Role of platelet infiltration as independent prognostic marker for gastric adenocarcinomas

BACKGROUND: In recent years, the relationship between malignant tumors and platelets has been paid more attention. The increase of platelets is an independent risk factor for the poor prognosis of some malignant tumors. METHODS: This study retrospectively analyzed the clinical and pathological data of 114 patients with initial gastric cancer from August 2005 to August 2018 in Shandong Provincial Hospital. Single‐factor and multifactor survival analysis were used to evaluate the effect of platelet elevation on postoperative survival. The gastric cancer tissues of the Jinan Central Hospital and its matched paracancerous tissues were collected. The expression of platelets in tissues was detected by immunofluorescence technique. Different numbers of platelets were co‐cultured with MKN‐45 cells, CCK‐8 assay and transwell assay were performed, and the expression of epithelial‐mesenchymal transition‐related proteins was detected. RESULTS: Platelet count was independent factors affecting prognosis. The stratified analysis showed that there was a statistically significant difference in the 5‐year survival rate between the platelet‐increase group and the normal platelet group in the TNM stages I‐II. The expression of platelets in gastric cancer tissues was higher than that in adjacent tissues. The results of CCK‐8 and transwell showed that platelets significantly enhanced the proliferation and metastasis capability of MKN‐45 cells in a concentration‐dependent manner. After co‐culture, the expression level of E‐cadherin protein in MKN‐45 cells decreased, and the protein expression levels of N‐cadherin, vimentin, and VEGFA increased. CONCLUSION: Platelet elevation is closely related to the occurrence, development, and metastasis of gastric cancer, and platelet count can be used as a prognostic indicator for malignant tumors.