Background/aims: To investigate the significance of pathological factors for formation, molecular characterization and prognosis of free gastric cancer cells in the peritoneal cavity.
Methodology: The peritoneal lavage fluid of 132 patients with gastric cancer (invasion depth < or =T3) was sampled at laparotomy. The detection of free gastric cancer cells was performed by peritoneal lavage cytology (PLC) and detection of cytokeratin 18 (CK18) by immunocytochemistry. The relationship between positive rate of free gastric cancer cells and clinical features was analyzed. The expression of HGF, SP1, VEGF and CD34 were detected in 80 gastric cancer specimens with serosal invasion by immunohistochemistry. Clinical follow-up was performed for all the patients.
Results: The positive rate of free gastric cancer cells by the combination of PLC and immunocytochemistry techniques correlated with tumor size, Borrmann type, differentiation, area, growing pattern, lymph node metastasis and serosal type, but it was not correlated to gender, tumor location, and Lauren type. Positive correlation was observed between microvessel density (MVD) and the expressions of HGF, SP1 and VEGF. The expressions of HGF, SP1 and VEGF and MVD werecorrelated with the clinicopathologic parameters. Single factor analysis showed that the relapse rate of patients receiving gastric cancer radical correction within half a year correlated with the expressions of HGF, SP1 and VEGF, MVD, positive PLC and tumor size.
Conclusions: The combination of PCL and CK18 detection for free gastric cancer cells is sensitive and specific. The positive rate of free gastric cancer cells, expressions of HGF, SP1, VEGF, and MVD correlated with the clinical and pathological factors of gastric cancer. The detection of some relative factors may help to evaluate the stage, and predict the presence of free gastric cancer cells and post-operation relapse.