RESUMEN
This study aims to investigate the value of the combined detection of carcinoembryonic antigen (CEA), Neuron-specific enolase (NSE) and the level of Interleukin-18 (IL-18) in the serum in the diagnosis of lung cancer. The correlation between these parameters and the expression levels of B-cell lymphoma-2 (Bcl-2) protein were also studied. Eighty patients with lung cancer were included in the lung cancer group. These patients underwent surgery in the Department of Oncology of Huai'an Second People's Hospital between February 2016 and February 2018. During the same period, another 80 patients with benign lung lesions were registered in the benign lesion group and 80 healthy people were enrolled in the control group. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression levels of CEA, NSE and IL-18. The diagnostic critical value of these factors was used as positive indicator. When CEA, NSE and IL-18 levels were positive at the same time, the combined detection was considered to be positive. WB was used to detect Bcl-2 expression level. We also analyzed the possible correlation between CEA, NSE, IL-18 levels and the Bcl-2 expression levels. The CEA, NSE and IL-18 expression levels in the serum of the lung cancer group were significantly higher than those in the benign lesion and the control groups (p<0.05). The area under ROC curve for CEA, NSE and IL-18 respectively was 0.770 (0.697-0.843), 0.829 (0.767-0.890), 0.721 (0.642-0.800) (p<0.001). IL-18 level was negatively correlated with the level of Bcl-2 mRNA in the tissue (r=-0.380, p<0.001). In conclusion, CEA, NSE and IL-18 have a good auxiliary diagnostic value in patients with lung cancer. The combined detection could improve the sensitivity and specificity of lung can¬cer diagnosis. There was a negative correlation between IL-18 and Bcl-2 levels which suggested a potential inhibitory role of IL-18 on the lung cancer cells apoptosis pathway.