Epidemiological trends of pre-malignant gastric lesions: a long-term nationwide study in the Netherlands

Background: The pre-malignant gastric lesions atrophic gastritis (AG), intestinal metaplasia (IM) and dysplasia (DYS) have long been identified as principal risk factors for gastric cancer. Objective: To evaluate epidemiological time trends of pre-malignant gastric lesions in the Netherlands. Methods: Patients with a first diagnosis of AG, IM or DYS between 1991 and 2005 were identified in the Dutch nationwide histopathology registry. The number of new diagnoses per year were evaluated relative to the total number of patients with a first gastric biopsy. Time trends were evaluated with age-period-cohort models using logistic regression analysis. Results: In total, 23 278 patients were newly diagnosed with AG, 65 937 patients with IM, and 8517 patients with DYS. The incidence of AG declined similarly in men and women with 8.2% per year [95% CI 7.9% to 8.6%], and DYS with 8.1% per year [ 95% CI 7.5% to 8.6%]. The proportional number of new IM cases declined with 2.9% per year [ 95% CI 2.7% to 3.1%] in men and 2.4% [ 95% CI 2.2% to 2.6%] in women. With age-period-cohort models a cohort phenomenon was demonstrated for all categories of pre-malignant gastric lesions in men and in women with IM and DYS. Period phenomena with a larger decline in number of diagnoses after 1996 were also demonstrated for AG and IM. Conclusions: The incidence of pre-malignant gastric lesions is declining. Period and cohort phenomena were demonstrated for diagnoses of AG and IM. These findings imply that a further decrease of at least 24% in the incidence of gastric cancer in the coming decade may be anticipated in Western countries without specific intervention.