BACKGROUNDTo explore the sensitivity and clinical significance of detection of CK19 mRNA and CEA mRNA expression for the diagnosis of micrometastases in the peripheral blood of patients with non small cell lung cancer (NSCLC).

METHODSNested reverse transcription-polymerase chain reaction (RT-PCR) was used to detect CK19 mRNA and CEA mRNA in the peripheral blood of 35 patients with NSCLC. Twenty patients with pulmonary benign lesions and 20 normal healthy volunteers were served as controls.

RESULTSThe positive rates of CK19 mRNA and CEA mRNA for NSCLC patients were 40% (14/35) and 57% (20/35) respectively, 14 cases (40%) were positive for both mRNA, and 15 cases (43%) were both negative for both mRNA. No blood samples from patients with pulmonary benign lesions was positive for CEA mRNA, but 2 samples (10%) were positive for CK19 mRNA. Of these 20 samples from normal volunteers, none was positive for both CK19 mRNA and CEA mRNA. The distant metastasis rate of patients with positive CK-19 mRNA , positive CEA mRNA and both negative in the peripheral blood were 50%, 56% and 27% respectively.

CONCLUSIONSBoth CK-19 mRNA and CEA mRNA are good markers to detect micrometastasis in the peripheral blood of patients with NSCLC. Detection of CK19 and CEA mRNA expression might be helpful to predict the prognosis of patients with lung cancer.