The diagnosis of low-grade dysplasia in Barrett's esophagus and its implications for disease progression

Endoprevention of esophageal cancer: endoscopic ablation of Barrett's metaplasia and dysplasia

This review describes the use of endoscopic therapy for the treatment of Barrett's disease and the prevention of esophageal carcinoma, predominantly a disease of older white men. While the term endoprevention may be novel, gastroenterologists have been using endoscopic techniques to prevent colon cancer for decades. For the endoprevention of Barrett's carcinoma, the regulatory approval for the use of porfimer sodium photodynamic therapy was an important milestone, as this treatment has been proven to safely ablate Barrett's glandular epithelium, including high-grade dysplasia, and significantly decrease the risk for the development of invasive cancer in several single-center studies, a prospective multicenter randomized controlled study using expert centralized histopathology analysis and long-term single-center results. Newer methods of mucosal ablation, such as the radiofrequency balloon, have been developed for the treatment of patients with Barrett's metaplasia or dysplasia. These newly developed techniques are able to treat large fields of glandular epithelium in a short treatment procedure using safe, effective, durable methods for the complete ablation of Barrett's metaplasia and low-grade dysplasia. These techniques may finally allow the interventional gastrointestinal endoscopist to prevent the development of esophageal carcinoma, just as colonoscopy with polypectomy has prevented colon cancer. However, it will be critically important to document the safety, durability and efficacy of these devices. Ultimately, the impact of successful Barrett's ablation on the incidence of Barrett's carcinoma, and the need for postablation surveillance endoscopy must be determined.

The rationale for screening and surveillance of Barrett's metaplasia

Oesophageal adenocarcinoma is a rare cancer; however, it is the most rapidly increasing cancer in the western world. Barrett's oesophagus is the only recognised precursor and is associated with the majority of cases of adenocarcinoma. The role of screening and surveillance in patients with Barrett's oesophagus remains controversial. There is insufficient evidence to show that screening improves survival and is cost-effective. Indirect evidence suggests that patients diagnosed with cancer while undergoing surveillance endoscopy are diagnosed at an earlier stage and have an improved survival. The problems with current surveillance techniques include lack of data on natural history of Barrett's oesophagus, test invasiveness, costs, lack of standardisation and validation of biopsy and treatment protocols, and endoscopy intervals. The use of novel endoscopic techniques and biomarkers combined with better identification of high-risk groups could make screening and surveillance a cost-effective practice in the future.

[Barrett's oesophagus: endoscopic diagnosis and follow-up]

Barrett's oesophagus (BO), or replacement of the squamous mucosa by a specialized intestinal metaplasia due to gastro-oesophageal reflux disease (GORD), predisposes to adenocarcinoma. It is estimated that 6 to 12% of patients undergoing GI endoscopy have short BO (< 3 cm), and 1% have a long BO. Macroscopic diagnosis of BO is sometimes difficult and, in case of doubt, endoscopy should be redone after a period of efficient anti-secretory treatment. Diagnosis of BO is histological and should be confirmed by biopsies. The incidence of adenocarcinoma is globally estimated at 0.5% patient by year of follow-up, and exists for both short and long BO. Due to this low incidence, screening for BO is only justified in patients at high risk for adenocarcinoma (male gender, age > 50 ans, old GORD in a young patient). Low-grade dysplasia (LGD) then high-grade dysplasia (HGD) precedes adenocarcinoma. Histological diagnosis of LGD is difficult: the main cause of confusion is inflammation so diagnosis of LGD must be confirmed after a 3-month high-dose anti-secretory treatment. Diagnosis of HGD is easier but multiple biopsies are needed to determine the focal or multifocal disposition of HGD. The benefit of follow-up of BO is debated. Aged patients should be followed only if dysplasia is present. When dysplasia is absent, an endoscopic control with biopsies is desirable within 3 to 5 years. In case of dysplasia, the latter must be confirmed by another examination of biopsies, particularly in case of suspicion of HGD and after antisecretory treatment. In case of LGD, endoscopy with biopsies should be redone 6 months later to screen for HGD, then every year if LGD is confirmed. In case of HGD, the 5-year risk of cancer is 60% so surgical or endoscopic treatment is usually proposed. If HGD follow-up is decided, it should be performed on a 3- to 6-month basis.

Photodynamic therapy for Barrett's esophagus with high-grade dysplasia

This article describes advances in photodynamic therapy for patients with Barrett's esophagus and high-grade dysplasia-an important, minimally invasive treatment option proven to safely and durably ablate Barrett's dysplasia and prevent carcinoma while preserving the gastroesophageal junction.

Endoscopic treatment of high-grade intraepithelial neoplasia and early cancer in Barrett oesophagus

In the last 5 years, endoscopic therapy for high-grade intraepithelial neoplasia (HGIN) and early cancer (EC) in Barrett oesophagus has emerged as an effective and safe alternative to surgery. Adequate work-up of patients includes histopathological review of the initial biopsies, a high-resolution endoscopy with four-quadrant random biopsies every 1cm of Barrett mucosa and staging with endoscopic ultrasonography. Endoscopic resection (ER) forms the mainstay of the endoscopic treatment since it provides large tissue specimens for optimal histopathological evaluation. The ER-cap technique with submucosal injection and the 'suck-band-and cut' method are the resection methods most widely used in Barrett oesophagus patients. ER monotherapy for HGIN or EC in Barrett oesophagus is associated with recurrent lesions in up to 30% of treated patients. ER may be combined with ablative techniques such as photodynamic therapy (PDT) to treat all of the mucosa at risk for neoplastic progression. Unlike ER, PDT lacks histopathological correlation and residual Barrett mucosa may remain after treatment or may be hidden underneath the neosquamous epithelium. Management of Barrett oesophagus patients with HGIN or EC should be performed in centres with multi-disciplinary experience in this field and future studies should focus on development of ER techniques that allow radical resection of the whole Barrett segment.

Barrett's surveillance is worthwhile and detects curable cancers. A prospective cohort study addressing cancer incidence, treatment outcome and survival

OBJECTIVES

To establish whether Barrett's surveillance is worthwhile in terms of incident cancers and whether outcomes are favourable.

METHODS

A prospective non-randomized single centre Barrett's surveillance programme commencing 1 January 1992 through 1 April 2001 (112 months). Oesophagectomy recommended for high-grade dysplasia or carcinoma.

