Endoscopic radiofrequency ablation (RFA) eradicates intestinal metaplasia and intraepithelial neoplasia associated with Barrett's esophagus (BE), restoring an endoscopically normal neosquamous epithelium (NSE). We evaluated the post-RFA NSE for genetic abnormalities and buried glandular mucosa. Eligible patients underwent RFA for BE containing early cancer and/or high-grade intraepithelial neoplasia with subsequent complete histological reversion to normal NSE. At baseline, the BE was sampled by brush cytology and biopsies. At least 2 months after RFA, the NSE was sampled by brush cytology, keyhole biopsies, and endoscopic resection. The untreated squamous epithelium was biopsied as a control. The baseline BE and post-RFA NSE were evaluated for immunohistochemical expression of Ki-67 and p53, and genetic abnormalities (DNA-fluorescent in situ hybridization: chromosome 1 and 9, p16 and p53). In addition, biopsy depth was compared for biopsies from the NSE and untreated squamous epithelium. The presence of buried glandular mucosa in NSE was assessed with primary and keyhole biopsy, and endoscopic resection. All pretreatment specimens from all 22 patients showed abnormalities on immunohistochemical staining and fluorescent in situ hybridization, whereas all post-RFA NSE specimens were normal. All the post-RFA biopsies from the NSE contained full epithelia, whereas 37% contained lamina propria, a finding no different from biopsies from untreated squamous epithelium (36% lamina propria). Deeper keyhole biopsies contained lamina propria in 51%. All endoscopic resection specimens contained submucosa, whereas no biopsy or endoscopic resection specimen contained buried glandular mucosa. Rigorous evaluation of the post-RFA NSE in patients who, at baseline, had BE containing early cancer high-grade intraepithelial neoplasia, showed neither persistent genetic abnormalities nor buried glandular mucosa.

The precursor metaplastic mucosal lesion that predisposes for esophageal adenocarcinoma is Barrett's esophagus. Because the signal transduction events that occur in Barrett's esophagus are poorly understood, this study aimed at generating a comprehensive description of cellular kinase activity in Barrett's esophagus, normal squamous esophagus, and gastric cardia to gain more insight into the pathogenesis of Barrett's esophagus. Peptide arrays, exhibiting 1,176 specific consensus sequences for protein kinases, were used to produce a global analysis of cellular kinase activity in biopsies of Barrett's esophagus, and results were compared with the neighboring cardia and squamous epithelia. Several differences in kinase activity using immunoblot analysis and enzyme activity assays were validated in biopsies of 27 Barrett's esophagus patients. Three unique kinome profiles are described and compared. We identified cascades of activated kinases showing that mitogen-activated protein kinase and epidermal growth factor receptor activity are both significantly altered in Barrett's esophagus compared with squamous and gastric cardia epithelia. Another novel finding is that the glycolysis pathway is significantly up-regulated in Barrett's esophagus, which is illustrated by an up-regulated pyruvate kinase activity. Here, the unique kinome profile of Barrett's esophagus is made available as a comprehensive database. Several signaling pathways are revealed as specifically expressed in Barrett's esophagus when compared with the adjacent normal epithelia. These unique findings provide novel insight in the pathogenesis of Barrett's esophagus that will ultimately help to resolve the increasing problem of Barrett's esophagus and prevention of esophageal adenocarcinoma. (Cancer Res 2006; 66(24): 11605-12)

The progression of Barrett's esophagus to esophageal adenocarcinoma is often characterized by the accumulation of genetic abnormalities. The goal was to evaluate the copy number alterations of several oncogene loci, including 7p12 [epidermal growth factor receptor (EGFR)], 8q24 (c-myc), and 20q13 in the sequence of no dysplasia–dysplasia–adenocarcinoma of Barrett's esophagus. Fluorescence in situ hybridization with DNA probes for the centromeric region of chromosome 7 and the locus-specific regions of 7p12 (EGFR), 8q24 (c-myc), and 20q13 was applied on 99 brush cytology specimens of patients with Barrett's esophagus with different stages of dysplasia or esophageal adenocarcinoma. Gains (3-4 copies) of chromosome 17, 8q24 (c-myc), and 20q.13 loci were found in the low frequencies in nondysplastic Barrett's esophagus. Their frequencies increased with the stage of dysplasia and reached a high incidence in esophageal adenocarcinoma. Amplification (>4 copies) of at least 1 of the loci was observed in 14% of high-grade dysplasia and increased to 50% in esophageal adenocarcinoma (P = 0.015). The most frequently amplified locus was c-myc (18%), followed by 20q13 (13%) and EGFR (11%) in the high-grade dysplasia/esophageal adenocarcinoma cases. High amplification levels (>10 copies) of the loci were more frequent in esophageal adenocarcinoma (72%) compared with high-grade dysplasia (20%; P = 0.049). Amplifications of the c-myc, EGFR, and 20q12 loci may serve as diagnostic markers to identify patients with Barrett's esophagus with high-grade dysplasia or esophageal adenocarcinoma. Gains of the loci might be of value as prognostic markers because they are already present in nondysplasia cases and may precede the later event of the amplification as observed in high-grade dysplasia and esophageal adenocarcinoma. (Cancer Epidemiol Biomarkers Prev 2008;17(6):1380–5)

Objective: The risk of developing adenocarcinoma in non-dysplastic Barrett's oesophagus is low and difficult to predict. Accurate tools for risk stratification are needed to increase the efficiency of surveillance. We aimed to develop a prediction model for progression using clinical variables and genetic markers. Methods: In a prospective cohort of patients with non-dysplastic Barrett's oesophagus, we evaluated six molecular markers: p16, p53, Her-2/neu, 20q, MYC and aneusomy by DNA fluorescence in situ hybridisation on brush cytology specimens. Primary study outcomes were the development of high-grade dysplasia or oesophageal adenocarcinoma. The most predictive clinical variables and markers were determined using Cox proportional-hazards models, receiver operating characteristic curves and a leave-one-out analysis. Results: A total of 428 patients participated (345 men; median age 60 years) with a cumulative follow-up of 2019 patient-years (median 45 months per patient). Of these patients, 22 progressed; nine developed high-grade dysplasia and 13 oesophageal adenocarcinoma. The clinical variables, age and circumferential Barrett's length, and the markers, p16 loss, MYC gain and aneusomy, were significantly associated with progression on univariate analysis. We defined an ‘Abnormal Marker Count’ that counted abnormalities in p16, MYC and aneusomy, which significantly improved risk prediction beyond using just age and Barrett's length. In multivariate analysis, these three factors identified a high-risk group with an 8.7-fold (95% CI 2.6 to 29.8) increased HR when compared with the low-risk group, with an area under the curve of 0.76 (95% CI 0.66 to 0.86). Conclusions: A prediction model based on age, Barrett's length and the markers p16, MYC and aneusomy determines progression risk in non-dysplastic Barrett's oesophagus.