Low frequency of intestinal metaplasia in gastric biopsies from Mexican patients: a comparison with Japanese and Swedish patients.

A systematic analysis of the cellular and structural components of intestinal metaplasia (IM) was carried out in 691 consecutive endoscopic gastric biopsies from Mexicans patients. Two-thirds of the patients (461 or 66.7%) had chronic gastritis, 27.6% (or 191 patients) had gastric ulcers and 5.6% (39 patients) gastric carcinomas. IM was found in 17.4% of the gastric biopsies. While IM was present in 27.7% of patients with gastric peptic ulcer, patients with gastric malignancy had only 18.7%, and the lowest rate (13.4%) was found in 461 biopsies from patients with chronic gastritis. IM was influenced by the age but not by the sex of the patients. Only one of 120 biopsies with IM (0.8%) had incomplete IM (a lesion claimed to be a precursor of gastric carcinoma). In a previous study it was found that 32.3% of 359 Swedish patients and 59.2% of 625 Japanese patients with chronic gastritis had IM, the proportion of incomplete IM being 23.3% and 25.1%, respectively. The low frequency of IM among Mexicans (a population with a low incidence of gastric carcinoma), contrasts with the moderate frequency of IM among Swedes (who have a moderate gastric cancer incidence) and with the high frequency of IM among Japanese (with a high incidence of gastric carcinoma). These findings recorded in disparate geographical regions strongly support the view that IM is a lesion evoked by environmental factors and associated with gastric carcinogenesis.