RESULTS

Of 23 725 patients, 506 were diagnosed as Barrett's oesophagus and 24 (5%) had carcinoma at diagnosis (prevalence cancers). One hundred and twenty-six patients had at least one surveillance endoscopy; 248 surveillance endoscopies were performed spanning 338 patient years. Thirteen surveillance (incidence) cancers were detected. In the prevalence cancer group 12 of the 24 patients underwent oesophagectomy. Lymph nodes showed evidence of metastases in 10 of the 12 resections. In the surveillance group 10 patients underwent oesophagectomy. Lymph nodes showed evidence of metastases in one of the 10 resections. One patient in the prevalence cancer group (4% of group; 8% of those operated) and seven patients in the surveillance cancer group (54% of group; 70% of those operated) remain disease-free more than 2 years post-oesophagectomy. The cost per cancer cured is 7546 pounds. One curable cancer was detected per 48 patient years of surveillance.

CONCLUSIONS

Few Barrett's surveillance studies have addressed treatment outcomes and survival. In our study 5% of Barrett's patients undergoing endoscopy have prevalent cancers. If surveillance is performed, 4% per year develop cancer and 2% per year are cured of their cancers. Most surveillance cancers are operable and of those undergoing surgery 70% are cured. Barrett's surveillance is cost-effective compared with other cancer screening or surveillance initiatives.

The cost-effectiveness of biomarkers for predicting the development of oesophageal adenocarcinoma

BACKGROUND

The recommended surveillance strategy for oesophageal adenocarcinoma may prevent as few as 50% of cancer deaths. Tissue biomarkers have been proposed to identify high-risk patients.

AIM

To determine performance characteristics of an ideal biomarker, or panel of biomarkers, that would make its use more cost-effective than the current surveillance strategy.

METHODS

We created a Markov model using data from published literature, and performed a cost-utility analysis. The population consisted of 50-year-old Caucasian men with gastro-oesophageal reflux, who were monitored until age 80. We examined strategies of observation only, current practice (dysplasia-guided surveillance), surveillance every 3 months for patients with a positive biomarker (biomarker-guided surveillance), and oesophagectomy immediately for a positive biomarker (biomarker-guided oesophagectomy). The primary outcome was the threshold cost and performance characteristics needed for a biomarker to be more cost-effective than current practice.

RESULTS

Regardless of the cost, the biomarker needs to be at least 95% specific for biomarker-guided oesophagectomy to be cost-effective. For biomarker-guided surveillance to be cost-effective, a $100 biomarker could be 80% sensitive and specific.

CONCLUSIONS

Biomarkers predicting the development of oesophageal adenocarcinoma would need to be fairly accurate and inexpensive to be cost-effective. These results should guide the development of biomarkers for oesophageal adenocarcinoma.

What is dysplasia in the gastrointestinal tract?

Dysplasia in the gastrointestinal tract is considered both a carcinoma precursor and a marker of high cancer risk for the site at which it is found. Dysplasia is defined as unequivocally neoplastic epithelium, yet the specific criteria for making that determination are imperfectly defined. The current criteria actually include a mix of architectural and cytologic features, all of which occur in different intensities in different epithelia that are given the same diagnosis. Gastrointestinal dysplasias are divided into 2 grades, but there are problem areas in diagnosis at the lower end where low-grade dysplasias overlap with regenerating epithelia and in the middle where low- and high-grade dysplasias overlap. The diagnosis of dysplasia is too subjective with less than optimal reproducibility to be as useful a marker as needed. Pathologists need a dysplasia stain or a whole set of new markers of high cancer risk, presumably molecular and/or genetic, that are not dependent on pathologists' diagnoses of dysplasia and their inherent subjectivity.

The use of optical coherence tomography in screening and surveillance of Barrett's esophagus

Barrett's esophagus (BE) is defined as the presence of specialized intestinal metaplasia within the tubular esophagus. Recent studies suggest that performing endoscopic surveillance in patients with Barrett's esophagus is effective in preventing esophageal adenocarcinoma at an early stage. However, the accuracy of surveillance endoscopy is limited by sampling error and cost. Optical coherence tomography (OCT) is an optical analog of ultrasound, providing 10-microm resolution and real-time cross-sectional images of the luminal gastrointestinal tract. The literature describing the use of OCT in models of dysplasia and BE are reviewed. Three studies have examined the use of OCT in BE and models of dysplasia. These studies suggest that the currently achievable resolution combined with light-scattering properties of Barrett's mucosa is adequate to discern intestinal metaplasia and reliably detect high-grade dysplasia in patients with BE. Additional research to validate these findings is required.

Ki67 and p53 immunohistochemistry reduces interobserver variation in assessment of Barrett's oesophagus

AIMS

To devise clinically applicable methods for assessing p53 and Ki67 immunohistochemical (IHC) reactivity in Barrett's oesophagus (BE) and to compare the interobserver agreement between these methods and routine haematoxylin and eosin (H&E) evaluation.

METHODS AND RESULTS

One hundred and fifteen biopsies diagnosed as BE, selected from the files of the University Hospital MAS, Malmo, were re-evaluated for dysplasia by three pathologists. For IHC analysis areas with the most prominent positivity were evaluated. The mean of p53+ epithelial nuclei/high-power field (HPF) was obtained by counting between 1 and 5 HPFs/biopsy. A proliferation quotient (PQ) was obtained by dividing the number of Ki67+ epithelial nuclei in the upper half by the lower half of the mucosa, using two HPFs. Mean kappa values were 0.24, 0.71 and 0.52 for H&E, p53 and Ki67 evaluations, respectively. There was a correlation between increasing severity of dysplasia, IHC measurable overexpression of p53 and shift of the mucosal proliferation zone towards the surface, measured as PQ.

CONCLUSIONS

The described methods for p53 and Ki67 evaluation are more reproducible than routine H&E evaluation of BE. Furthermore, the IHC methods correlate with the severity of dysplasia and are useful supplementary prognostic markers.

A randomized crossover study comparing light-induced fluorescence endoscopy with standard videoendoscopy for the detection of early neoplasia in Barrett's esophagus

BACKGROUND

Light-induced fluorescence endoscopy (LIFE) may improve the detection of high-grade dysplasia (HGD) and early stage cancer (EC) in Barrett's esophagus (BE). The aim of this study was to compare LIFE with standard endoscopy (SE) in a randomized crossover study.

