Predictive value of E-cadherin and Ep CAM for detection of metastatic lymph node in early gastric cancer

Objective:There has been a demand for a tumor-specific marker for metastatic lymph nodes in sentinel navigation surgery for gastric cancer.The aim of this study is to analyze protein expression in both primary tumors and metastatic lymph nodes in early gastric cancer patients.Methods:We collected primary tumors and metastatic lymph nodes from 71 patients who underwent curative gastrectomy and pathologically diagnosed with T1 N1 or T1 N2(8 th Union for International Cancer Control 8 th edition/American Joint Committee on Cancer staging system)gastric cancer.Immunohistochemistry was used to determine the expression of six cell membrane proteins,including carcinoembryonic antigen(CEA),E-cadherin,epithelial cell adhesion molecule(Ep CAM),P-cadherin,CD44 v6,and c-erb B2 in the patient samples.Results:The expression of CEA,E-cadherin,Ep CAM,P-cadherin,CD44 v6 and c-erb B2 in the evaluable primary tumor samples was 75.4%,97.1%,100%,89.9%,11.1%and 7.2%,respectively.Among cases wherein both the primary tumor and metastatic lymph nodes were evaluable,double positivity(expression in both primary tumor and metastatic lymph nodes)was observed for CEA,E-cadherin,Ep CAM,P-cadherin,CD44 v6 and c-erb B2 in 53.2%,97.9%,98.1%,76.6%,0 and 6.8%of the cases,respectively.The proportion of metastatic lymph nodes positive for CEA,E-cadherin,Ep CAM,P-cadherin,CD44 v6 and c-erb B2 was 71.4%,100%,98.1%,83.7%,0,and75%,respectively in primary tumors positive for the same markers.Conclusions:E-cadherin and Ep CAM had an overlap of 100%and 98.1%between the primary tumor and metastatic lymph nodes,respectively.Thus,E-cadherin and Ep CAM are potential molecular markers to detect metastatic lymph nodes in patients with early gastric cancer.