Detection Of Expression Of CEA MRNA And CK19 MRNA By RT-PCR In The Peripheral Blood Micrometastasis In Patients With Non-Small Cell Lung Cancer

Objective:(1) To detect and comparatively analyse the expression of carcinoembryonic antigen mRNA (CEA mRNA) and cytokeratin 19 mRNA (CK19 mRNA) in peripheral blood of non-small lung cancer (NSCLC) patients.(2) To investigate the possibility of CEA mRNA and CK19 mRNA as a biomarker for diagnosis of micrometastasis in patients with NSCLC.Methods:(1) 48 NSCLC patients samples and 15 benign lung disease (BLD) patients samples and 10 healthy volunteers samples from peripheral blood were selected randomly.(2) The expressions of CEA mRNA and CK19 mRNA were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) in peripheral blood of 48 NSCLC patients,15 BLD patients and 10 healthy volunteers. The correlation analysis was compared between CEA mRNA and CK19 mRNA expression in the peripheral blood and general clinical characteristics (sex,age,blood type and smoking) and pathological parameters (histology type,pTNM stage,differentiating degree and lymph node metastasis) in NSCLC patients further.Results:(1) The positive expression rate of CEA mRNA and CK19 mRNA was 58.33%(28/48),68.75%(33/48) in peripheral blood in NSCLC group respectively. The BLD group was 6.67%(1/15),13.33%(2/15) respectively. None was detected in control group (0/10), The positive expression rate of CEA mRNA and CK19 mRNA in NSCLC group were both statistically higher than those in the other groups (p<0.05).(2) The positive expression rate of CEA mRNA was 27.8%(5/18),83.3% (10/12),61.5%(8/13),100%(5/5) in peripheral blood in NSCLC of pTNM stageⅠ,Ⅱ,Ⅲ,Ⅳrespectively.it was closely related with the clinical stage (χ2 =13.626, p=0.003) and lymph node metastasis (χ2=20.378, p=0.000).it was no relationship between pathological type (χ2=4.029, p=0.545),tumor cell differentiating degrees (χ2=1.560, p=0.458) and general clinical characteristics (sex,age,blood type and smoking history) with NSCLC patients (p>0.05).(3) The positive expression rate of CK19 mRNA was 44.4%(8/18),75% (9/12),92.3%(12/13).80%(4/5) in peripheral blood with non-small cell lung cancer of pTNM stageⅠ,Ⅱ,Ⅲ,Ⅳrespectively. The positive expression of CK19 mRNA was closely related with the clinical stage (χ2=8.820, p=0.032) and lymph node metastasis (χ2=6.813, p=0.009).but not correlated with pathological type (χ2=4.655, p=0.459),tumor cell differentiating degrees (χ2 =1.204, p=0.548) and general clinical characteristics (sex,age,blood type and smoking history) in NSCLC patients (p>0.05).(4) The positive expression rate was to 81.25%(39/48), when CEA mRNA and CK19 mRNA were used to combined detection in peripheral blood in NSCLC patients.it's sensitivity was higher than that of single detection.But the difference wasn't statistical significance between CEA mRNA and CK19 mRNA expression level for the detection of NSCLC micrometastasis in peripheral blood (χ2=3.017, p=0.082). Conclusion:(1) Even if patients of NSCLC in peripheral blood already have micrometastasis on earlier stage (Ⅰ,Ⅱ), The presence of micrometastases may partly help clinicians to demonstrate the fact that some patients with early NSCLC suffered relapse and distant metastasis shortly.whereas micrometastasis might be one of causes of poor prognosis.(2) Detection of CEA mRNA or CK19 mRNA in peripheral blood might be a proper molecular marker for diagnosis of micrometastasis in patients with non-small cell lung cancer.(3) Combined examination of CEA mRNA and CK19 mRNA expression in peripheral blood can improve the detection positive rates of NSCLC patients.