Microsatellite analysis provides evidence of neoplastic transformation in long-segment, but not in short-segment,...

It has been suggested that the high prevalence of short segments of specialised intestinal metaplasia (SIM) at the gastro-oesophageal junction is associated with the rising incidence of oesophageal adenocarcinoma. Our aims were to document the prevalence of short segments of SIM at the gastro-oesophageal junction in patients attending for routine endoscopy and to determine if there was molecular evidence of neoplastic transformation in those with SIM. Patients (n = 101) were recruited from randomly selected upper gastro-intestinal endoscopy lists. Biopsy specimens were taken at the squamo-columnar junction to assess the prevalence of SIM. Frozen sections were assessed for molecular evidence of neoplastic transformation using microsatellite analysis. Squamo-columnar biopsies were suitable for analysis in 95 patients, of whom 20 (21%) had oesophagitis and 2 (2%) had Barrett's oesophagus (>3 cm of endoscopically apparent columnar-lined oesophagus). Twenty patients had SIM at the gastro-oesophageal junction, including 2 with Barrett's oesophagus and 18 with short segments of SIM, one of whom had an associated intramucosal adenocarcinoma detected incidentally by histology. Three of the 20 cases with SIM exhibited novel microsatellite alleles, 2 with Barrett's oesophagus and 1 with short segment SIM and an associated adenocarcinoma. The 18 patients with short segments of SIM at the gastro-oesophageal junction were significantly older than those without SIM.