Detection Of Cytokeratin 19 MRNA In Peritoneal Washings Of Gastric Cancer

Objective To detect the expression of cytokeratin 19 (CK 19) mRNA in the peritoneal lavage fluid from 36 patients with gastric cancer by using real-time fluorescent quantitative reverse transcription-polymerase chain reaction (FQ-RT-PCR), and to explore the relationship between CK19 mRNA expression and clinical pathology of gastric cancer, thereby provid-ing a novel technique for the prediction of peritoneal micro-metastasis and the screening of the subclinical metastasis of gastric cancer.Method CK19 mRNA expressions in the peritoneal lavage fluid were detected in 36 gastric cancer patients by RNA extraction and FQ-RT-PCR technique. Meanwhile, the HE staining and peritoneal lavage cytology (PLC) examination were performed. Peritoneal lavage fluids from eight cases with benign lesions were used as negative controls; and gastric cancer tissues from eight patients were used as positive controls.Results The positive rate of CK19 mRNA expressions in peritoneal lavage from 36 gastric cancer patients'was 61.1%(22/36), which was significantly higher than the result of 22.2%(8/36) by PLC examination (P=0.020). Moreover, the eight patients with positive PLC results had positive CK19 mRNA expressions, and of the 28 patients with negative PLC results,14 had positive CK19 mRNA expressions. The expression levels of CK 19 mRNA in the peritoneal lavage fluid from gastric cancer patients were associat-ed with infiltration depth, lymph node metastasis, TNM staging and PLC results. In contrast, both CK19 mRNA expressions and PLC results were negative in the eight patients with benign lesions. The eight positive controls also had positive CK19 mRNA expressions, and the quantitative value is much higher than peritoneal lavage fluid.Conclusion CK19 mRNA expression in the gastric cancer peritoneal lavage fluid is closely associated with the peritoneal metastasis of the cancer. The measurement of CK19 mRNA expression in peritoneal lavage fluid with FQ-RT-PCR can improve the sensitivity of detecting exfoliated cancer cells (ECC) in the peritoneum, which therefore is applicable to the prediction of peritoneal micro-metastasis and the screening of the subclinical metastasis of gastric cancer, and the technique can further guide the clinical evaluation and management of gastric cancers.