Prediction of peritoneal recurrence by the mRNA level of CEA and MMP-7 in peritoneal lavage of gastric cancer patients

A number of tumor markers had been reported to be useful in detecting free cancer cells in the peritoneal cavity and predict peritoneal recurrence in gastric cancer patients. The objective of this study was to compare the clinical impact of different tumor markers in peritoneal lavage fluid using the real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) technique and to screen the most effective ones from them. The peritoneal lavage fluid of 116 patients with gastric cancer was sampled at laparotomy. After RNA extraction and reverse transcription, real-time quantitative polymerase chain reaction (PCR) was performed using the primers and probes for carcinoembryonic antigen (CEA), cytokeratin-20, matrix metalloproteinase-7 (MMP-7), carbohydrate antigen 125, and transforming growth factor-beta-1. Among the 116 patients, 45 (38.8 %) were confirmed to have peritoneal recurrence. Any of the PCR-positive results of the five tumor markers could predict peritoneal recurrence in the univariate analysis (P < 0.001). In the multivariate analysis, the PCR results of CEA (P = 0.003) and MMP-7 (P = 0.028) were found to be independent prognostic factors. A real-time quantitative RT-PCR analysis of the CEA and MMP-7 transcripts in peritoneal lavage fluid could effectively predict peritoneal recurrence in advanced gastric cancer patients who underwent a potentially curative resection.