Background: Despite recent improvements in the diagnostic accuracy and techniques for identifying early gastric carcinoma, gastric carcinoma remains a major cause of death in the world.
Methods: The clinicopathologic features of 2846 surgically resected early gastric carcinomas from 1962-1987 were reviewed, and the time trends of a variety of clinicopathologic factors were studied using both an univariate and a multivariate analysis.
Results: The differentiated type of carcinoma increased in frequency from 34-50%. The percentage of patients older than 60 years of age increased from 32-56%. The number of lesions measuring less than 3 cm increased from 28-56%. The frequency of shallow-type-IIc carcinomas measuring less than 3 cm, which had been previously difficult to detect and were mainly composed of differentiated carcinomas, increased from 46-69%. The relative proportion of the differentiated type of carcinoma was significantly higher in patients older than 60 years of age than in those younger than 60. The relative proportion of differentiated-type carcinomas measuring less than 3 cm, which had been easy to detect as opposed to undifferentiated-type carcinomas, significantly increased from 56-76%.
Conclusions: The above time trends may indeed reflect genuine change. However, the recent increase in the rate of differentiated-type, small-sized carcinomas also suggests the possibility that such results may, in fact, be due mainly to improvements in both diagnostic accuracy and medical technology. Thus, a large number of undifferentiated-type, small-sized carcinomas might have merely failed to be found in routine gastric examination.