Intestinal type: diffuse type ratio of gastric carcinoma in a Mexican population.

: This study was performed in order to define the histological patterns of gastric carcinoma according to Lauren's classification and the IT:DT ratio in a Mexican population. We analyzed the relative frequency of intestinal-type and diffuse-type carcinomas in a group of patients, diagnosed at the Instituto Nacional de Cancerologia in Mexico City between 1982 and 1992. Of the 460 cases of gastric cancer, 242 (52.7%) were of the intestinal-type, 206 (44.7%) of the diffuse type, and 12 (2.6%) others. A predominance of the diffuse type among the younger age groups (< 50 years) was observed-the transitional age for men and women occurred in the sixth decade. The global intestinal: diffuse ratio was 1.2 and increased with age. This ratio remained similar during the 11 years of the analysis. Men had a higher proportion of intestinal type carcinoma than women. These findings indicate that Mexico is not a low risk area for gastric cancer with a consistently low intestinal: diffuse type ratio. Despite differences in geographic and demographic patterns, the intestinal and diffuse types of gastric carcinoma have common etiological factors.