The gastric mucosa in gastric cancer patients in a low-incidence area

Abstract

Background and aims: Atrophic gastritis, intestinal metaplasia, and pyloric metaplasia are frequent precursors of noncardial intestinal-type gastric adenocarcinoma in populations in which both gastric cancer and Helicobacter pylori infection are common. We hypothesized that such lesions would be less prevalent in European gastric cancer patients.

Methods: Slides from patients who underwent gastrectomy for adenocarcinoma between 1997 and 2004 were reviewed. Tumors were categorized as intestinal or diffuse; non-neoplastic mucosa was evaluated for gastritis, atrophy, intestinal metaplasia and pyloric metaplasia.

Results: We studied 81 patients: 48 Swiss (mean age 68.5 years); 17 Italians (mean age 67.8 years); and 16 Iberians (mean age 54.8 years; P<0.001). Twelve tumors were proximal (all intestinal type), 12 in the corpus (six intestinal-type), and 57 antral (30 intestinal type). Patients with diffuse cancers were younger than those with intestinal type (P<0.05). Nineteen patients (23.4%) had a normal stomach; 30% of T1 tumors and 90% of T4s arose in a normal stomach (P<0.02). H. pylori gastritis was found in 47 patients (58%); they did not differ in age, sex, national origin, cancer location or type from those without gastritis. Intestinal metaplasia correlated with H. pylori gastritis (P=0.002). Pyloric metaplasia was infrequent and limited to rare microfoci.

Conclusions: A quarter of the patients had a normal stomach, and pyloric metaplasia was distinctly uncommon. Approaches to prevention and early detection of gastric cancer based on bioptic or serological demonstration of atrophy and metaplasia could overlook at least 25% of the people at risk in certain populations and may need to be adapted to local conditions.