Abstract: Objective  To investigate the difference of neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR) and carcinoembryonic antigen (CEA) in peripheral blood of patients between lung adenocarcinoma and benign lung disease and their diagnostic values in lung adenocarcinoma. Methods  A total of 91 patients with lung adenocarcinoma admitted to Anhui Chest Hospital from January 2015 to September 2018 were collected as lung adenocarcinoma group and 105 patients with benign lung diseases as control group. The levels of NLR, PLR and CEA in peripheral blood of patients were measured by automatic blood analyzer and immunofluorescence quantitative method. The receiver operating characteristic (ROC) curve and area under curve (AUC) were used to analyze the diagnostic value of the above indicators for lung adenocarcinoma. Results  The NLR and PLR of 91 patients with lung adenocarcinoma were 4.94±0.34 and 306.99±12.56 respectively, which were significantly higher than those of the control group ［2.80±0.13 (t=5.882, P<0.001) and 161.98±5.07 (t=10.710, P<0.001)］. The concentration of CEA in lung adenocarcinoma group was (32.71±5.41) ng/ml, which was higher than that in the control group ［(3.21±0.21) ng/ml, t=5.453, P<0.001］. NLR was 5.74±0.49 in patients with stage ⅢⅣ, significantly higher than 3.59±0.26 in patients with stage Ⅰ-Ⅱ (t=-3.904, P<0.001). PLR was 347.59±14.33 in patients with stage Ⅲ-Ⅳ, higher than 238.94±18.53 in patients with stage Ⅰ-Ⅱ (t=-4.639, P<0.001). The concentration of CEA was (43.18±8.09) ng/ml in patients with stage Ⅲ-Ⅳ, significantly higher than (15.14±3.49) ng/ml in patients with stage Ⅰ-Ⅱ (t=-3.181, P=0.002). The ROC curve analysis showed that the sensitivity, specificity and accuracy of NLR in the diagnosis of lung adenocarcinoma were 72.50%, 65.70%, 71.42% when 3.05 was the value of cut-off, those of PLR were 83.50%, 81.00%, 83.95% when 202.41 was the cut-off, those of CEA were 85.20%, 89.50%, 86.42% when cut-off was 5.92 ng/ml, and those of the combined detection were 87.90%, 95.20%, 89.01%. The sensitivity, specificity and accuracy of the four methods were significantly different (χ2=16.161, P<0.001; χ2=5.984, P=0.014; χ2=5.809, P=0.016). The sensitivity of the combination was higher than that of NLR alone (χ2=6.787, P=0.009), the specificity of the combination was higher than that of NLR and PLR alone (χ2=23.408, P<0.001; χ2=5.879, P=0.015), and the accuracy of combined detection was significantly higher than that of single detection (χ2=8.865, P=0.003; χ2=6.665, P=0.010; χ2=4.670, P=0.031). The AUC of CEA was 0.900 (95%CI: 0.849-0.938), which was significantly higher than NLR′s 0.752 (95%CI: 0.686-0.811), and there was no significant difference between CEA′s 0.900 and PLR′s 0.865 (95%CI: 0.809-0.910). The AUC of the combined detection was 0.940 (95%CI: 0.897-0.969), which was significantly higher than that of NLR (Z=5.565, P<0.001), PLR (Z=3.252, P=0.007), and CEA (Z=2.109, P=0.035). Conclusion  The levels of NLR, PLR and CEA in lung adenocarcinoma are significantly increased, and they are related to staging. The combination detection of the three has the better diagnostic efficacy in lung adenocarcinoma, which is worth for further clinical promotion.

Key words: Lung neoplasms, Adenocarcinoma, Carcinoembryonic antigen, Neutrophil to lymphocyte ratio, Platelet to lymphocyte ratio