Gastric endocrine cells and gastritis in patients receiving long-term omeprazole treatment.

Both argyrophil endocrine cells and gastritis were investigated in 2,120 biopsies of gastric corpus mucosa from 443 out of 448 patients receiving long-term (for periods ranging from several months to 4 years) omeprazole treatment. None of the patients showed neoplasia or dysplasia, either endocrine or non-endocrine. In 123 out of 443 patients (27.8%), endocrine hyperplasia of diffuse (9.3%), linear (4.1%) or micronodular (14.4%) type was detected either before or at some time during treatment. Chronic atrophic gastritis was found in 45 (10.2%) patients, 60% of whom also showed micronodular hyperplasia. In patients with chronic atrophic gastritis, micronodular hyperplasia occurred in 49% of 96 biopsies, compared with 6% of 1,083 biopsies from patients with non-atrophic chronic gastritis and 2% of 941 biopsies from patients with no evidence of gastritis. In 202 patients treated with omeprazole for at least 330 days, the incidence of micronodular hyperplasia increased from 2.5% at the first biopsy to 10.4% at the final biopsy, while the incidence of chronic atrophic gastritis increased from 1.0% to 13.0%. The present and parallel studies suggest that progression of gastritis is inherent in the natural history of acid-related diseases, while endocrine cell changes are mostly secondary to gastritis-related gland atrophy and have no tumorigenic potential.