Malignant transformation of Barrett's esophagus is characterized by three
distinct premalignant stages: intestinal metaplasia (MET), low- (LGD), and
high-grade dysplasia (HGD). We reported recently an increase in the
frequency of loss of 7q33-q35 between LGD and HGD as determined by
comparative genomic hybridization (P. H. J. Riegman et al., Cancer Res.,
61: 3164-3170, 2001). Now the 7q32.3-q36.1 region was additionally
characterized by allelotype analysis with 11 polymorphic markers in 15
METs, 20 LGDs, 20 HGDs, and 20 Barrett's adenocarcinomas from different
patients. Low percentages of imbalance were determined in METs and LGDs,
7% and 10%, respectively, whereas HGDs and Barrett's adenocarcinomas
revealed high percentages of loss, 75% and 65%, respectively. This
difference in frequency between LGDs and HGDs appeared highly significant:
P = 0.00007. The majority of imbalances were found at D7S2439 and D7S483,
located on 7q36.1. These data suggest that markers from this area can be
used as a diagnostic tool in Barrett's esophagus, i.e., to distinguish
between watchful waiting and active treatment