The Expression Of PAK4 In The Tissue And Plasma Of Non-small Cell Lung Cancer And Its Comparison With CEA And CYFRA21-1 In The Serum

Objective: To study the expression of p21 activated kinase 4(PAK4)in tumor tissues and plasma of non-small cell lung cancer(NSCLC),and to determine whether PAK4 has diagnostic value for NSCLC.Methods: The expression of PAK4 in 71 cases of NSCLC tumor tissue and adjacent normal lung tissue was observed through tissue array technology and immunohistochemical staining.The levels of PAK4 in plasma of 45 lung benign tumors,62 lung squamous cell carcinoma and 86 lung adenocarcinoma were assayed using ELISA(Enzyme-Linked Immunosorbnent Assay)kits and its diagnostic efficacy was compared with CEA and Cyfra21-1.Statistical analysis was performed using chi-square test for immunohistochemistry,u test for ELISA,and the ROC curve analysis.Results:(1)The positive rate of PAK4 expressionin cancer tissue(71.8%)was higher than that in normal lung tissue(26.8%),P <0.05,which in the group of lymph node metastasis(81.2%)was also higher than that in the group of non-lymph node Metastasis(52.2%),P <0.05.While,this expression did not show a clear statistical difference in gender,age,pathological type,differentiation,tumor size,and TNM staging.(2)The median concentration of plasma PAK4 in 148 NSCLC patients was 4.08 ng/ml,significantly higher than that of 3.67ng/mL in 45 lung benign tumors patients,and had no significant difference between squamous cell carcinoma and adenocarcinoma.Also,there was no correlation between the plasma level of PAK4 and tumor size,lymph node metastasis,TNM stage,and other clinicopathological factors was observed in the research.The area under the ROC curve(AUC)of PAK4 was 0.628,which was smaller than that of CEA(0.752)and Cyfra21-1(0.721).When 3.86ng/mL was taken as the cut-off value at the maximal Youden index,PAK4 had a sensitivity of 62.3% and a specificity of 65.9%.Conclusion: PAK4 is overexpressed in the tumor tissue of NSCLC and has significant correlation with lymph node metastasis.While in the blood,PAK4 has lower diagnostic efficacy than CEA or Cyfra21-1 and could not benefit from the combined diagnostic model through logistic regression analysis,although the median of PAK4 in NSCLC is higher than in that of benign tumors.