Histological and molecular mapping of adenocarcinoma of the oesophagus andgastroesophageal junction: Loss of heterozygosity occurs in histologicallynormal epithelium in the oesophagus and stomach

Seventy malignant, premalignant and histologically normal biopsies from 7 o esophagogastrectomy specimens of adenocarcinomas of the lower oesophagus an d gastroesophageal junction were analysed for loss of heterozygosity (LOH) at 9 known or putative gene loci. LOH was detected in 20 of 27 (74%) malign ant biopsies, 4 of 7 (57%) biopsies of dysplasia, 2 of 12 (25%) biopsies of histologically normal oesophagus adjacent to adenocarcinoma, and in 2 of 1 4 (14%) biopsies of histologically normal stomach adjacent to adenocarcinom a. LOH at the VHL, APC, CDKN2 and DCC tumour suppressor and MSH3 mismatch r epair gene loci can be detected in histologically normal tissue and in adja cent adenocarcinoma, and are potential markers of early neoplastic progress ion.