Preoperative chemotherapy unmasks underlying Barrett's mucosa in patients with adenocarcinoma of the distal esophagus

Salvage endoscopic resection in patients with esophageal adenocarcinoma after chemoradiotherapy

Background and study aims  For early esophageal adenocarcinoma, endoscopic resection is an accepted curative treatment with an excellent long-term prognosis. Case series from Japan have reported endoscopic resection of residual esophageal squamous cell carcinoma after chemoradiotherapy. This is the first report describing endoscopic resection of residual esophageal adenocarcinoma after chemoradiotherapy. Two patients with advanced esophageal adenocarcinoma had been treated with chemoradiotherapy because comorbidity precluded esophageal resection. When residual tumor was observed endoscopically, complete remission was achieved by salvage endoscopic therapy alone or in combination with argon plasma coagulation (APC). Both patients achieved long-term sustained remission and died of non-tumor-related causes.

Management of Barrett's esophagus with low-grade dysplasia

Barrett's esophagus progresses to esophageal adenocarcinoma in a stepwise histological fashion of no dysplasia, low grade dysplasia, high grade dysplasia and cancer. Hence the progression to cancer from various histological stages is different. Progression to cancer from low grade dysplasia is highly variable in the literature due to high inter-observer variability between pathologists in diagnosing it. Studies have shown the utility of having confirmation of low grade dysplasia by expert pathologists or documenting its persistence on two subsequent endoscopies in order to unify the diagnosis. The treatment of low grade dysplasia is variable. In this article we summarize the diagnosis, evaluation and management of low grade dysplasia in Barrett's Esophagus.

Genomic similarity between gastroesophageal junction and esophageal Barrett's adenocarcinomas

The current high mortality rate of esophageal adenocarcinoma (EAC) reflects frequent presentation at an advanced stage. Recent efforts utilizing fluorescent peptides have identified overexpressed cell surface targets for endoscopic detection of early stage Barrett's-derived EAC. Unfortunately, 30% of EAC patients present with gastroesophageal junction adenocarcinomas (GEJAC) and lack premalignant Barrett's metaplasia, limiting this early detection strategy. We compared mRNA profiles from 52 EACs (tubular EAC; tEAC) collected above the gastroesophageal junction with 70 GEJACs, 8 normal esophageal and 5 normal gastric mucosa samples. We also analyzed our previously published whole-exome sequencing data in a large cohort of these tumors. Principal component analysis, hierarchical clustering and survival-based analyses demonstrated that GEJAC and tEAC were highly similar, with only modest differences in expression and mutation profiles. The combined expression cohort allowed identification of 49 genes coding cell surface targets overexpressed in both GEJAC and tEAC. We confirmed that three of these candidates (CDH11, ICAM1 and CLDN3) were overexpressed in tumors when compared to normal esophagus, normal gastric and non-dysplastic Barrett's, and localized to the surface of tumor cells. Molecular profiling of tEAC and GEJAC tumors indicated extensive similarity and related molecular processes. Identified genes that encode cell surface proteins overexpressed in both Barrett's-derived EAC and those that arise without Barrett's metaplasia will allow simultaneous detection strategies.

Evolutionary dynamics in pre-invasive neoplasia

Mutational processes occur in normal tissues from conception throughout life. Field cancerization describes the preconditioning of an area of epithelium to tumor growth. Pre-invasive lesions may arise in these fields, however only a minority of pre-invasive neoplasia progresses to overt malignancy. Within this review we discuss recent advances in our understanding of genomic instability processes in normal tissue, describe evolutionary dynamics in pre-invasive disease and highlight current evidence describing how increasing genomic instability may drive the transition from pre-invasive to invasive disease. Appreciation of the evolutionary rulebooks that operate in pre-invasive neoplasia may facilitate screening strategies, risk-stratification of pre-invasive lesions and precipitate novel preventative treatments in at-risk patient populations.

A Systematic Review of Esophageal MicroRNA Markers for Diagnosis and Monitoring of Barrett's Esophagus

BACKGROUND

Esophageal epithelial microRNAs may be used to diagnose Barrett's esophagus (BE) and possibly monitor its progression to esophageal adenocarcinoma (EAC).

AIMS

We reviewed studies that have investigated this to identify microRNAs with high biomarker potential for screening and disease monitoring in BE.

METHODS

PubMed and EMBASE databases were searched for studies that quantified esophageal epithelial microRNAs. Publications reporting microRNA comparisons of normal, non-dysplastic BE, BE with high-grade dysplasia (HGD), and EAC tissues using both unbiased discovery and independent validation phases were reviewed.

RESULTS

Eleven studies on microRNA expression differences between normal epithelium and non-dysplastic BE (seven studies), HGD (4) or EAC (7), or between non-dysplastic BE and HGD (3) or EAC (6) were identified, and the findings of their validation phase were analyzed. Increased miR-192, -194, and -215, and reduced miR-203 and -205 expression in BE compared to normal was noticed by all 4-6 of the seven studies that examined these microRNAs. In heterogeneity tests of the reported fold-change values, the I (2) statistics were 7.9-17.1 % (all P < 0.05). Elevated miR-192, -194, and -215, and diminished miR-203 and -205 levels were also noted for comparisons of HGD or EAC against normal. In contrast, a consistent microRNA expression difference was absent for the comparisons of HGD or EAC against BE.

CONCLUSIONS

MicroRNAs miR-192, -194, -203, -205, and -215 are promising tissue biomarkers for diagnosing BE. Cross-sectional data suggest that microRNAs may have a limited role in separating BE from HGD/EAC epithelia but need further testing in longitudinal follow-up studies.

Development and Validation of a Classification System to Identify High-Grade Dysplasia and Esophageal Adenocarcinoma in Barrett's Esophagus Using Narrow-Band Imaging

BACKGROUND & AIMS

Although several classification systems have been proposed for characterization of Barrett's esophagus (BE) surface patterns based on narrow-band imaging (NBI), none have been widely accepted. The Barrett's International NBI Group (BING) aimed to develop and validate an NBI classification system for identification of dysplasia and cancer in patients with BE.