METHODS

Fifty patients with BE underwent SE and LIFE in a randomized sequence (4 to 6-week interval between procedures). The two procedures were performed by two different endoscopists who were blinded to the findings of the other examination. Targeted biopsy specimens were taken from detected lesions, followed by random biopsy specimens with a 2-cm interval, 4-quadrant protocol. Biopsy specimens were routinely evaluated and subsequently reviewed by a single, blinded expert GI pathologist.

RESULTS

Targeted biopsy specimens had a sensitivity for the diagnosis of HGD/EC of 62% (8/13) for both techniques. The overall sensitivity (all biopsy specimens) was 85% for SE and 69% for LIFE (p = 0.69). All targeted biopsy specimens had a positive predictive value (PPV) for HGD/EC of 41% for SE and 28% for LIFE (p = 0.40); autofluorescence-targeted biopsy specimens had a PPV of 13%. False-positive lesions had a significantly higher rate of acute inflammation than random biopsy specimens.

CONCLUSIONS

In this study, LIFE did not improve the detection of HGD or EC in patients with BE compared with SE.

Inactivation of p16, RUNX3, and HPP1 occurs early in Barrett's-associated neoplastic progression and predicts progression risk

Patients with Barrett's esophagus (BE) are at increased risk of developing esophageal adenocarcinoma (EAC). Clinical neoplastic progression risk factors, such as age and the length of the esophageal BE segment, have been identified. However, improved molecular biomarkers predicting increased progression risk are needed for improved risk assessment and stratification. Using real-time quantitative methylation-specific PCR, we screened 10 genes (HPP1, RUNX3, RIZ1, CRBP1, 3-OST-2, APC, TIMP3, p16, MGMT, p14) for promoter hypermethylation in 77 EAC, 93 BE, and 64 normal esophagus (NE) specimens. A subset of genes manifesting significant differences in methylation frequencies between BE and EAC was then analysed in 20 dysplastic specimens. All 10 genes except p14 were frequently methylated in EACs, with RUNX3, HPP1, CRBP1, RIZ1, and OST-2 representing novel methylation targets in EAC and/or BE. p16, RUNX3, and HPP1 displayed increasing methylation frequencies in BE vs EAC. Furthermore, these increases in methylation occurred early, at the interface between BE and low-grade dysplasia (LGD). To demonstrate the silencing effect of hypermethylation, we selected the EAC cells BIC1, in which the HPP1 promoter is natively methylated, and subjected them to 5-aza-2'-deoxycytidine (Aza-C) treatment. Real-time RT-PCR indicated increased HPP1 mRNA levels after 3 days of Aza-C treatment, as well as decreased levels of methylated HPP1 DNA. Hypermethylation of a subset of six genes (APC, TIMP3, CRBP1, p16, RUNX3, and HPP1) was then tested in a retrospective longitudinal study of 99 BE and nine LGD specimens obtained from 53 BE patients undergoing surveillance endoscopy. Only high-grade dysplasia (HGD) or EAC were defined as progression end points. Two patient groups were compared: eight progressors (P) and 45 nonprogressors (NP), using Cox proportional hazards models to determine the relative progression risks of age, BE segment length, and methylation events. Multivariate analyses revealed that only hypermethylation of p16 (odds ratio (OR) 1.74, 95% confidence interval (CI) 1.33-2.20), RUNX3 (OR 1.80, 95% CI 1.08-2.81), and HPP1 (OR 1.77, 95% CI 1.06-2.81) were independently associated with an increased risk of progression, whereas age, BE segment length, and hypermethylation of TIMP3, APC, or CRBP1 were not independent risk factors. In combined analyses, risk was detectable up to, but not earlier than, 2 years preceding neoplastic progression. Hypermethylation of p16, RUNX3, and HPP1 in BE or LGD may represent independent risk factors for the progression of BE to HGD or EAC. These findings have implications regarding risk stratification, early EAC detection, and the appropriate endoscopic surveillance interval for patients with BE.

Dysplasia in Barrett's esophagus: limitations of current management strategies

Dysplasia is a very imperfect biomarker for malignancy in Barrett's esophagus. Invasive cancer has been found in 30-40% of esophagi resected because preoperative endoscopic examinations had shown high-grade dysplasia. Reports on the natural history of this disorder are sometimes contradictory, but suggest that 10-30% of patients with high-grade dysplasia in Barrett's esophagus will develop a demonstrable malignancy within 5 yr of the initial diagnosis. Proposed management strategies for high-grade dysplasia include esophagectomy, endoscopic ablative therapies, endoscopic mucosal resection (EMR), and intensive endoscopic surveillance. Endoscopic ablative therapies and EMR may not be effective if neoplastic cells have invaded the submucosa or disseminated through mucosal lymphatic channels, and a number of studies suggest that the endoscopic therapies usually leave metaplastic or neoplastic epithelium with malignant potential behind. Limited data suggest that intensive endoscopic surveillance might be a reasonable approach for elderly or infirm patients, but some patients managed in this fashion have developed incurable esophageal cancers. The fundamental question of what is the appropriate length of follow-up for studies on dysplasia treatments has not been resolved. Although 5 yr might be considered the absolute minimum duration for a meaningful follow-up on dysplasia therapy, the follow-up duration in most studies is substantially less than 5 yr. Specific recommendations for management based on these considerations are proposed at the end of this report.

Dysplasia and risk of further neoplastic progression in a regional Veterans Administration Barrett's cohort

OBJECTIVES

No published data are available on the risk of further neoplastic progression in Barrett's patients stratified by baseline dysplasia status. Our aims were to estimate and compare the risk of progression to high-grade dysplasia or cancer in groups of Barrett's patients stratified by baseline dysplasia status.

METHODS

Consecutive Barrett's cases from 1988-2002 were identified via pathology databases in a regional VA health-care system and medical record data were abstracted. The risk of progression to high-grade dysplasia or cancer was measured and compared in cases with versus without low-grade dysplasia within 1 yr of index endoscopy using survival analysis.

RESULTS

A total of 575 Barrett's cases had 2,775 patient-years of follow-up. There were 13 incident cases of high-grade dysplasia and two of cancer. The crude rate of high-grade dysplasia or cancer was 1 of 78 patient-years for those with baseline dysplasia versus 1 of 278 patient-years for those without (p= 0.001). One case of high-grade dysplasia in each group underwent successful therapy. One incident cancer case underwent successful resection and the other was unresectable. Two cases with high-grade dysplasia later developed cancer, one died postoperatively, the other was unresectable. When these two cases were included (total of four cancers), the crude rate of cancer was 1 of 274 patient-years for those with baseline dysplasia versus 1 of 1,114 patient-years for those without.

