The Expressions And Clinical Significance Of EGFR And PEGFR In Non-small Cell Lung Cancer

Background:In recent years, the morbidity and mortality of lung cancer increased rapidly to the top position in the tumors. Although Clinical laboratory examinations and treatment programs continuously improved, the five-year survival rate of lung cancer patients is still less than 15%. With the deep study of molecular mechanisms of lung cancer,molecular targeted therapy has been widely used in clinical. In these molecular targeted drugs, most attention is put on the epidermal growth factor receptor inhibitors, but their overall effect on lung cancer is still very low. In addition the cost is very high, so it is necessary to find the right lung cancer patients who will benefit from EGFR-TKI.Epidermal growth factor receptor-tyrosine kinase inhibitor(EGFR-TKI) therapeutic target is the EGFR protein, and EGFR protein changes into phosphorylated epidermal growth factor(pEGFR) after activation, and in turn activating a series of signal transduction pathways downstream proteins in the nucleus, and thus mediated tumor cell proliferation, differentiation, invasion, angiogenesis, adhesion, metastasis and inhibition of apoptosis. However, currently, only as low as 30% lung cancer patients could benefite from EGFR-TKI.In this study, immunohistochemistry was used to detect EGFR, pEGFR protein in non-small cell lung cancer. The relationship between the above proteins and clinicopathological features was also analized .Purpose:To investigate EGFR, pEGFR protein expressions in NSCLC tissues and adjacent normal lung tissue, and the association between EGFR protein and the pEGFR. And to analyze the relationship between the proteins and pathological and clinical features, At last, tried to find the their significance during the occurrence, development and treatment of lung cancer.Method:Lung tissues were fixed with 10% neutral formalin, paraffin-embedded, cut into 4μm thick serial sections, undergoing routine HE staining and immunohistochemistry staining for measueing EGFR and pEGFR protein expression in 140 cases of NSCLC tissues and adjacent normal lung tissues.Results:In 140 cases of NSCLC, positive expressions of EGFR and pEGFR protein were 60.7%(85/140) and 29.3%(41/140) respectively,and significantly higher than that in 140 cases of adjacent normal lung tissue corresponding the lung cancer(6.4%(9/140)positive staining for EGFR and 1.4%(2/140) positive sataining for pEGFR).(each P<0.05). The expression of EGFR in lung cancer has no relationship with patient's age, gender, smoking and tumor's histological type,differentiation,tumor size, TNM stage and lymph node metastasis (P>0.05). While pEGFR protein expression was correlated with patient's gender, smoking and tumor's histological type respectively ( P<0.05 ) ,but not patient's age, differentiation,tumor size, TNM stage and lymph node metastasis(P>0.05).In addition, there was no correlations between EGFR and pEGFR protein.Conclusion:1. The expression of EGFR, pEGFR protein in lung cancer were higher than that in their corresponding adjacent normal lung tissue. 2. The EGFR, may activate its signal transduction pathways of downstream proteins through its active form pEGFR , and maybe a target in lung cancer treatment. Therefore, the development of lung cancer might be inhibited by blocking EGFR, pEGFR.3. The abnormally high expression of pEGFR protein in NSCLC may help to find some hint of predicting the efficacy of EGFR-TKI treatment and screening of the object.