EVALUATION OF A NEW STAGING SYSTEM BY THE JAPANESE-RESEARCH-SOCIETY-FOR-GASTRIC-CANCER

The feasibility of the new classification of stage grouping by the Jap anese Research Society for Gastric Cancer was evaluated. During the 22 -year period between January 1975 and December 1996, a total of 1294 p atients with primary gastric cancer underwent laparotomy at the Depart ment of Surgery, Chiba University; 1222 had their lesions removed duri ng the gastrectomy and 72 remained nonresected, Cases of direct operat ive death totaled 17 (1.3%), Five hundred patients (38.6%) died of a r elapse of the original cancer and 42 (3.2%) died of other diseases wit hin the followup period, Six patients (0.5%) were lost during the foll owup, The 5-year cumulative patient survival rates of the seven stages of the new stage grouping were distinctly proportional, and the diffe rences were also statistically significant except between stages IIIb and IVa. The two major revised points in the new stage grouping, new c lassification of the depth of cancer invasion, and new stage grouping by a mosaic combination of the degree of invasion and lymph node metas tasis were thus found to be reasonable based on the actuarial 5-year s urvival rates of the subgroups in the same stage. The present study al so showed that the classification of stage IV still requires further d iscussion.