Background: The purpose of this study was to clarify the outcome of the ratio of the metastatic lymph nodes (RML) in gastric cancer patients.
Methods: The postoperative survival of 650 patients with gastric cancer who underwent D2 curative gastrectomy was analyzed with regard to the RML. The location, number, and RML in the N1 station and in all (N1 and N2) stations were analyzed. These data were compared from the viewpoints of staging accuracy and patient survival.
Results: The RML was classified as follows: RML 0, no involvement; RML 1, 0 to.1; RML 2,.1 to.25; and RML 3, >or=.25. The 5-year survival rates stratified by RML were RML 0, 86%; RML 1, 68%; RML 2, 35%; and RML 3, 16%. Cox model identified all methods of classifying lymph node metastases as independent prognostic indicators in each calculation. However, a second Cox regression revealed that RML was the only independent prognostic factor among the three methods (P <.001). Stage migration was present in 35 cases (15%) when the number was considered. However, only 15 cases (7%) were underdiagnosed when RML was used.
Conclusions: RML is a useful classification of patients with gastric cancer. It may prevent the phenomenon of stage migration.