CONCLUSIONS

In a large cohort study of Barrett's, incident malignancy was uncommon. The rate of progression to high-grade dysplasia or cancer was significantly higher in those with baseline low-grade dysplasia. These data may warrant reevaluation of current Barrett's surveillance strategies.

Present status of photodynamic therapy for high-grade dysplasia in Barrett's esophagus

GOALS

Review recent developments in Barrett's dysplasia including regulatory approval of porfimer sodium photodynamic therapy.

BACKGROUND

Barrett's esophagus is thought to be the result of long-standing gastroesophageal reflux disease and is known to be the most important risk factor for the development of esophageal adenocarcinoma. The natural history of Barrett's esophagus is not well known, but the annual incidence of invasive adenocarcinoma is estimated to be 0.5% (reported range, 0.2%-2.0%). This represents an increased risk for esophageal cancer of 30 to 60 times higher than normal subjects. As for colorectal cancer, malignant degeneration is Barrett's esophagus is thought to occur through a continuum of histologic stages: metaplasia, dysplasia and neoplasia. Barrett's high-grade dysplasia (formerly referred to as carcinoma in situ) is the histologic stage of disease that immediately precedes the development of invasive carcinoma.

CONCLUSIONS

Previously, Barrett's high-grade dysplasia patients were routinely referred for esophageal resection surgery based upon the assumption of inevitable progression to cancer, the high rate of undiagnosed synchronous cancers, and few treatment alternatives. Important developments in Barrett's high-grade dysplasia include recent publications regarding the natural history of Barrett's high-grade dysplasia and the regulatory approval for endoscopic ablation therapy using porfimer sodium photodynamic therapy (Photofrin PDT).

Endoscopic treatment of Barrett's oesophagus

Barrett's oesophagus develops as a consequence of severe gastro-oesophageal reflux. The importance of Barrett's oesophagus lies in the small risk of developing high-grade dysplasia and subsequent adenocarcinoma. Because of poor treatment results in patients with advanced adenocarcinoma, surveillance of patients with Barrett's oesophagus for the development of dysplasia, although not uncontroversial, is widely practised in the gastroenterological community. The aim of surveillance is to detect adenocarcinoma in an early stadium where surgical cure is possible. In recent years several endoscopic treatments for both high-grade dysplasia and intramucosal adenocarcinoma have been developed. In this review some basic aspects of Barrett's oesophagus are discussed together with endoscopic treatments such as endoscopic mucosal resection, local thermal treatments and photodynamic therapy. Although surgical resection is probably the treatment of choice in fit patients, local endoscopic treatments should be considered in patients with high-grade dysplasia or intramucosal carcinoma who are unfit or unwilling to have surgery.

Oesophageal cancer incidence and mortality in patients with long-segment Barrett's oesophagus after a mean follow-up of 12.7 years

BACKGROUND

Data on cancer risk in patients with long-segment Barrett's oesophagus (BO) from older studies are often difficult to interpret, since the definition of BO has evolved from an endoscopical to a histological diagnosis. In this work the diagnoses in the Rotterdam BO cohort on current standards was redefined to obtain more accurate data on cancer risk in patients who had not undergone standard endoscopic surveillance. In addition, it was determined which patient factors present at index endoscopy were associated with neoplastic progression in BO.

METHODS

The Rotterdam BO cohort comprises all patients with > or =3 cm BO, diagnosed at endoscopy between 1973 and 1984. In the present study, only patients with intestinal metaplasia were included (n = 105). Follow-up data were obtained by questionnaires and/or interviews with patients or treating physicians. A Kaplan-Meier analysis was used to estimate 20-year risks.

RESULTS

The mean length of the BO was 7.1 cm (range: 3-15 cm). Cancer in BO developed in 6/105 (6%) patients, and high-grade dysplasia (HGD) in 5/105 (5%) patients during 1329 patient-years of follow-up, which equals one cancer case per 221 patient-years and one HGD case per 266 patient-years. After a mean follow-up of 12.7 years, 72 (69%) patients had died; only 4 of them died of oesophageal cancer or its treatment. A longer length of BO was associated with an increased risk of progression to HGD or cancer (P < 0.02). Six of 24 patients who ever had low-grade dysplasia progressed to HGD or cancer 2-16 years after a diagnosis of BO.

CONCLUSIONS

The annual risk of developing HGD or adenocarcinoma in patients with long-segment BO is 0.83%. Death due to adenocarcinoma is, however, uncommon, even in a cohort of patients with long-segment BO.

Review article: what I do now to manage adenocarcinoma risk, and what I may be doing in 10 years' time

This article summarizes the present recommendations for the screening, surveillance and treatment of Barrett's oesophagus, and identifies those areas in which change seems likely within the next decade. As a result of economic constraints and emerging data on ethnic variations in the frequency of Barrett's oesophagus, future screening programmes will probably focus on those individuals most likely to develop Barrett's adenocarcinomas: older white men whose gastro-oesophageal reflux symptoms are of long duration. The present surveillance strategy for patients with Barrett's oesophagus relies heavily on random biopsy sampling of the oesophagus to find dysplasia. In the future, biomarkers other than dysplasia may be used to identify patients at high risk for carcinogenesis, and physicians may use endoscopic techniques, such as fluorescence spectroscopy, to identify areas of dysplasia for biopsy sampling. Indirect evidence suggests that super-aggressive antisecretory therapy and treatment with non-steroidal anti-inflammatory drugs may reduce the risk of cancer in Barrett's oesophagus. Well-designed prospective studies will be needed to determine whether these treatments have sufficient efficacy in cancer prophylaxis to justify the large numbers needed to treat. Finally, recent data are reviewed, which suggest that the gastro-oesophageal junction is exposed repeatedly to concentrated acid and to potentially genotoxic concentrations of nitric oxide generated from dietary nitrate. Future studies on carcinogenesis in Barrett's oesophagus may well focus on the combined roles of nitric oxide and gastric acid.

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Risk stratification of Barrett's esophagus: updated prospective multivariate analysis

OBJECTIVES

Prospective evaluation of Barrett's esophagus (BE) in order to determine what demographic, endoscopic, and histologic features are predictive of the prevalence and incidence of Barrett's high-grade dysplasia (HGD) and adenocarcinoma (Ca).