METHODS

The BING working group, composed of NBI experts from the United States, Europe, and Japan, met to develop a validated, consensus-driven NBI classification system for identifying dysplasia and cancer in BE. The group reviewed 60 NBI images of nondysplastic BE, high-grade dysplasia, and esophageal adenocarcinoma to characterize mucosal and vascular patterns visible by NBI; these features were used to develop the BING criteria. We then recruited adult patients undergoing surveillance or endoscopic treatment for BE at 4 institutions in the United States and Europe, obtaining high-quality NBI images and performing histologic analysis of biopsies. Experts individually reviewed 50 NBI images to validate the BING criteria, and then evaluated 120 additional NBI images (not previously viewed) to determine whether the criteria accurately predicted the histology results.

RESULTS

The BING criteria identified patients with dysplasia with 85% overall accuracy, 80% sensitivity, 88% specificity, 81% positive predictive value, and 88% negative predictive value. When dysplasia was identified with a high level of confidence, these values were 92%, 91%, 93%, 89%, and 95%, respectively. The overall strength of inter-observer agreement was substantial (κ = 0.681).

CONCLUSIONS

The BING working group developed a simple, internally validated system to identify dysplasia and EAC in patients with BE based on NBI results. When images are assessed with a high degree of confidence, the system can classify BE with >90% accuracy and a high level of inter-observer agreement.

Mechanisms of esophageal adenocarcinoma formation and approaches to chemopreventive intervention

The incidence of esophageal adenocarcinoma (EAC), a debilitating and highly lethal malignancy, has risen dramatically over the past 40 years in the United States and other Western countries. To reverse this trend, EAC prevention and early detection efforts by clinicians, academic researchers and endoscope manufacturers have targeted Barrett's esophagus (BE), the widely accepted EAC precursor lesion. Data from surgical, endoscopic and pre-clinical investigations strongly support the malignant potential of BE. For patients with BE, the risk of developing EAC has been estimated at 11- to 125-fold greater than that of the individual at average risk. Nevertheless, screening for BE in symptomatic patients (ie, with symptoms of reflux) and surveillance in patients diagnosed with BE have not had a substantial impact on the incidence, morbidity or mortality of EAC; the overwhelming majority of EAC patients are diagnosed without a pre-operative diagnosis of BE. This article will discuss the current state of the science of esophageal adenocarcinoma prevention, including ideas about carcinogenesis and its underlying genomic and molecular level mechanisms, and suggest strategies for a systems approach to targeted preventive management.

Screening for Barrett's Esophagus

The large increase in the incidence of esophageal adenocarcinoma in the West during the past 30 years has stimulated interest in screening for Barrett's esophagus (BE), a precursor to esophageal cancer. Effective endoscopic treatments for dysplasia and intramucosal cancer, coupled with screening programs to detect BE, could help reverse the increase in the incidence of esophageal cancer. However, there are no accurate, cost-effective, minimally invasive techniques available to screen for BE, reducing the enthusiasm of gastroenterologists. Over the past 5 years, there has been significant progress in the development of screening technologies. We review existing and developing technologies, new minimally invasive imaging techniques, nonendoscopic devices for cell collection, and biomarkers that can be measured in blood or stool samples. We discuss the status of these approaches, data from clinical studies of their effects, and their anticipated strengths and weaknesses in screening. The area is rapidly evolving, and new tools will soon be ready for prime time.

Esophageal Adenocarcinoma and Its Rare Association with Barrett's Esophagus in Henan, China

Incidence of esophageal adenocarcinoma (EAC) has increased sharply in Western Europe and United States over the past three decades. Nearly all cases of EAC in the west are thought to be associated with Barrett's esophagus (BE) at the time of diagnosis. Regions in the Henan province of China have one of world's highest incidences of esophageal cancer, yet recent temporal trends in the relative rates of EAC with respect to esophageal squamous-cell carcinoma (ESCC), as well as its association with Barrett's esophagus (BE), have not been reported. In this report, we present large-scale longitudinal clinical and histological data on 5401 esophageal cancers (EC) patients diagnosed during the recent 10-year period (2002-2011) at Henan Cancer Hospital, China. All 217 esophageal adenocarcinoma (EAC) patients from these 5401 EC patients were examined to better understand the relationship between Barrett's esophagus (BE) and EAC. We found that EAC was relatively rare and accounted for approximately 5% of all esophageal cancers each year during 2002-2011. There is no evidence of significant temporal trends in the rate of EAC relative to ESCC. Only 10 out of 217 (4.6%) EAC cases were detected to have any evidence of Barrett's esophagus. This result raises the possibility of a different etiological basis for EAC in China motivating more detailed epidemiological, clinical and molecular characterization of EAC in China in order to better understand the neoplastic development of EAC.

Progression of Barrett oesophagus: role of endoscopic and histological predictors

Barrett oesophagus is an important precursor lesion for the development of oesophageal adenocarcinoma (OAC). Upper gastrointestinal endoscopy is the modality most widely used to visualize and biopsy the oesophagus to establish a diagnosis. Additional clues are available at the time of endoscopy that can identify high-risk features known to increase the risk of progression to OAC, such as the length of the Barrett oesophagus segment, length of hiatal hernia and the presence of nodularity or visible endoscopic lesions in this segment. Until molecular biomarkers are identified and validated as adjunctive tools for risk stratification, knowledge of endoscopic features could complement dysplasia grading for risk stratification of patients with Barrett oesophagus and identify subgroups at risk of progression to OAC. This approach would, in turn, facilitate more rational tailoring of endoscopic surveillance. This Review summarizes the current role of endoscopic and histological factors involved in neoplastic progression of Barrett oesophagus to OAC, and provides an overview of the risk-prediction models that have utilized endoscopic and histological factors for risk stratification in patients with Barrett oesophagus.

