[Problems of international standardization of gastric cancer surgery]

Treatment results of gastric cancer patients differ considerably between Japan and the West, even at the same stage of disease. This may be partly explained by the varying extent of local control and the "stage-migration" theory. There is an important conceptual difference concerning lymphadenopathy and lymphadenectomy: Japanese surgeons believe that lymph nodes are the governors of metastatic disease and thus that lymphadenectomy will result in cure, while in the West lymph nodes are seen merely as the indicators of systemic metastasis and thus lymphadenectomy serves only for staging. The UICC TNM system has recently abandoned the anatomical N-classification and adopted the numeric N-classification. Although this is a good prognostic indicator, it does not provide surgeons with any information for surgical decision-making. Japanese surgeons will continue to use the Japanese classification that has served as a guideline for standard D2 lymphadenectomy. To establish an international standard for gastric cancer treatment, both sides should make efforts to understand each other and discuss most practical and beneficial treatment modalities for patients in the respective medical environments.