METHODS

Newly diagnosed BE patients were entered into and followed in a standardized surveillance protocol. The following features were examined using either forward, stepwise multiple regression analysis, or Cox proportional hazards to determine their ability to predict the presence of HGD or Ca at index BE diagnosis as well as their ability to predict progression of BE during follow-up: age, race, gender, length of BE in cm, size of a hiatal hernia, severity of dysplasia at index diagnosis as well as during surveillance, gastric Helicobacter pylori infection status, and type of medical acid-reflux treatment.

RESULTS

A total of 550 patients were diagnosed with BE over the study period. Stepwise multiple regression analysis showed three factors significantly associated with index diagnosis of HGD or Ca: hiatal hernia (larger size), Barrett's length (longer length), and absence of H. pylori infection. Three hundred and twenty-four BE entered the surveillance protocol. Cox proportional hazards models revealed a significant and independent association for five factors predictive of the time to progression of BE: presence of dysplasia at index diagnosis (p < 0.001), severity of dysplasia during surveillance (p < 0.001), length of Barrett's epithelium (p= 0.012), size of hiatal hernia (p= 0.006), and gastric H. pylori infection status (p= 0.023).

CONCLUSIONS

Endoscopic and histologic features of BE at initial diagnosis are predictive of index HGD and cancer as well as with risk of BE progression.

Fluorescence in situ hybridization of cytologic specimens from Barrett's esophagus: a pilot feasibility study

BACKGROUND

Endoscopic brush cytology is a promising surveillance technique for Barrett's esophagus. However, there is a need for ancillary biomarkers to increase the sensitivity of cytology and to allow identification of patients at increased risk for disease progression. The aims of this study were to evaluate the feasibility of fluorescence in situ hybridization of endoscopic brush cytology specimens and to determine if there are specific chromosomal changes in cytologic specimens from patients with cancer that are not present in patients without dysplasia.

METHODS

Archival cytology slides from 16 patients with Barrett's esophagus were studied: 8 negative for dysplasia and 8 positive for adenocarcinoma. Fluorescence in situ hybridization was used to detect two alterations: HER-2 gene (17q11.2-q12) and 20q13.2 region amplification.

OBSERVATIONS

For 7 of 8 adenocarcinoma cases, there was amplification/aneusomy of at least one of the two analyzed regions by fluorescence in situ hybridization. None of the samples negative for dysplasia were abnormal for either of the two genomic regions studied.

CONCLUSIONS

Fluorescence in situ hybridization is feasible by using routine Barrett's esophagus cytologic specimens. Differences in genomic makeup can be detected in cells from patients negative for dysplasia and in those with adenocarcinoma.

Displasia no esôfago de Barrett - concordância intra e interobservador no diagnóstico histopatológico

RACIONAL: O potencial maligno do esôfago de Barrett é bem reconhecido. A vigilância endoscópica e a abordagem terapêutica se baseiam na presença e graduação da displasia. Contudo, a validade do diagnóstico histopatológico pode ser questionada devido à precária reprodutibilidade tanto intra como interobservador. OBJETIVO: Avaliar a concordância intra e interobservador no diagnóstico de displasia no esôfago de Barrett. MATERIAL E MÉTODOS: O material foi constituído por 42 blocos de parafina contendo fragmentos de esôfago provenientes de biopsias endoscópicas de portadores de esôfago de Barrett. Cortes de 3 micrômetros foram corados pela hematoxilina-eosina e pelo PAS-alcian blue. A leitura das lâminas foi realizada de maneira cega, em microscópio óptico. A reprodutibilidade intra e interobservador utilizou o teste kappa. RESULTADOS: O número total de fragmentos foi de 229, com média de 5,45 (1 a 18) fragmentos por paciente. O diagnóstico de displasia de baixo grau firmado pelos diferentes patologistas variou de 21,4% a 52,4%. A concordância intra-observador para o diagnóstico de displasia de baixo grau foi fraca (kappa = 0,30). A concordância interobservador para o diagnóstico de displasia de baixo grau foi pobre, com escore kappa oscilando entre 0,05 e 0,16. O diagnóstico de displasia, firmado pela concordância entre todos os patologistas, foi de 14,3%. CONCLUSÕES: A concordância no diagnóstico histopatológico de displasia de baixo grau no esôfago de Barrett, tanto intra quanto interobservador, é ruim. Idealmente, à semelhança da displasia de alto grau, o diagnóstico de displasia de baixo grau no esôfago de Barrett também deveria ser confirmado por mais de um patologista.

Biomarkers of esophageal adenocarcinoma and Barrett's esophagus

The rising incidence and poor prognosis of esophageal adenocarcinoma in the Western world have intensified research efforts into earlier methods of detection of this disease and its relationship to Barrett's esophagus. The progression of Barrett's esophagus to adenocarcinoma has been the focus of particular scrutiny, and a number of potential tissue and serum-based disease biomarkers have emerged. The epidemiology and pathogenesis of esophageal adenocarcinoma are outlined. Tissue biomarkers allowing risk stratification of Barrett's are reviewed as well as strategies currently being used to discover novel biomarkers that will facilitate the early detection of esophageal adenocarcinoma. Finally, the uses of biomarkers as predictive tests for targeted treatments and as surrogate endpoints in chemoprevention trials are considered.

Cost-effectiveness of aspirin chemoprevention for Barrett's esophagus

BACKGROUND

Recent data suggest that nonsteroidal anti-inflammatory drugs, including aspirin, may prevent the progression of Barrett's esophagus to adenocarcinoma. However, use of aspirin is associated with numerous potential complications, including gastrointestinal bleeding and hemorrhagic strokes. We used a modeling approach to determine and compare the effectiveness and cost-effectiveness of aspirin with and without endoscopic surveillance to prevent esophageal adenocarcinoma.

METHODS

A Markov Monte Carlo decision model was constructed to compare four strategies for management of Barrett's esophagus: aspirin therapy, endoscopic surveillance with biopsies, both, or neither. Patients who took a daily enteric-coated aspirin were modeled to have a 50% reduction in the incidence of esophageal adenocarcinoma but could have complications related to therapy, at which point the aspirin was discontinued. Potential cardiac benefits of aspirin and its role in the chemoprevention of other cancers were not included in the analysis. The analysis was from a societal perspective from age 55 years until death. Sensitivity analyses were performed to investigate the effects of changes in model parameters on estimated costs and effectiveness outcomes across a wide range of assumptions.