Ordering of mutations in preinvasive disease stages of esophageal carcinogenesis

Cancer genome sequencing studies have identified numerous driver genes, but the relative timing of mutations in carcinogenesis remains unclear. The gradual progression from premalignant Barrett's esophagus to esophageal adenocarcinoma (EAC) provides an ideal model to study the ordering of somatic mutations. We identified recurrently mutated genes and assessed clonal structure using whole-genome sequencing and amplicon resequencing of 112 EACs. We next screened a cohort of 109 biopsies from 2 key transition points in the development of malignancy: benign metaplastic never-dysplastic Barrett's esophagus (NDBE; n=66) and high-grade dysplasia (HGD; n=43). Unexpectedly, the majority of recurrently mutated genes in EAC were also mutated in NDBE. Only TP53 and SMAD4 mutations occurred in a stage-specific manner, confined to HGD and EAC, respectively. Finally, we applied this knowledge to identify high-risk Barrett's esophagus in a new non-endoscopic test. In conclusion, mutations in EAC driver genes generally occur exceptionally early in disease development with profound implications for diagnostic and therapeutic strategies.

Total body fat and the risk of Barrett's oesophagus - a bioelectrical impedance study

BACKGROUND

Body mass index is associated with the risk of Barrett's oesophagus (BO). It is uncertain whether this is related to total body fat or other factors that correlate with body mass index. We aimed to quantify the association between total body fat (measured by bioelectrical impedance) and risk of BO and examine if this association was modified by gastro-oesophageal reflux (GOR) and abdominal obesity.

METHODS

In 2007-2009, we surveyed 235 cases (69% Males, Mean age 62.1 years) and 244 age and sex matched population controls from a population based case-control study of BO. We conducted structured interviews, standard anthropometry and bioimpedance analysis of total body fat. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using multivariable logistic regression analysis.

RESULTS

There was a significantly increased risk of BO among those in the highest tertile of total body fat weight (OR 2.01; 95%CI 1.26-3.21) and total body fat percentage (OR 1.86; 95%CI 1.10-3.15). These risks were largely attenuated after adjustment for GOR and waist circumference. There was a significantly increased risk of BO among those in the highest tertile of waist circumference (OR 2.21; 95%CI 1.39-3.51) and this was minimally attenuated after adjustment for total body fat and moderately attenuated after adjustment for GOR.

CONCLUSIONS

Total body fat is associated with an increased risk of BO but this appears to be mediated via both abdominal obesity and GOR. These findings provide evidence that abdominal obesity is more important than total body fat in the development of BO.

Strategies to improve outcomes in esophageal adenocarcinoma

Esophageal adenocarcinoma is one of the fastest rising cancers in Western society. Incidence has increased by 600% within the last 30 years. Rates of diagnosis and death run parallel due to the poor prognosis and a lack of effective treatments. Potentially curative treatments are followed by high rates of disease recurrence. For the majority of patients, who present with advanced disease, we have no effective treatment. We discuss the key areas of progress in this demanding field and offer our views on the direction of future research and treatment.

Carcinogenesis of Barrett's esophagus: a review of the clinical literature

Barrett's esophagus (BE) is a premalignant condition of esophageal adenocarcinoma (EAC). Although the incidence of BE has risen rapidly in the West, it is rare in Asia despite a recent increase in the prevalence of gastroesophageal reflux disease. Controversies over the definition of BE are presented because most cases show short-segment BE, especially ultra-short BE, in Asia. Here we review possible risk factors for the development of EAC, particularly possible roles of ethnicity, specialized intestinal metaplasia (SIM), BE length, and environmental factors, such as Helicobacter pylori infection and obesity. Additionally, we summarize recent studies on the effect of chemoprevention including proton pump inhibitors, nonsteroidal anti-inflammatory drugs or aspirin in order to reduce the risk of neoplastic progression in BE patients. Although substantial knowledge of risk factors of dysplasia/EAC in BE is shown, the risk for neoplastic development may be influenced by geographic variation, study population, the presence or absence of SIM or dysplasia at baseline, and the small number of BE patients investigated. Recently, the efficiency of surveillance for BE patients has been discussed from the standpoint of cost-effectiveness. It may be too difficult to draw conclusions because no randomized clinical trials of BE surveillance have been performed.

Temporal and spatial evolution of somatic chromosomal alterations: a case-cohort study of Barrett's esophagus

All cancers are believed to arise by dynamic, stochastic somatic genomic evolution with genome instability, generation of diversity, and selection of genomic alterations that underlie multistage progression to cancer. Advanced esophageal adenocarcinomas have high levels of somatic copy number alterations. Barrett's esophagus is a risk factor for developing esophageal adenocarcinoma, and somatic chromosomal alterations (SCA) are known to occur in Barrett's esophagus. The vast majority (∼95%) of individuals with Barrett's esophagus do not progress to esophageal adenocarcinoma during their lifetimes, but a small subset develop esophageal adenocarcinoma, many of which arise rapidly even in carefully monitored patients without visible endoscopic abnormalities at the index endoscopy. Using a well-designed, longitudinal case-cohort study, we characterized SCA as assessed by single-nucleotide polymorphism arrays over space and time in 79 "progressors" with Barrett's esophagus as they approach the diagnosis of cancer and 169 "nonprogressors" with Barrett's esophagus who did not progress to esophageal adenocarcinoma over more than 20,425 person-months of follow-up. The genomes of nonprogressors typically had small localized deletions involving fragile sites and 9p loss/copy neutral LOH that generate little genetic diversity and remained relatively stable over prolonged follow-up. As progressors approach the diagnosis of cancer, their genomes developed chromosome instability with initial gains and losses, genomic diversity, and selection of SCAs followed by catastrophic genome doublings. Our results support a model of differential disease dynamics in which nonprogressor genomes largely remain stable over prolonged periods, whereas progressor genomes evolve significantly increased SCA and diversity within four years of esophageal adenocarcinoma diagnosis, suggesting a window of opportunity for early detection.

