[Re-discussion of lymph node metastasis from gastric cancer on prognostic evaluation]

Lymph node metastasis from gastric cancer is one of the most important events in the progress of disease, which may reflect the disease situation and contribute to evaluate accurately prognosis. Although the detailed mechanism of lymph node metastasis from gastric cancer has not been clearly elucidated, nodal metastasis comprise of a series of events involving the alterations of tumor biological characteristics, including changes of cancer cell proliferation, invasion, chemotaxis, and pathway of lymphatic drainage. As we know, assessment of lymph node metastatic status is significantly associated with both therapeutic strategy and prognostic prediction, It is controversial to adopt the optimal category of lymph node metastasis in clinical practice. Category based on the number of lymph node metastasis (e.g. N stage of UICC TNM classification) is considered as a prominent variable to apply for gastric cancer worldwide, nevertheless, category based on extent of lymph node metastasis (e.g. N stage of JGCA classification) is capable of contributing to the appropriate surgical procedure for patients. It has not reached a consensus for the assessment impacts of several special variables on prognostic evaluation in gastric cancer, including nodal micrometastasis, isolated tumor cells (ITCs) in lymph nodes, and skipping metastasis of lymph nodes, which needs further investigations to determining the application values in gastric cancer.