ObjectiveTo identify differences in blood routine indicators between lung cancer patients and healthy controls, and between different subgroups of lung cancer patients, so as to improve the early detection of lung cancer prognosis, and provide a basis for risk stratification and prognostic judgment for patients with lung cancer.MethodsThis study enrolled 1 227 patients pathologically diagnosed with lung cancer from December 2008 to December 2013 and 2 454 healthy controls 1∶2 matched by sex and age. The blood routine data of lung cancer patients were collected when they were first diagnosed with lung cancer. Gender and age stratified analysis of blood routine indicators between lung cancer patients and controls were conducted. Comparisons of blood routine indicators among lung cancer patients with different pathological types, stages, and prognosis were performed, followed by Cox regression survival analysis. Normally distributed quantitative variables were presented as mean ± standard deviation and non-normally distributed quantitative variables as medium (lower quartile, upper quartile).ResultsCompared to healthy controls, the counts of platelet [(206.84±80.47) vs. (175.27±55.74)×109/L], white blood cells [(7.04±2.29) vs. (6.08±1.40)×109/L], neutrophil [(4.90±2.08) vs. (3.61±1.07)×109/L], monocyte [0.42 (0.30, 0.54) vs. 0.33 (0.26, 0.42)×109/L], and eosinophil [0.14 (0.07, 0.24) vs. 0.12 (0.07, 0.19)×109/L], as the well as neutrophil-lymphocytes ratio (3.91±2.82 vs. 2.03±0.89) and platelet-lymphocyte ratio (160.35±96.06 vs. 96.93±38.02) in lung cancer patients increased significantly, while the counts of red blood cells [(4.41±0.58) vs. (4.85±0.51)×1012/L] and lymphocyte [(1.49±0.60) vs. (1.93±0.59)×109/L] in lung cancer patients decreased, and the differences were statistically significant (P<0.05). The counts of platelet, red blood cells, white blood cells, neutrophil, and monocyte differed among patients with different pathological types, tumor stages, and prognosis (P<0.05). Neutrophil-lymphocytes ratio and platelet-lymphocyte ratio were higher in squamous cell carcinoma patients than those in other pathological patients, higher in advanced lung cancer patients than those in early stage patients, and higher in dead lung cancer patients than those in survival patients (P<0.05). Neutrophil-lymphocyte ratio was an independent factor affecting the prognosis of lung cancer [hazard ratio=1.077, 95% confidence interval (1.051, 1.103), P<0.001].ConclusionsThe inflammatory index of blood routine indicators are higher in lung cancer patients than those in healthy controls, which indicates that lung cancer is closely related to chronic inflammation. There are significant differences in blood routine inflammation index among lung cancer patients with different pathological types, stages, and prognosis, which reflects the heterogeneity and complexity of lung cancer. Neutrophil-lymphocytes ratio inverse correlates with the prognosis of lung cancer.