Screening for precancerous lesions of upper gastrointestinal tract: from the endoscopists' viewpoint

Upper gastrointestinal tract cancers are one of the most important leading causes of cancer death worldwide. Diagnosis at late stages always brings about poor outcome of these malignancies. The early detection of precancerous or early cancerous lesions of gastrointestinal tract is therefore of utmost importance to improve the overall outcome and maintain a good quality of life of patients. The desire of endoscopists to visualize the invisibles under conventional white-light endoscopy has accelerated the advancements in endoscopy technologies. Nowadays, image-enhanced endoscopy which utilizes optical- or dye-based contrasting techniques has been widely applied in endoscopic screening program of gastrointestinal tract malignancies. These contrasting endoscopic technologies not only improve the visualization of early foci missed by conventional endoscopy, but also gain the insight of histopathology and tumor invasiveness, that is so-called optical biopsy. Here, we will review the application of advanced endoscopy technique in screening program of upper gastrointestinal tract cancers.

Effects of dropping the requirement for goblet cells from the diagnosis of Barrett's esophagus

BACKGROUND & AIMS

The 2011 American Gastroenterological Association diagnostic criteria for Barrett's esophagus (BE) require the presence of goblet cells in biopsy specimens of columnar mucosa within the esophagus. In other countries, patients can be diagnosed with BE based on evidence of columnar epithelium, regardless of the presence of goblet cells. We examined the effects that a broader criteria would have on diagnoses of patients with endoscopically suspected BE. We also compared the clinical outcomes of patients with and without goblet cells in esophageal biopsy samples.

METHODS

We analyzed the University of Chicago Medical Center database to identify 690 patients with no previous history of BE who underwent endoscopic biopsy analysis for BE from 1987 to 2008. We collected endoscopy reports, histology results, and chart reviews.

RESULTS

Of biopsy specimens analyzed, samples from 258 patients contained goblet cells and 379 did not (53 of the biopsy samples contained only squamous mucosa). Patients whose biopsy samples contained goblet cells had longer endoscopic columnar segments (mean, 4.6 cm) and more biopsy specimens taken (mean, 5 biopsy specimens) than those without (mean length, 1.6 cm; mean, 4 biopsy specimens). Of patients whose biopsy specimens did not contain goblet cells, 35% underwent additional endoscopy; goblet cells continued to be absent in 88% of these (mean follow-up time, 5.8 y; 2.8 additional procedures; mean total biopsy specimens, 12). Goblet cells were identified in only 19% of all patients with columnar mucosa less than 2 cm. No patient without goblet cells developed adenocarcinoma.

CONCLUSIONS

Decreasing the requirement for goblet cells would increase the diagnosis of BE by 147%. Among patients with short columnar segments, subsequent endoscopy generally does not reveal goblet cells, so the columnar mucosa might represent proximal stomach. Decreasing the requirement for goblet cells would cause many patients to be inaccurately labeled as BE.

The risk of Barrett's esophagus associated with abdominal obesity in males and females

Esophageal adenocarcinoma arises from Barrett's esophagus (BE). Both occur predominantly in males. The role of abdominal obesity in this sex distribution is uncertain. Our study aimed to determine whether there is an association between abdominal obesity and risk of BE and if present was it modified by sex. A structured interview and anthropometric measures were conducted within a population-based case-control study. We recruited 237 BE cases (70% male) and 247 population controls, frequency matched by age and sex. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariable logistic regression analysis. In the overall group and males, all measures of abdominal obesity [waist circumference (WC), waist-hip ratio (WHR), sagittal abdominal diameter (SAD) and waist-height ratio (WHtR)] were strongly associated with risk of BE (Overall: WC OR 2.2 95% CI 1.4-3.5, WHR 1.8 95% CI 1.2-2.9, SAD 2.3 95% CI 1.4-3.7, WHtR 1.9 95% CI 1.2-3.0, males WC 2.5 95% CI 1.4-4.3, WHR 2.4 95% CI 1.3-4.2, SAD 2.5 95% CI 1.4-4.3, WHtR 1.9 95% CI 1.1-3.4). These associations were minimally attenuated by adjusting for ever-symptoms of gastroesophageal reflux (GER). These findings suggest in males, non-GER factors related to abdominal obesity may be important in the development of BE. In females, there was modest association between measures of abdominal obesity and risk of BE but these were all abolished after adjusting for ever-symptoms of GER. The power to detect differences between sexes in the risk of BE associated with abdominal obesity was limited by the number of females in the study.

Columnar-lined esophagus without intestinal metaplasia has no proven risk of adenocarcinoma

Intestinal metaplasia in the columnar-lined esophagus (CLE) has long been recognized as the most significant histologic risk indicator for esophageal adenocarcinoma. Recent concern has been expressed, however, that nonintestinalized metaplastic columnar epithelia (cardiac epithelium in the esophagus) may also indicate risk. Of 2586 consecutive patients undergoing endoscopy and biopsy in the Foregut Surgery Department, we selected (a) 214 patients with a visible CLE who had systemic 4-quadrant biopsies at 1 to 2 cm intervals, with the most proximal biopsy straddling the squamocolumnar junction, and (b) 109 patients without systematic biopsy who had dysplasia or adenocarcinoma. In the first group, 187 (87.4%) patients had intestinal metaplasia, and 27 (12.6%) had cardiac epithelium. Dysplasia or adenocarcinoma was present in 55 patients, all with intestinal metaplasia; its presence was significantly higher than in the cardiac epithelium group, none of whom had dysplasia or adenocarcinoma (P=0.01). In the second group with limited sampling, 49 had only tumor tissue in the biopsy. Of 60 patients with nontumor epithelium, only 34 (56.7%) had residual intestinal metaplasia. We conclude that systematic biopsies of CLE as described in this study separate patients into those with and without intestinal metaplasia in such a manner as to remove the possibility of false-negative diagnosis of intestinal metaplasia. When intestinal metaplasia is absent using this biopsy protocol, the patient is at no or extremely low risk for dysplasia and cancer. When biopsies have a lower level of sampling of the segment of CLE, the absence of intestinal metaplasia cannot be interpreted as a true negative for intestinal metaplasia. Inadequate sampling is a powerful reason why the near absolute association between intestinal metaplasia and adenocarcinoma is not seen in some studies.