RESULTS

Aspirin therapy was more effective and less costly than no therapy, resulting in 0.19 more quality-adjusted life years (QALYs). The combination of aspirin and endoscopic surveillance produced 0.27 more QALYs than no therapy at a cost of 13,400 U.S. dollars more, for an associated incremental cost-effectiveness ratio of 49,600 U.S. dollars/QALY. Aspirin use in combination with endoscopic surveillance dominated endoscopic surveillance alone, resulting in 0.06 more QALYs and 11,400 U.S. dollars less cost. The model's results were sensitive to increasing age and to decreased benefit or delay in aspirin's chemopreventive efficacy.

CONCLUSION

Using published values of parameters, regardless of whether a patient undergoes endoscopic surveillance, aspirin use in the management of Barrett's esophagus appears to be a cost-effective strategy to prevent esophageal adenocarcinoma.

Dysplasia in Barrett esophagus

BACKGROUND

Dysplasia in Barrett esophagus is a premalignant condition that is associated with an increased risk of developing esophageal adenocarcinoma. Unfortunately, clinical investigation aimed at prevention of progression to malignant disease has been hampered by the variable prevalence of dysplasia reported in the literature. The objective of the current study was to more accurately determine the prevalence of dysplasia among individuals with Barrett esophagus who would be available for enrollment in a chemoprevention trial.

METHODS

The pathology archives of 3 institutions were reviewed over a 5-year period for all reports of diagnoses of Barrett esophagus. Surgical cases, malignancies, and duplicate or referral cases were excluded from the analysis.

RESULTS

A total of 790 cases of Barrett esophagus were identified. Of these, 37 (4.7%) were cases of low-grade dysplasia (LGD), and 20 (2.5%) were cases of high-grade dysplasia. The University of Michigan Medical Center (Ann Arbor, MI) diagnosed 18 cases of LGD, Henry Ford Hospital (Detroit, MI) diagnosed 15 cases of LGD, and Brigham and Women's Hospital (Boston, MA) diagnosed 4 cases of LGD in patients with Barrett esophagus over the 5-year study period.

CONCLUSIONS

The confirmed low prevalence of cases of LGD will affect the design of future clinical trials of chemopreventive interventions for Barrett esophagus.

Clinical Manifestations and Esophageal Complications of GERD

This report focuses on the manifestations of gastroesophageal reflux disease (GERD) that are caused directly by contact between refluxed gastric juice and the esophageal mucosa. These manifestations include heartburn, peptic esophageal erosion and ulceration, peptic esophageal stricture, and Barrett esophagus. Peptic esophageal erosions and ulcerations are excavated defects in the esophageal mucosa that result when epithelial cells succumb to the caustic effects of refluxed acid and pepsin. Uncommonly, esophageal ulcers are complicated by hemorrhage, perforation, and penetration into the airway. Esophageal ulcers can stimulate fibrous tissue production and collagen deposition that result in stricture formation, and the ulcers can heal through a metaplastic process in which an intestinal-type epithelium replaces the damaged squamous cells (Barrett esophagus). The management of these conditions is discussed below.

Histopathological diagnosis of Barrett's mucosa and associated neoplasias: results of a consensus conference of the Working Group for Gastroenterological Pathology of the German Society for Pathology on 22 September 2001 in Erlangen

There are a number of difficulties regarding the diagnosis of Barrett's mucosa and the varying grades of neoplasia that may be associated with it. It was, therefore, the aim of a consensus conference of the Working Group for Gastroenterological Pathology within the German Society of Pathology to achieve standardisation regarding the following issues: definition and diagnostic criteria for Barrett's mucosa and its discrimination from intestinal metaplasia of the cardia, diagnostic criteria for intraepithelial neoplasia, number of biopsies necessary to establish the diagnosis, significance of additional immunohistochemical and/or molecular methods as well as importance of a second opinion in the diagnosis of intraepithelial neoplasia.

Role of cytology in the diagnosis of Barrett's esophagus and associated neoplasia

We studied 327 consecutive paired esophageal biopsies and brushing specimens obtained during the same endoscopic session to evaluate the role of cytology for the diagnosis of Barrett's esophagus (BE) and/or surveillance for associated dysplasia. A diagnosis of BE was based on the cytologic presence of goblet cells. Cases were reviewed and categorized into: 1) benign esophageal lesions (125 cases), with 48 cases of Candida (32 cases diagnosed by both techniques and 16 diagnosed only by cytology), 3 cases of herpes simplex with only 1 case diagnosed by cytology, and 74 cases of inflammation and/or repair; 2) benign BE (141 cases), with 74 cases (52%) diagnosed by both techniques, 11 cases by cytology only (8%), and 56 cases (40%) by histology only; 3) low-grade dysplasia (LGD, 30 cases), with 5 cases (17%) diagnosed with both specimens, one case (3%) by cytology only, and 24 cases (80%) by histology only; 4) high-grade dysplasia (HGD, 10 cases), with 8 cases (80%) diagnosed with both specimens, 1 case (10%) by cytology, and 1 case (10%) by histology; and 5) carcinomas (23 cases), with 20 cases (87%) diagnosed with both specimens, 2 cases (9%) by cytology only, and 1 case (4%) by histology only. Our results support the high degree of diagnostic accuracy of cytology for the diagnosis of Barrett's-associated HGD and/or carcinoma, and moderate sensitivity for BE.

Long-term endoscopic surveillance of patients with Barrett's esophagus. Incidence of dysplasia and adenocarcinoma: a prospective study

OBJECTIVE

Barrett's esophagus (BE) is a premalignant condition for which regular endoscopic follow-up is usually advised. We evaluated the incidence of esophageal adenocarcinoma (AC) in patients with BE and the impact of endoscopic surveillance on mortality from AC.

METHODS

A cohort of newly diagnosed BE patients was studied prospectively. Endoscopic and histological surveillance was recommended every 2 yr. Follow-up status was determined from hospital and registry office records and telephone calls to the patients.

