Metastasis rates of lymph nodes and distribution in advanced gastric cancer and its clinical significance

Objective To investigate the characteristics of lymph node metastases in advanced gastric cancer and its clinical significance.Methods From April 2002 to July 2003,we studied 91 patients with advanced gastric cancer who underwent radical gastrectomy and lymphadenectomy from which specimens were obtained during surgery.Then,collection of dissected lymph node,histopathological and immunohistolngical studies were performed to detect the lymph node metastasis rates and calculation.In addition,to analyze the relationship between lymph node metastasis rates and tumor diameters,TNM classification,Borrmann analysis,tumor localization and the extent of lymph node resection.Results Among 91 patients with advanced gastric cancer,lymph node metastases were found in 63 patients (69.2% ) with a total collection of 3149 lymph nodes and an average of 34.6 lymph nodes collected per patient.Lymph node metastasis rate was lower in tumor＜3 cm than that in tumor＞3 cm.About TNM classification,lymph node metastases in advanced gastric cancer among patients in stageⅢa and stageⅣwas 100%,with the lymph node metastasis rates varying from 30.3% to 58.4%,which were significantly higher than that among patients in stageⅠandⅡ(P＜0.001).About Borrmann classification,lymph nodes metastasis in advanced gastric cancer among patients in Borrmann typeⅢ(79.6%) was higher than other Borrmann types,while in Borrmann type IV with the highest lymph node metastasis rate of 35.3% (P＜0.05).Patients undergone lymph node dissection D_3 had higher lymph node metastases among patients and higher lymph node metastasis rate (88.2%,38.0% ) than patients in the D_1 and D_2(P＜0.0S).Among 91 patients,17 patients was found with micrometastasis (18.7%) from which 183 lymph nodes was collected,but no statistically significant difference between tumor location and micrometastasis was found (P＞0.05).For tumor localization,lymph node metastases in proximal gastric cancer were more shown in station 1,2,3,5,7, 8,9,12,13 and 16,with the highest metastasis rate in station 8 (68.1%).Lymph node metastases in middle gastric cancer were more shown in station 1,3,7,12,13 and 16,with the highest metastasis rate in station 3 (47.6%).Lymph node metastases in distal gastric cancer were more shown in station 1,2,3,5,6,12,13, and 16,with the highest metastasis rate in station 16 (83.3%).Conclusion Metastasis among patients and lymph node metastasis rates are significantly correlated with the severity of gastric malignancy and they may be valuable guideline to evaluate the extension of lymph nodes dissection in gastric cancer.