Detection of expression of LUNX,CK19 and CEA mRNA in lymph nodes' micrometastasis in patients with non-small cell lung cancer:a comparative analysis

Objective The expression of lung specific X protein(LUNX),cytokeratin 19(CK19) and carcinoembryonic antigen(CEA) message RNA in non-small cell lung cancer(NSCLC) was examined to prove the significance in the carcinogenesis,metastasis and prognosis of NSCLC.Methods Expression of LUNX,CK19 and CEA message RNA were detected in 56 tumor tissues and 103 regional lymph nodes taken from 56 patients with NSCLC,35 lymph nodes from 15 patients with pulmonary benign diseases as controls by semi-quantitative analysis with reverse transcriptase polymerase chain reaction(RT-PCR).Meanwhile,all lymph nodes were also examined by conventional pathological method.Results(1)The expression of LUNX mRNA,CK19 mRNA and CEA mRNA were significantly higher in the regional lymph nodes of NSCLC than in that of benign lung diseases.(2) Compared with conventional pathological method,RT-PCT had superior sensitivity.(3) For LUNX mRNA and CK19 mRNA,no correlation was found between positive rates of micrometastasis with any of the histopathologic type of lung cancer;but the positive rate of CEA mRNA in adenocarcinoma was significantly higher than in any other types of NSCLC.(4) The positive rate of LUNX mRNA in lymph nodes increases along with the stage of TNM.Conclusions The results suggest that the detection of LUNX mRNA and CK19 mRNA might be helpful to diagnose NSCLC micrometastasis in lymph nodes.LUNX is superior to CK19 both in sensitivity and specificity.The establishment of this method may lead to earlier diagnoses of metastasis of lung cancer and treatment of patients with subclinical metastasis in regional lymph nodes.