[Detection and significance of lymph node micrometastases in patients with histologically node-negative gastric carcinoma].

OBJECTIVE: To study micrometastasis in lymph nodes from patients with node-negative gastric carcinoma according to routine histologic examination and its relevance to prognosis. METHODS: A total of 1,245 perigastric lymph nodes histologically free of metastasis from 105 patients were immunohistochemically stained with monoclonal antibody AE1 against low molecular weight cytokeratin for micrometastases. RESULTS: Micrometastases were observed in 81 lymph nodes(6.5%) of 31 patients (29.5%). The incidence of lymph node micrometastases was significantly higher in the diffuse type(22 of 53 cases, 41.5%) than in the intestinal type of gastric carcinoma (9 of 51 cases, 17.6%, P < 0.01). The presence of micrometastases was closely correlated with the size and invasion depth of primary tumor, but was not correlated with age, sex and location of the primary tumor. The 5-year survival rate after surgery was 61.3% and 82.4%, respectively in patients with and without micrometastases (P = 0.0116). When the number of lymph node with micrometastases was > or = 3, the 5-year survival rate significantly decreased. CONCLUSION: The detection of lymph node micrometastases is necessary to more accurately determine the clinical staging and prognosis of patients with node-negative gastric carcinoma by routine histologic examination.