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

To study micrometastasis in lymph nodes from patients with node-negative gastric carcinoma according to routine histologic examination and its relevance to prognosis.

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.

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.

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.