth factor; IL, interleukin; BDNF, brain-derived neurotrophic factor; PAI-1, plasminogen activator inhibitor-1.