Losses of heterozygosity on chromosomes 9p and 17p are frequent events in Barrett's metaplasia not associated with dysplasia or adenocarcinoma

OBJECTIVE: Losses of heterozygosity (LOH) on chromosomes 9p and 17p frequently accompany malignant transformation of Barrett's esophagus (BE). They have been reported in adenocarcinoma, dysplasia, and adjacent metaplasia of patients with long-segment BE (LSBE). This study aimed to evaluate and compare the frequency of LOH on 9p and 17p in patients with long- and short-segment BE (SSBE) without dysplasia or adenocarcinoma. METHODS: Matched metaplasia and blood DNA were evaluated for LOH on chromosomes 9p and 17p in patients with a previous diagnosis of BE and no dysplasia or cancer. RESULTS: We included 18 patients (12 long-segment BE and six short-segment BE). The overall prevalence of LOH was 61% (10 of 18), with no significant difference between LSBE (58%) and SSBE (50%). The frequencies of LOH on 9p and 17p were similar (35% and 39%, respectively), with 18% of the patients showing losses at both chromosomes. CONCLUSIONS: LOH on 9p and 17p are highly frequent events in BE, even in the absence of dysplasia and adenocarcinoma. The presence of these abnormalities in non-neoplastic epithelium suggests they might be useful markers for risk stratification within endoscopic surveillance programs.