Barrett's esophagus with high-grade dysplasia: Focus on current treatment options

High-grade dysplasia (HGD) in Barrett’s esophagus (BE) is the critical step before invasive esophageal adenocarcinoma. Although its natural history remains unclear, an aggressive therapeutic approach is usually indicated. Esophagectomy represents the only treatment able to reliably eradicate the neoplastic epithelium. In healthy patients with reasonable life expectancy, vagal-sparing esophagectomy, with associated low mortality and low early and late postoperative morbidity, is considered the treatment of choice for BE with HGD. Patients unfit for surgery should be managed in a less aggressive manner, using endoscopic ablation or endoscopic mucosal resection of the entire BE segment, followed by lifelong surveillance. Patients eligible for surgery who present with a long BE segment, multifocal dysplastic lesions, severe reflux symptoms, a large fixed hiatal hernia or dysphagia comprise a challenging group with regard to the appropriate treatment, either surgical or endoscopic.

Cryoablation of persistent Barrett's epithelium after definitive chemoradiation therapy for esophageal adenocarcinoma

BACKGROUND

Dysplastic Barrett's epithelium (BE) persists after chemoradiation therapy for esophageal adenocarcinoma (EAC) arising in Barrett's esophagus. This phenomenon may present a significant risk for development of metachronous adenocarcinoma.

OBJECTIVE

To analyze the safety and efficacy of endoscopic cryoablation therapy for persistent dysplastic BE in patients with complete clinical response after definitive chemoradiation therapy for EAC.

DESIGN

Retrospective cohort study.

SETTING

Single National Cancer Institute Comprehensive Cancer Center experience.

PATIENTS

Radiation and endoscopic oncology treatment records were reviewed between January 2004 and September 2009. Fourteen patients with EAC who had been treated with definitive chemoradiation therapy followed by cryoablation were identified.

INTERVENTION

Cryoablation therapy.

MAIN OUTCOME MEASUREMENTS

Reduction in Prague Classification and dysplasia status following cryoablation therapy. Complications reported at 24 hour after the procedure telephone survey and at subsequent endoscopy.

RESULTS

After complete clinical response of EAC to chemoradiation therapy, the median length of persistent BE was Prague classification C1M4 (C = circumferential extent, M = maximal extent). Cryoablation reduced the median length of persistent BE to Prague classification C0M1 (P = .009 with respect to circumferential extent and P = .004 with respect to maximal extent of BE). All 14 patients had dysplastic BE. Cryoablation resulted in histological downgrading in all 14 patients. Among patients with high-grade dysplasia, 20% (2/10) were reduced to low-grade dysplasia, 60% (6/10) to BE with no dysplasia, and 20% (2/10) to no BE. Among patients with low-grade dysplasia, 75% (3/4) were reduced to BE with no dysplasia, and 25% (1/4) to no BE. The median number of cryoablation treatments administered to the 14 patients evaluated was 1 (mean 1.5, range 1-5). Eighty-six percent (12/14) of patients reported no complaints during the 24 hours after cryoablation. No occurrences of perforation and no esophageal strictures were reported at surveillance endoscopy.

LIMITATIONS

Single-center, retrospective design involving a small number of patients.

CONCLUSION

Our observations suggest that cryoablation therapy is safe and effective for the treatment of persistent BE after definitive chemoradiation.

Barrett's esophagus: a review of the literature

Barrett's esophagus (BE) is the premalignant lesion of esophageal adenocarcinoma (EAC) defined as specialized intestinal metaplasia of the tubular esophagus that results from chronic gastroesophageal reflux. Which patients are at risk of having BE and which are at further risk of developing EAC has yet to be fully established. Many aspects of the management of BE have changed considerably in the past 5 years alone. The aim of this review is to define the critical elements necessary to effectively manage individuals with BE. The general prevalence of BE is estimated at 1.6-3% and follows a demographic distribution similar to EAC. Both short-segment (<3 cm) and long-segment (≥3 cm) BE confer a significant risk for EAC that is increased by the development of dysplasia. The treatment for flat high-grade dysplasia is endoscopic radiofrequency ablation therapy. The benefits of ablation for non-dysplastic BE and BE with low-grade dysplasia have yet to be validated. By understanding the intricacies of the development, screening, surveillance, and treatment of BE, new insights will be gained into the prevention and early detection of EAC that may ultimately lead to a reduction in morbidity and mortality in this patient population.

LgR5 expression and cancer stem cell hypothesis: clue to define the true origin of esophageal adenocarcinomas with and without Barrett's esophagus?

Background

Investigation of the expression of an intestinal stem cell marker in esophageal adenocarcinomas (EAC) with and without Barrett's Esophagus (BE), with respect to a cancer stem cell (CSC) hypothesis.

Materials and methods

Expression of a putative intestinal stem cell marker LgR5 was analyzed in esophageal cancer specimen (n = 70: 41 EAC with BE, 19 EAC without BE, and n = 10 esophageal squamous-cell carcinomas, ESCC) and in the adenocarcinoma cell line OE-33. Ki-67 and Cdx-2 were co-labelled with LgR5 in double staining experiments. Immunhistochemical expression results were confirmed by RT-PCR and correlated with tumor stage and five-year survival rates.

Results

LgR5was found expressed in 35 of 41 (85%) EAC with BE and in 16 of 19 (81%) EAC without BE. By contrast, LgR5 was not found to be expressed in ESCC. Quantification of immunolabeling showed 15% LgR5+ cells in EAC with BE, 32% LgR5+ cells in adjacent BE and 13% in EAC without BE. Immunofluorescence double staining experiments with LgR5 and Ki-67 revealed a subpopulation (~5%) of proliferating LgR+/Ki-67+ cells. On mRNA-level, expression of LgR5 was higher in BE in comparison to EAC (p = 0.0159). High levels of LgR5 expression in BE associated EAC were associated with poorer survival in univariate analysis.

Conclusion

The stem cell marker LgR5 is expressed in EAC, irrespective of association with BE, and appears to have negative impact on survival. The subset of proliferating LgR5+ cells (<5%) might resemble rapidly cycling CSCs, which needs to be substantiated in further investigations.

Does Barrett's esophagus respond to chemoradiation therapy for adenocarcinoma of the esophagus?

BACKGROUND

Adenocarcinoma of the esophagus is frequently associated with Barrett's esophagus (BE). The response of esophageal adenocarcinoma to chemoradiation therapy is well described; however, the effect of chemoradiation on tumor-associated BE has not been specifically reported.

