OBJECTIVETo investigate the correlation of mRNA expression level of three cancer-associated genes-LUNX mRNA, CK19 mRNA and CEA mRNA with metastasis in lymph nodes and histopathological staging in non-small cell lung cancer (NSCLC).

METHODSFifty-six tumor tissue samples and 103 regional lymph node samples were obtained from 56 patients with NSCLC, and another 35 lymph node samples as control from 15 patients with benign pulmonary diseases. The mRNA expression of LUNX, CK19 and CEA genes was detected in these samples by semi-quantitative RT-PCR analysis (reverse transcriptase polymerase chain reaction), meanwhile, all lymph nodes were also examined by conventional pathological method.

RESULTSmRNA expression of LUNX, CK19 and CEA genes in the regional lymph nodes of NSCLC was significantly higher than that in those of benign lung diseases (P < 0.05). Compared with conventional pathological method, RT-PCT was more sensitive (P < 0.05). No significant correlation was found between positive mRNA expression of LUNX mRNA and CK19 mRNA in the lymph nodes and histopathologic type of lung cancer (P > 0.05). But positive expression rate of CEA mRNA in the lymph nodes from adenocarcinoma patients was significantly higher than that in these from squamous cell carcinoma and other types of NSCLC (P < 0.05). The expression level of LUNX mRNA in the lymph nodes was positively correlated with TNM stages.

CONCLUSIONLUNX mRNA and CK19 mRNA may serve as a molecular marker for detection of lymph node micrometastasis in patient with non-small cell lung cancer, but LUNX mRNA is superior to CK19 mRNA in both sensitivity and specificity.