Detection of Micrometastasis in Lymph Nodes and Its Prognostic Significance in Patients with PN_0 Gastric Cancer

Objective To evaluate the clinicopathologic significance of the detection of cytokeratin expression with immunohistochemical staining in the diagnosis of micrometastasis in regional lymph nodes in patients with gastric cancer.Methods 374 lymph nodes from 39 gastric cancer patients,diagnosed with no lymph node metastasis with routine hematoxylin and eosin(HE) stains,were examined immunohistochemically for the micrometastases of lymph nodes using anti-cytokeratin 19 monoclonal antibody.Results Lymph node micrometastases were observed in 13 of the 39 patients(33.3%),17(4.5%) of the 374 lymph nodes.No significant correlation was observed between micrometastases and other clinicopathological characteristics(P0.05).Analysis of overall survival rate showed significant difference between groups with and without micrometastases in lymph nodes(P=0.0273).Multivariate analysis indicated that micrometastases were an independent progrostic factor.Conclusion Immunohistochemical staining using anti-cytokeratin 19 monoclonal antibody is more sensitive than routine histology for detecting micrometastasis in lymph nodes.The clinical stage based on the micrometastasis is more accurate than that based on routine pathology.Lymph node micrometastases play an important role in the prognosis of gastric cancer.