Abstract 2306: The prognostic impact of epithelial mesenchymal transition markers in primary diffuse gastric carcinoma and their relative lymph nodes

Abstract

Abstract Background: The accumulating evidences for epithelial mesenchymal transition (EMT) are important in experiments conducted in cell culture and rodents. However, pathologists still debate the existence of EMT and its impact on cancer progression. The purpose of this present study was to investigate the distribution of EMT biomarkers in primary diffuse gastric carcinoma (DGC) and their relative lymph nodes (LN) and to correlate them with clinical outcome. Patients and methods: The study included 51 consecutive patients who underwent surgical resection in our institution between January 1991 and December 2007 for DGC. A tissue-microarray was constructed using paraffin-embedded tissues from gastrectomy (n=51) and matched LN (n=37). Expression of c-MET, E-cadherin, cytokeratin and vimentin were assessed by immunohistochemistry (IHC) in primary DGC, their relative LN and non-tumoral adjacent tissues. Results: Membranous c-Met overexpression was found in 32% of primary DGC and 38% of LN. Membranous E-cadherin expression was found in 70% of both primary CDG and LN. All tumors expressed cytokeratin and there was no expression for vimentin neither in primary DGC nor in their relative LN. Although there was a high correlation in E-cadherin expression between primary DGC and their relative LN (r2 = 0.93), a poor correlation for c-MET expression (r2 = 0.02) was found. Univariate analysis for recurrence-free survival (RFS) and overall survival (OS) were performed for the following parameters: TNM stage, c-MET and E-cadherin expression both in primary DGC and their matched LN. LN overexpression of c-MET was the only prognostic factor for better relapse-free survival (RFS) (HR= 2.82, CI95%:1.27-6.85) and overall survival (OS) (HR= 2.41, CI95%:1.05-5.52) for the entire cohort. Conclusions: Our findings indicated that c-MET overexpression did not correlate between primary DGC and their relative LN and that only LN c-MET overexpression had a prognostic impact. Conversely, there was a high correlation between E-cadherin, vimentin, and cytokeratin expression between the primary DGC and their relative LN. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2306.