OBJECTIVE

To determine the response of tumor-associated BE to chemoradiation therapy.

DESIGN

Retrospective cohort study.

SETTING

A single National Cancer Institute Comprehensive Cancer Care Center experience.

PATIENTS

The study cohort consisted of 43 patients with stage I to IVA esophageal adenocarcinoma associated with BE who received either neoadjuvant or definitive chemoradiation therapy and underwent either esophagectomy or surveillance at our institution.

MAIN OUTCOME MEASUREMENT

The presence and extent of BE after chemoradiation therapy of esophageal adenocarcinoma associated with endoscopically documented pretreatment BE.

RESULTS

BE persisted after chemoradiation therapy in 93% (40/43) of cases (95% CI, 83%-99%). Twenty-seven patients received neoadjuvant chemoradiation therapy before esophagectomy. Persistent BE was detected in all 27 surgical specimens (100%). In 59% (16/27) of the cases, there was complete pathologic tumor response. Sixteen patients received definitive chemoradiation therapy. Persistent pretreatment BE was identified in 88% (14/16) by surveillance endoscopy (95% CI, 60%-98%). The mean length of BE before and after chemoradiation was 6.6 cm and 5.8 cm, respectively (P = .38).

LIMITATIONS

Retrospective design, small sample size, and single-site data collection.

CONCLUSIONS

Chemoradiation therapy of esophageal adenocarcinoma does not eliminate tumor-associated BE, nor does it affect the length of the BE segment.

Treatment for Barrett's oesophagus

BACKGROUND

Treatments for Barrett's oesophagus, the precursor lesion of adenocarcinoma, are available but whether these therapies effectively prevent the development of adenocarcinoma, and in some cases eradicate the Barrett's oesophagus segment, remains unclear.

OBJECTIVES

To summarise, quantify and compare the efficacy of pharmacological, surgical and endoscopic treatments for the eradication of dysplastic and non-dysplastic Barrett's oesophagus and prevention of these states from progression to adenocarcinoma.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library 2004, issue 4), MEDLINE (1966 to June 2008) and EMBASE (1980 to June 2008).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing medical, endoscopic or non-resectional surgical treatments for Barrett's oesophagus. The primary outcome measures were complete eradication of Barrett's and dysplasia at 12 months, and reduction in the number of patients progressing to cancer at five years or latest time point.

DATA COLLECTION AND ANALYSIS

Three authors independently extracted data and assessed the quality of the trials included in the analysis.

MAIN RESULTS

Sixteen studies, including 1074 patients, were included. The mean number of participants in the studies was small (n = 49; range 8 to 208). Most studies did not report on the primary outcomes. Medical and surgical interventions to reduce symptoms and sequelae of gastro-oesophageal reflux disease (GORD) did not induce significant eradication of Barrett's oesophagus or dysplasia. Endoscopic therapies (photodynamic therapy (PDT with aminolevulinic acid or porfimer sodium), argon plasma coagulation (APC) and radiofrequency ablation (RFA)) all induced regression of Barrett's oesophagus and dysplasia. The data for photodynamic therapy were heterogeneous with a mean eradication rate of 51% for Barrett's oesophagus and between 56% and 100% for dysplasia, depending on the treatment regimens. The variation in photodynamic therapy eradication rates for dysplasia was dependent on the drug, source and dose of light. Radiofrequency ablation resulted in eradication rates of 82% and 94% for Barrett's oesophagus and dysplasia respectively, compared to a sham treatment. Endoscopic treatments were generally well tolerated, however all were associated with some buried glands, particularly following argon plasma coagulation and photodynamic therapy, as well as photosensitivity and strictures induced by porfimer sodium based photodynamic therapy in particular.

AUTHORS' CONCLUSIONS

Despite their failure to eradicate Barrett's oesophagus, the role of medical and surgical interventions to reduce the troubling symptoms and sequelae of GORD is not questioned. Whether therapies for GORD reduce the cancer risk is not yet known. Ablative therapies have an increasing role in the management of dysplasia within Barrett's and current data would favour the use of radiofrequency ablation compared with photodynamic therapy. Radiofrequency ablation has been shown to yield significantly fewer complications than photodynamic therapy and is very efficacious at eradicating both dysplasia and Barrett's itself. However, long-term follow-up data are still needed before radiofrequency ablation can be used in routine clinical care without the need for very careful post-treatment surveillance. More clinical trial data and in particular randomised controlled trials are required to assess whether or not the cancer risk is reduced in routine clinical practice.

Risk factors for Barrett’s oesophagus and oesophageal adenocarcinoma: Results from the FINBAR study

AIM: To investigate risk factors associated with Barrett’s oesophagus and oesophageal adenocarcinoma.

METHODS: This all-Ireland population-based case-control study recruited 224 Barrett’s oesophagus patients, 227 oesophageal adenocarcinoma patients and 260 controls. All participants underwent a structured interview with information obtained about potential lifestyle and environmental risk factors.

RESULTS: Gastro-oesophageal reflux was associated with Barrett’s [OR 12.0 (95% CI 7.64-18.7)] and oesophageal adenocarcinoma [OR 3.48 (95% CI 2.25-5.41)]. Oesophageal adenocarcinoma patients were more likely than controls to be ex- or current smokers [OR 1.72 (95% CI 1.06-2.81) and OR 4.84 (95% CI 2.72-8.61) respectively] and to have a high body mass index [OR 2.69 (95% CI 1.62-4.46)]. No significant associations were observed between these risk factors and Barrett's oesophagus. Fruit but not vegetables were negatively associated with oesophageal adenocarcinoma [OR 0.50 (95% CI 0.30-0.86)].

CONCLUSION: A high body mass index, a diet low in fruit and cigarette smoking may be involved in the progression from Barrett’s oesophagus to oesophageal adenocarcinoma.

