BACKGROUND/AIMS: Lymph node dissection has been carried out for two decades in Japan, resulting in improved survival of patients with gastric cancer. By analyzing dissected nodes of resected advanced gastric cancers, we intend to determine which parameter(s) are more concerned in node metastasis. PATIENTS AND METHODS: Curative gastrectomy with dissection of lymph nodes was performed for 78 of the 108 patients with advanced gastric cancer. Metastases were found in 171 of 1359 nodes (13%) dissected. In each node, the maximum and minimum diameters were measured, and the ratio of the former to the latter was calculated. RESULTS: The minimum diameter of node was closely related to node metastasis. When the minimum diameter in node metastatic criteria was "3 mm or more", a sensitivity of 81% and specificity of 54% were calculated. In false negative node, signet-ring cell carcinoma (SIG) (33%) and poorly differentiated adenocarcinoma (POR) (22%) were more frequently found as primary lesions. Half or more of these nodes were invaded by only a few carcinoma cells. When the primary lesion is histologically SIG or POR, endoscopic treatment is contraindicated for possible nodes metastasis. CONCLUSIONS: It is impossible to distinguish nodes with micrometastasis from nodes without metastasis. The minimum diameter of node is more important in node metastasis of gastric cancer than the maximum diameter of node or the ratio of both.
BACKGROUND/AIMS: Lymph node dissection has been carried out for two decades in Japan, resulting in improved survival of patients with gastric cancer. By analyzing dissected nodes of resected advanced gastric cancers, we intend to determine which parameter(s) are more concerned in node metastasis. PATIENTS AND METHODS: Curative gastrectomy with dissection of lymph nodes was performed for 78 of the 108 patients with advanced gastric cancer. Metastases were found in 171 of 1359 nodes (13%) dissected. In each node, the maximum and minimum diameters were measured, and the ratio of the former to the latter was calculated. RESULTS: The minimum diameter of node was closely related to node metastasis. When the minimum diameter in node metastatic criteria was "3 mm or more", a sensitivity of 81% and specificity of 54% were calculated. In false negative node, signet-ring cell carcinoma (SIG) (33%) and poorly differentiated adenocarcinoma (POR) (22%) were more frequently found as primary lesions. Half or more of these nodes were invaded by only a few carcinoma cells. When the primary lesion is histologically SIG or POR, endoscopic treatment is contraindicated for possible nodes metastasis. CONCLUSIONS: It is impossible to distinguish nodes with micrometastasis from nodes without metastasis. The minimum diameter of node is more important in node metastasis of gastric cancer than the maximum diameter of node or the ratio of both.