Correlation Between Lung Specific X Protein MRNA As A Micrometastasis Marker In Lymph Nodes And The Prognosis Of Patients With Stage Ⅰ Non-small Cell Lung Cancer

Objective:We aim at studying the expression of lung specific X protein mRNA as a micrometastasis marker in N1and N2lymph nodes using real-time quantitative polymerase chain reaction (RT-PCR), and analyzing the correlation between LUNX mRNA in lymph nodes and the prognosis of patients with stage I non-small cell lung cancer.Methods:One hundred and sixty patients with pathologically stage I who accepted completely surgical lung resection and lymph nodes dissection were selected from2005-2010. LUNX mRNA was detected as a micrometastasis marker in the tumor, hilar (N1) lymph nodes and subcarinal(N2) lymph nodes using real-time quantitative PCR in160patients with pathologically stage I NSCLC. The correlation between tumor sizes, pathological stage, prognosis and the expression of LUNX mRNA in Nl and N2lymph nodes was analyzed.Results:LUNX mRNA were found in all the tumor tissue in160patients, while no LUNX mRNA expression was found in lymph nodes of ten patients with benign disease. Nineteen lymph nodes were detected with LUNX mRNA expression in160N1lymph nodes, including twelve lymph nodes from patients with adenocarcinoma and seven lymph nodes from patients with squamous cell carcinoma. Six of nineteen lymph nodes came from patients with pathologically stage IA, while thirteen of nineteen lymph nodes came from patients with pathologically stage IB. Seventeen lymph nodes were detected with LUNX mRNA expression in160N2lymph nodes, including fourteen lymph nodes from patients with adenocarcinoma and three lymph nodes from patients with squamous cell carcinoma. Five of seventeen lymph nodes came from patients with pathologically stage IA, while twelve of seventeen lymph nodes came from patients with pathologically stage IB. Seven cases with adenocarcinoma were detected LUNX mRNA expression in both N1 and N2lymph nodes. Two of seven were in pathologically stage IA, while others were in pathologically stage IB. Statistical analysis showed that the ratio of lymph node micrometastasis in patients with adenocarcinoma was significantly higher than in patients with squamous cell carcinoma. The ratio of lymph node micrometastasis in patients in pathologically stage IB was significantly higher than in patients pathologically stage IA. The ratio of N2lymph node micrometastasis in patients with adenocarcinoma was significantly higher than in patients with squamous cell carcinoma. The ratio of N2lymph node micrometastasis in patients in pathologically stage IB was significantly higher than in patients pathologically stage IA. Compared with patients with squamous cell carcinoma, patients with adenocarcinoma were higher rate of N2lymph node micrometastasis. Survival analysis showed that the survival rate in patients of lymph node micrometastasis was lower than patients without lymph node micrometastasis. Patients with lymph node micrometastasis had bad prognosis. N1lymph node micrometastasis does not affect the survival rate, while N2lymph node micrometastasis affect the survival rate significantly, there is no difference in survival rates in patients with both N1and N2lymph nodes micrometastasis and only N2lymph node micrometastasis.Conclusions:The ratio of lymph node micrometastasis in patients with adenocarcinoma was higher than squamous cell carcinoma. The ratio of lymph node micrometastasis in patients in IB was higher than IA. The ratio of N2lymph node micrometastasis in patients with adenocarcinoma was significantly higher than squamous cell carcinoma. N1lymph node micrometastasis does not affect the survival rate, while N2lymph node micrometastasis affect the survival rate significantly. There is no difference in survival rates in patients with both N1and N2lymph nodes micrometastasis and only N2lymph node micrometastasis. Adenocarcinoma and IB stage patients had poorer prognosis than squamous cell carcinoma and IA stage patients because of lymph node especially N2lymph node micrometastasis.