Detection of CK19 mRNA and CEA mRNA in peritoneal washings for predicting peritoneal micrometastasis in patients with gastric carcinoma

Objective:To explore a method for predicting peritoneal micrometastasis in gastric carcinoma patients. Methods: Peritoneal washings of 67 patients with gastric carcinoma and 9 patients with benign gastric diseases were collected to detect the mRNA level of CK19,CEA and CK20 by nest reverse transcription-polymerase chain reaction (RT-PCR). The protein level of CEA(P-CEA) was detected by time resolved fluoroimmunoassay(TRF). The peritoneal lavage cytology examinations (PLC) were carried out by H-E staining.Results: The positive rates of CK19 mRNA, CEA mRNA and CK20 mRNA in peritoneal washings were 62.7%, 52.2% and 34.3%,respectively. The positive rates of CK19 mRNA and CEA mRNA were significantly higher than those of P-CEA (35.8%) and PLC (31.3%). The positive rates of CK19 mRNA and CEA mRNA were concurrently increased with the depth of tumor invasion, TNM staging and degree of peritoneum involvement. Conclusion: Detecting CK19 mRNA and CEA mRNA in peritoneal washings by nest RT-PCR can improve the sensitivity of free tumor cell detection in peritoneal washings,and may be used to predict peritoneal micrometastasis of gastric carcinoma.