Abstract
BACKGROUND: Helicobacter pylori-associated gastritis has been linked to the pathogenesis of gastric adenocarcinoma (GA), especially when associated with intestinal metaplasia (IM) and atypia/dysplasia (A/D). We examined p53 expression, ploidy and proliferative activity and assessed H. pylori infection in relationship to IM and/or A/D in cases of gastritis not associated with GA and in cases of GA. METHODS: We examined 53 gastric biopsies from patients with gastritis not associated with GA, including patients with gastritis not associated with IM and/or A/D (n=35) and with gastritis associated with IM and/or A/D (n=21). Thirty-six distal gastrectomy specimens from patients with GA constituted a third group of patients. A scoring system that encompassed the presence or absence of H. pylori, degree of gastritis, IM and/or A/D, p53, MIB-1 proliferative index (MPI) and ploidy was estimated in the cases of gastritis and in cancer-associated mucosa (CAM) and the adenocarcinoma from patients with GA. RESULTS: Patients with GA had a higher median age than those with gastritis without IM and more were males (ratio, 2.2:1). H. pylori was detected in 75% (40/53) of gastritis specimens and in 55% (20/36) of GA cases. There was a statistically significant difference between the incidence of gastritis without IM and/or A/D and CAM (P=0.01). p53 expression was seen in 67% of cases (14/21) of gastritis with IM and/or A/D and in only 5% (2 cases) of gastritis without IM (P=0.0005). A statistically significant difference in MPI was seen between CAM and GA (P=0.01) and gastritis without IM and/or A/D and gastritis with IM (P=0.004). Cases of gastritis without IM and/or A/D had a median score of 8 while cases of gastritis with IM and/or A/D had a median score of 12 (P=0.0003). CAM had a median score of 13, which was significantly different than gastritis without IM and/or A/D (P=0.0003). CONCLUSIONS: The presence of IM and/or A/D can be used in H. pylori-associated gastritis as a starting point to further investigate high-risk lesions. Those showing p53 expression, high proliferative activity and aneuploidy require closer follow up and perhaps additional biopsies. Although aneuploidy is commonly seen in GA, its presence in cases of gastritis as an isolated finding should not indicate a high-risk lesion.