Erosive esophagitis and nonerosive reflux disease (NERD): comparison of epidemiologic, physiologic, and therapeutic characteristics

Nonerosive reflux disease (NERD) and erosive esophagitis are the main presentations of gastroesophageal reflux disease. However, NERD is the most common presentation of gastroesophageal reflux disease in community-based patients. Patients with NERD differ in demographic characteristics from patients with erosive esophagitis, primarily in sex distribution, weight/body mass index, and prevalence of hiatal hernia. Physiologically, patients with NERD tend to have normal lower esophageal sphincter resting pressure, minimal esophageal body motility abnormalities, low esophageal acid exposure profile and minimal nighttime esophageal acid exposure. Patients with NERD have a lower symptom response rate to proton pump inhibitor once daily than patients with erosive esophagitis. Additionally, NERD patients demonstrate a longer lag-time for symptom resolution and lack of difference in symptom response rate between half to full dose proton pump inhibitor as compared with patients with erosive esophagitis.

Surgical management of esophagogastric junction tumors

Surgical resection with lymphadenectomy is the mainstay of treatment for all resectable esophagogastric junction tumors, prior to systemic generalization of the disease. This makes accurate pre-treatment staging and classification of the tumors most demanding. A well-established and internationally accepted classification for adenocarcinomas of the esophagogastric junction (AEG) helps to choose the appropriate surgical approach and to make results from different institutions comparable. Distal esophageal adenocarcinomas (AEGI) are distinguished from true cardia carcinomas (AEG II) and subcardiac gastric cancers (AEG III). Substantial advancements in this surgical field during the preceding decades have clearly revealed that individualization of the surgical strategy is the key to successfully approaching these entities. In this review we discuss the surgical management of esophagogastric junction tumors with a tailored surgical strategy.

Prognostic factors in adenocarcinoma of the esophagus or gastroesophageal junction

The incidence of adenocarcinoma of the esophagus is rising rapidly in Western Europe and North America. It is an aggressive disease with early lymphatic and hematogenous dissemination. TNM cancer staging systems predict survival on the basis of the anatomic extent of the tumor. However, the adequacy of the current TNM staging system for adenocarcinoma of the esophagus or gastroesophageal junction (GEJ) is questioned repeatedly. Numerous prognostic factors have been described, but are not included in the TNM system. This review describes clinical parameters, aspects of operative technique, response to preoperative chemoradiotherapy therapy, complications and established pathologic determinants found in the resection specimen that have a prognostic impact. Furthermore, their potential application in the clinical setting in patients with adenocarcinoma of the esophagus or GEJ is discussed. Future directions to improve staging systems are given.

Preferred location for the development of esophageal adenocarcinoma within a segment of intestinal metaplasia

BACKGROUND

Barrett's metaplasia is the predominant precursor for the development of esophageal adenocarcinoma. This precancerous lesion has become the focus of various surveillance programs aimed at detecting earlier and therefore potentially curable lesions. However, sampling error by missing invasive cancer lesions is a common problem. This study aimed to identify preferred locations within a segment of Barrett's mucosa for the development of esophageal adenocarcinoma.

METHODS

The study group consisted of 213 patients with histologically proven esophageal adenocarcinoma. Of those, there were 134 cases of early cancer and 79 cases of locally advanced lesions. These patients received neoadjuvant chemotherapy. The frequency of intestinal metaplasia and the location of the tumor occurrence within the segment of intestinal metaplasia were assessed.

RESULTS

Intestinal metaplasia was found in 83% of the early lesions and in 98% of the advanced tumors after neoadjuvant chemotherapy. In 82.2% of the cases, the tumor was located at the distal margin of the intestinal metaplasia in patients with early tumor manifestations. The remaining tumor mass after neoadjuvant therapy also was located predominantly at the distal margin of the segment of intestinal metaplasia (85% of the cases).

CONCLUSIONS

The results demonstrate that almost all adenocarcinomas of the esophagus are based on the development of a segment of intestinal metaplasia. The distal margin of Barrett's mucosa seems to be the most vulnerable location for the development of invasive cancer.

Differential Response to Preoperative Chemoradiation and Surgery in Esophageal Adenocarcinomas Based on Presence of Barrett's Esophagus and Symptomatic Gastroesophageal Reflux

BACKGROUND

Barrett's esophagus and gastroesophageal reflux disease (GERD) are recognized to predispose to esophageal adenocarcinoma. Abdel-Latif and colleagues recently suggested that esophageal adenocarcinoma patients with GERD might be resistant to multimodality treatment. In this study, we investigated potential differences in clinical outcomes in esophageal adenocarcinoma patients based on the presence of identifiable Barrett's mucosa and/or history of symptomatic GERD.

METHODS

Eighty-four patients with resectable esophageal adenocarcinoma, who completed the planned preoperative chemoradiation and underwent a potentially curative esophageal resection were retrospectively evaluated. Postoperative survival was compared between patients with or without underlying Barrett's esophagus and history of symptomatic GERD. Patients with pathologic complete response (path CR) and those with partial or no response (path PR) were compared to determine if presence of Barrett's esophagus and history of symptomatic GERD influence the path CR rates.

RESULTS

We found significantly lower postoperative survival in patients with Barrett's associated adenocarcinoma (vs adenocarcinoma arising de novo, p = 0.031) and patients with symptomatic GERD (vs patients without symptomatic GERD, p = 0.019). Furthermore, the subset of patients with path PR (vs path CR) after chemoradiation have a significantly higher proportion of patients with Barrett's esophagus (HR = 4.38, confidence interval [CI] = 1.39 to 13.83, p = 0.012) and patients with GERD (HR = 2.71, CI = 1.13 to 6.50, p = 0.026).

CONCLUSIONS

Patients with esophageal adenocarcinoma may have differences in response to preoperative chemoradiation based on the presence of Barrett's esophagus and history of symptomatic GERD.

Carcinoma of the cardia: classification as esophageal or gastric cancer?

INTRODUCTION

The cardia is the anatomical borderland between the esophagus and stomach. Carcinomas of the cardia are regarded to share features of both, esophageal and gastric cancers. Controversy exists concerning their appropriate classification and whether these tumors comprise--in respect to tumor biology, pathophysiology as well as clinical features--an entirely separate entity.

