ACCUMULATION OF GENETIC ABNORMALITIES DURING NEOPLASTIC PROGRESSION IN BARRETTS-ESOPHAGUS

Sex chromosome status, ploidy, and proliferation rate were evaluated i n archival material of 73 Barrett's esophagus patients (48 males and 2 5 females). Diagnosis in esophageal mucosa samples ranged from intesti nal metaplasia with no dysplasia to invasive esophageal adenocarcinoma ; also, four lymph node metastases were studied. Chromosomal and ploid y aberrations were determined by in situ hybridization with repetitive DNA probes specific for chromosomes Y, X, and 1. Proliferation index (Ki-67 protein expression) was assessed by immunohistochemistry. Proli feration rate was elevated in all stages of dysplasia and in the adeno carcinomas. Aneuploidy (hyperdiploidy) and loss of the Y chromosome co rrelated with the advancing stages toward neoplasia (P < 0.001) and re ached high prevalences (70-100%) in high-grade dysplasia and adenocarc inoma. Abnormalities of the X chromosome were not seen. These data sug gest that in Barrett's esophagus, genetic perturbations may be generat ed in relation to a high proliferation rate.