The Advantages And Significance Of CK Staining For Detecting Lymph Node Micrometastasis And Isolate Tumor Cell Of Gastric Cancer

Purpose:The aim of this study was to identify a suitable method for detecting lymph node metastasis of gastric cancer (GCA) by hematoxylin and eosin (HE) and immunohistochemical (IHC) staining.Method:We investigated lymph node metastasis using hematoxylin and eosin (HE), pan-cytokeratin (CK) and epithelial membrane antigen (EMA) IHC staining in741intestinal and657diffusing type GCA lymph nodes.Results:the metastasis rates were significantly different when using conventional HE staining only comparing when using CK or EMA (P<0.01). The metastasis rate of the intestinal type was higher by3.6%(colon type, P<0.01) and9.4%(diffusing type, P<0.01) using CK staining than HE staining. The sensitivity and specificity of CK staining are100%. The lymph nodes detected positive using EMA staining is101(colon type, P<0.01) and76(diffusing type, P<0.01) more than using HE staining only. The sensitivity of colon type is97.2%, while the specificity is80.6%. The sensitivity of diffusing type is85.8%, while the specificity is88.0%. CK staining gets higher diagnostic efficiency than HE and EMA staining. According to T grade, CK staining for lymph nodes of T4clon type and T1,4diffusing type is valuable. According to TNM grade, CK staining for lymph nodes of TNM Ⅲ-Ⅳ colon type and TNM II-IV diffusing type is valuable. According to pathological grade, CK staining for lymph nodes of grade Ⅱ colon type and grade Ⅱ-Ⅲ diffusing type is valuable. Evaluating the TNM stage again after CK staining, totally15patients’TNM stage changes, occupying15.15%. Two patients should have taken post-operative radiochemotherapy, occupying9.09%of those who don’t need further treatment.Conclusion:Because of a high false positive and negative rate of EMA staining, it is not suitable for a clinical diagnose usage. While CK staining can improve the detection rate of positive metastasis lymph nodes, particularly micrometastasis and isolated tumor cells. It could help accessing TNM staging more precisely, providing more specific evidence for diagnosis and choosing of radiochemotherapy.