Barrett's esophagus-is it bad for your health?

Predictable Marker for Regression of Barrett's Esophagus by Proton Pump Inhibitor Treatment in Korea

Background/Aims

There has been no report regarding the regression of Barrett's esophagus (BE) by continuous treatment of proton pump inhibitor (PPI). The aim of this study was to determine the regression rate of BE by PPI and predictable markers related to regression.

Methods

Thirty-five patients diagnosed as BE were consecutively enrolled and most of them took continuous PPI. The 25 patients underwent endoscopic surveillance and received biopsy. If the specialized intestinal metaplasia (SIM) was lost at any point of surveillance and did not recur, the case was regarded as the regression group. The proportion of SIM was graded and the mucin phenotype was decided using immunohistochemistry for MUC2, MUC5AC and MUC6. To assess the cell proliferation indexes and the degree of intestinal maturation, immunohistochemistry for Ki67 and CDX2 were performed.

Results

The regression of BE occurred in the 11 (44%) patients. The clinical and demographic factors showed no difference between the regression (n = 11) and persistence group (n = 14). The lower grade of SIM (P < 0.001) and gastric predominant mucin phenotype (P = 0.018) were more frequent, and the number of Ki67 positive cell per gland (P = 0.008) and the mean extent of CDX2 (P = 0.022) were lower in the regression group than in the persistence group.

Conclusions

The regression of BE by PPI treatment was frequent in Korea. The immunohistochemical detection of mucin phenotype, grade of SIM, Ki67 and CDX2 expression in Barrett's mucosa could be useful as a predictable marker for regression of SIM in BE.

Evaluation of Barrett's esophagus with CK7, CK20, p53, Ki67, and COX2 expressions using chromoendoscopical examination

Barrett's esophagus (BE) is a complication of chronic gastroesophageal reflux disease and can be diagnosed when there is an endoscopically irregular Z-line and intestinal metaplasia (IM) in a biopsy obtained lower esophagus. It is still not clear whether IM in the gastric cardia or columnar mucosa without IM in the lower esophagus have any significance as BE, which is considered as preneoplastic. The aim of the study was to determine the immunohistochemical features of BE and columnar mucosa in the distal esophagus and also to evaluate the value of chromoendoscopy in the diagnosis of BE in a prospective manner. A total of 12 chromoendoscopic biopsies (six from normal-looking unstained esophagus and six from esophageal mucosa stained with methyl blue suspicious of BE) were taken from 111 cases who underwent endoscopy because of a variety of upper gastrointestinal symptoms. Immunohistochemical analysis was performed using CK7, CK20, p53, Ki67, and cyclooxygenase 2 (COX2). Of the 111 cases, 19 cases with carcinoma (nine adeno, six squamous, four undifferentiated carcinomas) and 17 cases with normal squamous epithelium were excluded, while 75 cases showing columnar epithelium, including 46 (61.3%) with IM and 29 (38,7%) without IM, were further evaluated immunohistochemically. CK7 was observed in surface, crypt, and glandular epithelium, whereas CK20 was expressed in surface and superficial crypt epithelium. No significant difference was observed between the Barrett and non-Barrett type of CK7/20 staining pattern (P > 0,05). Expression of p53 did not show any difference between BE and columnar mucosa without IM, whereas COX2 expression was significantly increased in BE (P < 0.05) in comparison with columnar mucosa without IM. Ki67 expression was significiantly higher both in upper and lower crypts in BE (P < 0.05). The present study showed that a Barrett pattern does not seem to exist; however, the analysis of COX2 expression and the Ki67 proliferation fraction by immunohistochemistry can be used to separate BE from non-Barrett's metaplasia of the distal esophagus. In our point of view, the immunohistochemical detection of p53 expression in Barrett's metaplasia stage is useless as a marker for early detection of high-risk patients.

Expression, localization and polymorphisms of the nuclear receptor PXR in Barrett's esophagus and esophageal adenocarcinoma

BACKGROUND

The continuous exposure of esophageal epithelium to refluxate may induce ectopic expression of bile-responsive genes and contribute to the development of Barrett's esophagus (BE) and esophageal adenocarcinoma. In normal physiology of the gut and liver, the nuclear receptor Pregnane × Receptor (PXR) is an important factor in the detoxification of xenobiotics and bile acid homeostasis. This study aimed to investigate the expression and genetic variation of PXR in reflux esophagitis (RE), Barrett's esophagus (BE) and esophageal adenocarcinoma.

METHODS

PXR mRNA levels and protein expression were determined in biopsies from patients with adenocarcinoma, BE, or RE, and healthy controls. Esophageal cell lines were stimulated with lithocholic acid and rifampicin. PXR polymorphisms 25385C/T, 7635A/G, and 8055C/T were genotyped in 249 BE patients, 233 RE patients, and 201 controls matched for age and gender.

RESULTS

PXR mRNA levels were significantly higher in adenocarcinoma tissue and columnar Barrett's epithelium, compared to squamous epithelium of these BE patients (P<0.001), and RE patients (P=0.003). Immunohistochemical staining of PXR showed predominantly cytoplasmic expression in BE tissue, whereas nuclear expression was found in adenocarcinoma tissue. In cell lines, stimulation with lithocholic acid did not increase PXR mRNA levels, but did induce nuclear translocation of PXR protein. Genotyping of the PXR 7635A/G polymorphism revealed that the G allele was significantly more prevalent in BE than in RE or controls (P=0.037).

