COMPARISON OF SURVIVAL CURVES OF GASTRIC-CANCER PATIENTS AFTER SURGERY ACCORDING TO THE UICC STAGE CLASSIFICATION AND THE GENERAL RULES FOR GASTRIC-CANCER STUDY BY THE JAPANESE-RESEARCH-SOCIETY-FOR-GASTRIC-CANCER

Objective This study compared the UICC classification with the General Rules for Gastric Cancer Study (GRGCS) of the Japanese Research Society by analyzing recent results of gastric cancer surgery in Japan. Summary Background Data The present UICC stage classification for gastric cancer was published in 1987 and the Japanese GRGCS were published in 1985. Both are based on the results of surveys conducted in the early 1970s. Methods The survival curves of 926 patients, who underwent gastric cancer surgery between 1982 and 1985 at Kyoto University Hospital and its 31 associated hospitals, were analyzed according to the UICC classification and the GRGCS using SAS computer software. Results There was no difference in survival rate between UICC stages IA and IB. GRGCS stage III was found to include UICC stages II, IIIA, and IIIB, and GRGCS stage IV included UICC stages IIIA, IIIB, and IV, with significantly different survival rates. In contrast, each UICC stage included different GRGCS stages with no significant differences in survival rates. The survival rate of stage IV patients of both classifications who underwent gastrectomy was significantly higher than that of stage IV patients receiving bypass or exploratory surgeries. Conclusions The UICC classification is better than the GRGCS for classifying gastric cancer in Japan. However, UICC stage I does not need to be subdivided into stages IA and IB, and stage IV should be further subdivided into stages IVA and IVB according to the surgery performed: IVA, gastrectomy, and IVB, bypass or exploratory surgery.