RESULTS

From 1987 to 1997, BE was diagnosed in 177 patients. We excluded three with high-grade dysplasia (HGD) at the time of enrollment. Follow-up was complete in 166 patients (135 male, 31 female). The mean length of endoscopic follow-up was 5.5 yr (range 0.5-13.3). Low-grade dysplasia (LGD) was present initially in 16 patients (9.6%) and found during follow-up in another 24 patients. However, in 75% of cases, LGD was not confirmed on later biopsies. HGD was found during surveillance in three patients (1.8%), one with simultaneous AC; two with HGD developed AC later. AC was detected in five male patients during surveillance. The incidence of AC was 1/220 (5/1100) patient-years of total follow-up, or 1/183.6 (5/918) patient-years in subjects undergoing endoscopy. Four AC patients died, and one was alive with advanced-stage tumor. The mean number of endoscopies performed for surveillance, rather than for symptoms, was 2.4 (range 1-10) per patient. During the follow-up years the cohort had a total of 528 examinations and more than 4000 biopsies.

CONCLUSIONS

The incidence of AC in BE is low, confirming recent data from the literature reporting an overestimation of cancer risk in these patients. In our patient cohort, surveillance involved a large expenditure of effort but did not prevent any cancer deaths. The benefit of surveillance remains uncertain.

Follow-up for high-grade dysplasia in Barrett's esophagus

This article will focus on the value of endoscopic follow-up for patients with high-grade dysplasia (HGD). Because the diagnosis of HGD in Barrett's esophagus is not a simple straightforward task, the article first will discuss the controversies regarding the histological diagnosis, followed by a discussion of the importance of endoscopic imaging for making the clinical diagnosis of HGD, and a systematic review of the literature relating to the presence of synchronous cancers in patients with HGD and the occurrence of cancer during endoscopic follow-up in these patients (metachronous cancers). Furthermore, the article will also discuss endoscopic techniques currently available for surveillance of these patients and make recommendations regarding surveillance intervals and the optimal biopsy protocol.

The natural history of dysplasia and cancer in esophagitis and Barrett esophagus

The natural history of metaplasia and dysplasia in Barrett esophagus is not well defined. Publication bias, the selective reporting of studies that have positive or extreme results, has exaggerated the risk of esophageal adenocarcinoma in this condition. Recent data suggest that patients with Barrett esophagus develop these tumors at the rate of 0.5% per year, a cancer incidence considerably lower than was appreciated just a few years ago. Indirect evidence suggests that aggressive treatment of gastroesophageal reflux might decrease the risk of carcinogenesis, but no therapy yet has been proved to decrease the incidence of cancer in Barrett esophagus. Dysplasia in the metaplastic epithelium clearly is a worrisome finding, but the progression from dysplasia to cancer may take years and may not be inevitable.

Histology of Barrett's esophagus and dysplasia

This article explores issues related to the diagnosis of Barrett's esophagus (BE) in endoscopic biopsies and dysplasia in Barrett's epithelium. The definitions of BE, including long- and short-segment BE, are reviewed, with an emphasis on the significance of intestinal metaplasia (IM). IM of the gastroesophageal junction and cardia is reviewed and problems in its distinction from short-segment BE are discussed. In addition, the article reviews the classification of dysplasia in Barrett's mucosa, with reference to problematic areas, such as sampling error and interobserver variability. Biomarkers and their role in the diagnosis of dysplasia and stratification of risk are summarized.

Cyclo-oxygenase-2 expression in Barrett's oesophageal carcinogenesis: an immunohistochemical study

BACKGROUND

The incidence of Barrett's oesophageal adenocarcinoma is increasing more rapidly than any other malignancy in industrialized countries. Cyclo-oxygenase-2 appears to play an important role in gastrointestinal carcinogenesis. Previous studies on cyclo-oxygenase-2 expression in Barrett's oesophageal carcinogenesis have utilized tissue samples obtained from different patients. We sought a definitive comparison of cyclo-oxygenase-2 expression in the sequence of Barrett's metaplasia-dysplasia-adenocarcinoma within the same patients.

METHODS

Paraffin-embedded oesophago-gastrectomy specimens from 20 patients, containing successive stages of Barrett's metaplasia, high-grade dysplasia and adenocarcinoma, were analysed for cyclo-oxygenase-2 expression by immunohistochemistry.

RESULTS

Cyclo-oxygenase-2 was constitutively expressed in the basal layers of cells in the adjacent normal squamous oesophageal epithelium, but a higher cyclo-oxygenase-2 expression was observed in Barrett's metaplasia. A further increase in cyclo-oxygenase-2 expression was detected in high-grade dysplasia, but cyclo-oxygenase-2 was decreased in adenocarcinoma tissue, regardless of its stage or level of differentiation.

CONCLUSIONS

Cyclo-oxygenase-2 expression is progressively increased when squamous oesophageal epithelium develops into Barrett's metaplastic epithelium and then into high-grade dysplasia, but appears to decrease when adenocarcinoma develops. These findings may be significant for an effective chemo-prevention strategy with selective cyclo-oxygenase-2 inhibitors.

Esophageal complications of gastroesophageal reflux disease: Presentation, diagnosis, management, and outcomes

The esophageal complications of gastroesophageal reflux disease include peptic esophageal erosion and ulceration, peptic esophageal strictures, and Barrett's esophagus. Endoscopy is the diagnostic procedure of choice for the initial evaluation of lesions. For most patients, symptoms can be controlled with proton pump inhibitor (PPI) therapy. PPIs are also highly effective for healing esophageal erosions and ulcerations and for preventing recurrence of peptic esophageal strictures. Because Barrett's esophagus predisposes individuals to esophageal adenocarcinoma, these patients are advised to have regular endoscopic surveillance to detect early, curable neoplasms.

Barrett's esophagus and esophageal adenocarcinoma: pathogenesis, diagnosis, and therapy

Gastric juice that refluxes into the esophagus can injure esophageal squamous epithelium. When the injury heals through a metaplastic process in which an abnormal columnar epithelium replaces the injured squamous one, the resulting condition is called Barrett's esophagus. Gastroesophageal reflux disease and Barrett's esophagus are the most important risk factors for esophageal adenocarcinoma. This article examines such issues as the treatment, endoscopic surveillance, and chemoprevention of Barrett's esophagus. Also included are published guidelines and recommendations.

p53 expression in low grade dysplasia in Barrett's esophagus: correlation with interobserver agreement and disease progression

OBJECTIVES

The frequency of progression from low grade dysplasia (LGD) to high grade dysplasia/carcinoma (HGD/ CA) in Barrett's esophagus (BE) varies among studies. Current assessment is made more difficult because of pathologists' interobserver variability in diagnosing LGD. We recently conducted an interobserver study on LGD and reported a positive correlation between the extent of agreement among GI pathologists and progression of LGD. In the current study, we analyzed the immunohistochemical staining for p53 in patients diagnosed with LGD with known clinical outcome and interobserver agreement data.