CONCLUSIONS

PXR expresses in BE and adenocarcinoma tissue, and showed nuclear localization in adenocarcinoma tissue. Upon stimulation with lithocholic acid, PXR translocates to the nuclei of OE19 adenocarcinoma cells. Together with the observed association of a PXR polymorphism and BE, this data implies that PXR may have a function in prediction and treatment of esophageal disease.

Differential expression of the nuclear receptors farnesoid X receptor (FXR) and pregnane X receptor (PXR) for grading dysplasia in patients with Barrett's oesophagus

AIMS

To investigate expression of nuclear receptors farnesoid X receptor (FXR) and pregnane X receptor (PXR) as a diagnostic tool to improve grading of dysplasia in Barrett's oesophagus patients.

METHODS AND RESULTS

Immunostaining was analysed on a total of 192 biopsy samples of 22 Barrett's patients with no dysplasia (ND), 17 with low-grade dysplasia (LGD), 20 high-grade dysplasia (HGD) and 24 with adenocarcinoma (AC). Nuclear FXR expression was observed in 15 of 22 (68%) ND cases versus none of 19 HGD; 3 of 17 (18%); LGD; 5 of 60 (8%) patients with AC (P<0.001). FXR expression was highly specific for non-dysplastic tissue. Nuclear PXR was expressed in 16 of 20 (80%) HGD cases versus two of 16 (13%) LGD cases (PPV 89%). Upon examining adjacent tissue taken from HGD and AC patients, PXR expression was high in samples of all tissue types.

CONCLUSIONS

Nuclear receptors are expressed differentially during neoplastic progression, with FXR positivity being useful to distinguish ND from dysplasia and AC. PXR nuclear expression is able to separate HGD from LGD and ND. The combination of FXR and PXR also appears to have diagnostic and possibly prognostic value, but future prospective studies are required to investigate their predictive power for neoplastic progression in Barret's oesophagus.

Grading of dysplasia in Barrett's oesophagus: substantial interobserver variation between general and gastrointestinal pathologists

AIMS

To determine interobserver variation in grading of dysplasia in Barrett's oesophagus (BO) between non-expert general pathologists and expert gastrointestinal pathologists on the one hand and between expert pathologists on the other hand.

METHODS AND RESULTS

In this prospective multicentre study, non-expert and expert pathologists graded biopsy specimens of 920 patients with endoscopic BO, which were blindly reviewed by one member of a panel of expert pathologists (panel experts) and by a second panel expert in case of disagreement on dysplasia grade. Agreement between two of three pathologists was established as the final diagnosis. Analysis was performed by kappa statistics. Due to absence of intestinal metaplasia, 127/920 (14%) patients were excluded. The interobserver agreement for dysplasia [no dysplasia (ND) versus indefinite for dysplasia/low-grade dysplasia (IND/LGD) versus high-grade dysplasia (HGD)/adenocarcinoma (AC)] between non-experts and first panel experts and between initial experts and first panel experts was fair (kappa = 0.24 and kappa = 0.27, respectively), and substantial for differentiation of HGD/AC from ND/IND/LGD (kappa = 0.62 and kappa = 0.58, respectively).

CONCLUSIONS

There was considerable interobserver variability in the interpretation of ND or IND/LGD in BO between non-experts and experts, but also between expert pathologists. This suggests that less subjective markers are needed to determine the risk of developing AC in BO.

Long-term survival following endoscopic and surgical treatment of high-grade dysplasia in Barrett's esophagus

BACKGROUND & AIMS

Photodynamic therapy (PDT) for high-grade dysplasia (HGD) in Barrett's esophagus is a Food and Drug Administration-approved alternative to esophagectomy. Critical information regarding overall survival of patients followed up long-term after these therapies is lacking. Our aim was to compare the long-term survival of patients treated with PDT with patients treated with esophagectomy.

METHODS

We reviewed records of patients with HGD seen at our institution between 1994 and 2004. PDT was performed 48 hours following the intravenous administration of a photosensitizer using light at 630 nm. Esophagectomy was performed by either transhiatal or transthoracic approaches by experienced surgeons. We excluded all patients with evidence of cancer on biopsy specimens. Vital status and death date information was queried using an institutionally approved Internet research and location service. Statistical analysis was performed using Kaplan-Meier curves and Cox proportional hazards ratios.

RESULTS

A total of 199 patients were identified. A total of 129 patients (65%) were treated with PDT and 70 (35%) with esophagectomy. Overall mortality in the PDT group was 9% (11/129) and in the surgery group was 8.5% (6/70) over a median follow-up period of 59 +/- 2.7 months for the PDT group and 61 +/- 5.8 months for the surgery group. Overall survival was similar between the 2 groups (Wilcoxon test = 0.0924; P = .76). Treatment modality was not a significant predictor of mortality on multivariate analysis.

CONCLUSIONS

Overall mortality and long-term survival in patients with HGD treated with PDT appears to be comparable to that of patients treated with esophagectomy.