The relationship between prognostic significance of pathological type and the degree of gastric wall invasion in gastric cancer

This study was done to define the relationship between survival time and the pathological type according to the degree of gastric wall invasion by tumor after gastrectomy for patients with gastric cancer. One thousand six hundred and nine patients were identified, 783 (48.7%) patients had the differentiated type and 826 (51.3%) patients had the undifferentiated type. Overall, the survival time of the patients with undifferentiated type tumor was statistically less than that with differentiated type tumor (p < 0.01). In the subgroups, there was, however, a reversal of the relationship between survival time and pathological type. In the patients with tumor invading only the submucosa, the survival time of the patients with differentiated type tumors was statistically less than that with undifferentiated type tumors (p < 0.01), although they were of smaller diameter (p < 0.01). Conversely, in the patients with tumor invading neighboring structures, the survival time of the patients with undifferentiated type tumor was statistically less than that with differentiated type tumor (p < 0.01). When invasion of cancer cells is slight or severe, pathological differentiation is a significant prognostic factor in patients with gastric cancer.