Differences in genetic instability and cellular phenotype among Barrett's, cardiac, and gastric intestinal metaplasia in a Japanese population with Helicobacter pylori.

Intestinal metaplasia is considered to be a precursor lesion in both Barrett's and intestinal-type gastric cancer. The aim was to clarify the differences in molecular pathology between specialized intestinal metaplasia (SIM) in Barrett's oesophagus (BO), cardiac (CIM) and gastric intestinal metaplasia (GIM). Eighty-eight SIM cases with BO, 30 CIM cases and 52 GIM cases in patients with or without Helicobacter pylori infectionwere analysed for genetic instability and Das-1. Microsatellite instability and a loss of heterozygosity were evaluated at five microsatellite loci. The incidence of genetic instability was 55.7% in SIM, 40.0% in CIM and 23.1% in GIM, revealing a significant difference between SIM and GIM (P < 0.0005). For each microsatellite marker analysed, there were obvious differences in frequency among the three conditions. Das-1 reactivity was significantly higher in SIM than in CIM or GIM (P < 0.0001, both). Interestingly, both genetic instability and Das-1 reactivity in SIM showed a significantly higher incidence in patients with H. pylori infection than in those without (P < 0.005 and P < 0.01, respectively). SIM is distinct from CIM and GIM, and the pathogenesis of SIM, like that of GIM, is associated to some degree with H. pylori infection in a Japanese population.