METHODS

Fixed, paraffin-embedded endoscopic biopsy specimens from 16 patients diagnosed with LGD in BE were immunostained for p53 (DO-7, Dako, Carpinteria, CA). Hematoxylin and eosin-stained and immunostained sections were examined in tandem to determine whether the LGD areas in question stained for p53. The p53 immunoreactivity was correlated with clinical progression and with the interobserver agreement among three GI pathologists.

RESULTS

The overall mean follow-up was 23 months (range 2-84 months). LGD areas in seven of eight patients (88%) who progressed to HGD/CA stained positively for p53 compared to only two of eight nonprogressors (25%). A correlation with clinical progression was seen for p53 positivity (p = 0.017; log-rank test), and for either p53 positivity or complete agreement among three GI pathologists on LGD diagnosis (p = 0.014; log-rank test). The p53 staining demonstrated 88% sensitivity and 75% specificity for progression of LGD to HGD/CA. Adding complete interobserver agreement on LGD among three experienced GI pathologists to p53 positivity resulted in improved sensitivity with no change in specificity (100% and 75%, respectively).

CONCLUSIONS

In conjunction with histological evaluation by GI pathologists for a diagnosis of LGD, immunohistochemical staining for p53 can be used as an adjunctive test, as it correlated with progression to HGD/CA in this series.

Genetic pathways involved in the progression of Barrett's metaplasia to adenocarcinoma

BACKGROUND

The prediction of which patients with Barrett's metaplasia will develop cancer is difficult. Better genetic characterization of the condition may aid clinicians in devising more effective management and follow-up strategies.

METHODS

A review was undertaken of the accumulated genetic data relating to the progression of squamous epithelium to adenocarcinoma. The normal functions of a number of cancer-related genes are described and an explanation is given of how alterations in these genes interfere with normal cell processes and lead to cancer.

RESULTS AND CONCLUSION

The main genetic alterations accompanying the progression through dysplasia to adenocarcinoma were collated from 135 papers. The principal genetic changes implicated are the loss of p16 gene expression (by deletion or hypermethylation), the loss of p53 expression (by mutation and deletion), the increase in cyclin D1 expression, the induction of aneuploidy and the losses of the Rb, DCC and APC chromosomal loci.

Barrett's esophagus

Barrett's esophagus is an acquired condition resulting from severe esophageal mucosal injury. It still remains unclear why some patients with gastroesophageal reflux disease develop Barrett's esophagus whereas others do not. The diagnosis of Barrett's esophagus is established if the squamocolumnar junction is displaced proximal to the gastroesophageal junction and if intestinal metaplasia is detected by biopsy. Despite this seemingly simple definition, diagnostic inconsistencies remain a problem, especially in distinguishing short segment Barrett's esophagus from intestinal metaplasia of the gastric cardia. Barrett's esophagus would be of little importance were it not for its well-recognized association with adenocarcinoma of the esophagus. The incidence of esophageal adenocarcinoma continues to increase and the 5-year survival rate for this cancer remains dismal. However, cancer risk for a given patient with Barrett's esophagus is lower than previously estimated. Current strategies for improved survival in patients with esophageal adenocarcinoma focus on cancer detection at an early and potentially curable stage. This can be accomplished either by screening more patients for Barrett's esophagus or with endoscopic surveillance of patients with known Barrett's esophagus. Current screening and surveillance strategies are inherently expensive and inefficient. New techniques to improve the efficiency of cancer surveillance are evolving rapidly and hold the promise to change clinical practice in the future. Treatment options include aggressive acid suppression, antireflux surgery, chemoprevention, and ablation therapy, but there is still no clear consensus on the optimal treatment for these patients.

Endoscopy in Barrett's esophagus. Surveillance during reflux management and new advances in the diagnosis and early detection of dysplasia

Given the alarming rise in the incidence of esophageal cancer and the fact that Barrett's esophagus is clearly a precursor to this disease, effective surveillance is desirable. Endoscopic surveillance is recommended by major endoscopic and gastrointestinal societies based on the available data and hypothetic models suggest that the costs of endoscopic surveillance for Barrett's esophagus may be reasonable when compared with other commonly applied cancer screening strategies. Although, however, most implicated physicians agree that surveillance is warranted, recommended guidelines often are not followed. This occurrence may reflect the importance of some of the practical limitations inherent to carrying out intensive endoscopic biopsy protocols in large numbers of eligible patients. In an effort to improve the surveillance process, several new techniques have been tested and are in development. These techniques are aimed at facilitating the histologic sampling of larger areas of metaplastic epithelium, at better targeting sites more likely to harbor dysplasia and cancer, and at replacing endoscopic biopsies with nonhistologic tissue analysis. Although many of these newer techniques are promising, however, none are currently close to widespread clinical application. The current standard for surveillance remains the use of systematic endoscopic biopsies, with the frequency of surveillance endoscopies determined by the severity of any dysplastic changes that are found. Given the large number of patients that are likely to be eligible for screening and the current constraints in terms of physician availability and health-care resources, endoscopic biopsy will remain the cornerstone of Barrett's esophagus surveillance strategies unless newer alternatives are clearly advantageous in terms of accuracy, cost, availability, and ease of application. In the future, however, advances in techniques for minimally invasive ablation of Barrett's epithelium may make endoscopic surveillance obsolete altogether.

Dysplasia of the gut: the diagnosis is harder than it seems

Preneoplastic epithelia of the gut have been given several different names, but the one most often used is dysplasia. Dysplasias of the gut are diagnosed by pathologists, using a set of cytologic and architectural features, and are divided into two grades: low- and high-grade. Although the definitions imply that all low-grade dysplasias are similar (as are all high-grades), in reality, there is significant heterogeneity in the appearances of each grade of dysplasia. Thus, separating low-from high-grade epithelium may be difficult. In addition, the features that characterize low-grade epithelia are very similar to many examples of epithelial regeneration, and so these may not be readily separable. Such cases may be classified as being indefinite for dysplasia. For these reasons, and because the implications for patient care are significant, the interpretations of biopsies taken for dysplasia surveillance are considered challenging by most pathologists. Clinicians must understand the challenging nature of these biopsies, communicate with the pathologists who will interpret such biopsies, and obtain an adequate sample of the mucosa to ensure that dysplasia, if present, will be biopsied and appropriately diagnosed.