抄録
Reported differences in clinicopathological patterns of gastric carcinoma between the West and Japan suggest the presence of differences in cancer biology. The aim of the present study was to analyze clinopathological changing patterns of gastric cancer biology in a large series of patients from Japan, where mortality rates for GC are relatively high. Based on the registered data of 2569 patients diagnosed between January 1980 and December 2000, we analyzed the differences in clinicopathological patterns for two consecutive periods: 1980-1990 (A group) and 1991-2000 (B group). Patient age ranged from 21-92 years (median: 61 years), with 70.9% of the study participants being men. Analysis revealed that there were no significant differences in the conditions of lymph node metastasis, and also no significant differences in the frequencies of tumor depth, gender, and double cancer between A and B groups. With regard to differences in age (less than 49 years vs. 50 years and over), there was a significant increase in the incidence of cancer in the patients 50 years and over. The pattern of tumor location of the lower third of the stomach increased over the period of the study, while that of the upper third of the stomach decreased. With regard to histological type, there was a significant increase in the incidence of a moderately differentiated type of tubular adenocarcinoma and poorly differentiated adenocarcinoma (por), but a significant decrease in that of signet ring cell carcinoma. Taking every factor into consideration, the incidence of early-localized cancers appears to have increased and that of advanced invasive cancers appears to have decreased in Japan during the past 20 years.
In conclusion, adenocarcinomas of the stomach with intestinal types, which related with the HP infection, decreased and those of diffuse types, which did not relate with the HP infection increased during the past 20 years.
