Micrometastasis detection of lymph nodes and clinical significance of lymph nodes metastasis inside the hepatoduodenal ligament in gastric cancer patients

Objective To detect lymph node micrometastasis,and to evaluate metastasis of lymph nodes inside the hepatoduodenal ligament(No.12 group) and its clinical importance,in order to guide lymphadenectomy in radical resection for gastric cancer.Methods Clinical data of 251 gastric cancer patients undergoing D2+ radical resection with No.12 lymph nodes dissection were analyzed retrospectively.Immunohistochemical staining with anti-cytokeratin 20 monoclonal antibody was used to detect micrometastasis of No.12 negative nodes confirmed by routine pathological examination.Metastasis of No.12 lymph nodes and its relationship with clinicopathological parameters were analyzed.Results The detection rate of No.12 lymph node micrometastasis was 5.71%(12/210).The metastasis rate of No.12 group increased from 16.30 to 21.11%.No.12 lymph node metastasis was significantly correlated with tumor infiltration depth,tumor size,TNM stage and metastasis of other lymph node groups(P0.01).The metastasis rates of lymph nodes around the hepatic artery(No.12a) and around the common bile duct(No.12b) were 17.93% and 11.16% respectively.No.12a metastasis was significantly correlated with No.12b metastasis(P0.05).TNM stage and No.12 lymph node metastasis were independent prognostic factors.Conclusions Immunohistochemical staining using anticytokeratin 20 monoclonal antibody is more sensitive than routine pathology for detecting micrometastasis of lymph nodes.No.12 lymph nodes metastasis adversely affects the prognosis.Lymphadenectomy of No.12 group should be performed routinely in radical resection for advanced gastric cancer,especially dissection of No.12a and No.12b with vascularization/skeletonization.