Dukes's classification: a valid prognostic indicator for gastric cancer.

Dukes's classification for colorectal cancer is simple, and correlates well with survival. This study assessed whether the principles of Dukes's classification applied to gastric cancer resulted in the separation of prognostically useful groups. The cumulative survival curves determined by Dukes's, Astler-Coller's (another classification for colorectal cancer), and the Japanese classification for gastric cancer were evaluated using 476 curatively treated patients with gastric cancer. Of the three staging systems, both Dukes's and the Japanese classifications showed a step-wise relationship between the stage of the tumour and the survival of patients. The prognostic value of Dukes's classification was reinforced when Dukes's C cases were subdivided according to the number of positive nodes (1-6 v > or = 7) or the level of positive nodes (n1 v n2,n3) but not when the subdivision was made according to the depth of wall invasion. A modified Dukes's classification in which Dukes's cases are subdivided according to the number of metastatic nodes (Dukes's Ca = 1-6 nodes, Dukes's Cb > 6 nodes) could be both simply and accurately applied to gastric cancer.