CLASSIFICATION

In order to distinguish cardia carcinomas from other adenocarcinomas arising within the vicinity of the esophagogastric junction, a classification system has been introduced from a surgical viewpoint, and is now well established and increasingly used worldwide. According to the topography of the main tumor mass, cardia carcinomas (AEG II) are distinguished from adenocarcinomas of the distal esophagus (AEG I) and subcardiac gastric cancers (AEG III). The tumor-node-metastasis (TNM) staging system by the International Union Against Cancer (UICC) does not provide a separate classification for tumors of the esophagogastric junction. The use of the classification for esophageal or for gastric cancers is recommended, irrespective of the elementary differences in the classification of lymphatic spread implemented herein.

DISCUSSION

New aspects concerning this controversial debate are discussed based on current insights into the pathogenesis and the cellular origin of these entities. The controversies concerning the classification of cardia carcinomas and the failure of the current esophageal and gastric cancer staging systems to reflect the peculiarities of this entity accurately, present a strong argument in favor of a new classification system.

Epidemiology, pathophysiology, and treatment of Barrett's esophagus: reducing mortality from esophageal adenocarcinoma

The definition of BE has evolved over time. BE is the key premalignant lesion for developing EAC. The epidemiology and pathophysiology of BE is outlined, and risk factors for BE and EAC are reviewed. GERD plays a crucial role in the pathophysiology and the clinical identification of BE. Endoscopy with biopsy is the best tool for diagnosing and surveying patients with BE. Detection of early neoplasia is the present approach to reduce EAC mortality. Novel technology should assist in the early detection of dysplasia to enable targeted therapy. Effective chemopreventive strategies may reduce the risk of progression to EAC.

A critical review of the diagnosis and management of Barrett's esophagus: the AGA Chicago Workshop

BACKGROUND & AIMS

The diagnosis and management of Barrett's esophagus (BE) are controversial. We conducted a critical review of the literature in BE to provide guidance on clinically relevant issues.

METHODS

A multidisciplinary group of 18 participants evaluated the strength and the grade of evidence for 42 statements pertaining to the diagnosis, screening, surveillance, and treatment of BE. Each member anonymously voted to accept or reject statements based on the strength of evidence and his own expert opinion.

RESULTS

There was strong consensus on most statements for acceptance or rejection. Members rejected statements that screening for BE has been shown to improve mortality from adenocarcinoma or to be cost-effective. Contrary to published clinical guidelines, they did not feel that screening should be recommended for adults over age 50, regardless of age or duration of heartburn. Members were divided on whether surveillance prolongs survival, although the majority agreed that it detects curable neoplasia and can be cost-effective in selected patients. The majority did not feel that acid-reduction therapy reduces the risk of esophageal adenocarcinoma but did agree that nonsteroidal antiinflammatory drugs are associated with a cancer risk reduction and are of promising (but unproven) value. Participants rejected the notion that mucosal ablation with acid suppression prevents adenocarcinoma in BE but agreed that this may be an appropriate strategy in a subgroup of patients with high-grade dysplasia.

CONCLUSIONS

Based on this review of BE, the opinions of workshop members on issues pertaining to screening and surveillance are at variance with published clinical guidelines.

Distinct phenotypic presentations of gastroesophageal reflux disease: a new view of the natural history

For decades the natural history of gastroesophageal reflux disease (GERD) has been approached as spectrum-continuum, emphasizing the potential progress over time of patients along the spectrum. This commonly adopted conceptual framework had a profound impact on the field, affecting our research priorities and current management of GERD patients. A recent new conceptual framework has been proposed, suggesting that in response to factors that promote gastroesophageal reflux, patients may develop 3 distinct phenotypic presentations: non-erosive reflux disease; erosive esophagitis, and Barrett's esophagus. Most studies thus far, albeit unsatisfactory in their design, have demonstrated a very limited movement in between the 3 phenotypic presentations of GERD, further suggesting that those once determined remain true to form. The new conceptual framework emphasizes the importance of understanding symptom generation in GERD and the need to focus on the etiology and management of each phenotypic presentation of GERD. Additionally, it supports the usage of on-demand or intermittent antireflux treatment in clinical practice and provides better understanding of one of the most important clinical dilemmas - proton pump inhibitor failure.

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.

Barrett esophagus

PURPOSE

The importance of an in-depth understanding about Barrett esophagus is ultimately to decrease the mortality and morbidity from esophageal adenocarcinoma cancer by early detection of metaplasia and dysplasia and appropriate therapy. This review summarizes several publications in the past year related to the epidemiology, pathogenesis, screening and surveillance, new methods for detection of metaplasia/dysplasia, and advances in the treatment of Barrett esophagus.

RECENT FINDINGS

Patients with Barrett esophagus are characterized by the presence of risk factors usually indicative of severe types of gastroesophageal reflux disease. Recent insights into epidemiology and pathogenesis have shown that the risk of high-grade dysplasia and adenocarcinoma may be related to the increasing length of Barrett esophagus, size of hiatus hernia, and severity of acid reflux. The role of smoking and alcohol consumption remains controversial. Increasing the number of biopsies by repeat standard endoscopy can enhance the yield of intestinal metaplasia in patients with suspected short-segment Barrett esophagus. Costs of surveillance using standard endoscopy and random biopsies would be very high and using special techniques to target specific areas could ultimately help in cost reduction. Emerging data on new techniques and technology such as vital staining with methylene blue and protoporphyrin fluorescence can increase the yield of metaplasia and dysplasia. Biomarkers studies have revealed that p53 mutation by the loss of heterozygosity can help detect patients with low and high risk for cancer progression. Studies thus far have been unclear whether acid suppression alone can impact the malignant progression in Barrett esophagus patients. Inhibition of cyclooxygenase by aspirin or nonsteroidal anti-inflammatory drugs may be a promising chemoprevention strategy against dysplasia and esophageal adenocarcinoma development as shown in some recent studies. Nonsurgical treatment by photodynamic therapy or mucosal resection may be a less invasive and organ-sparing option for some patients with high-grade dysplasia and early adenocarcinoma.

SUMMARY

In the past year we have made major strides in our knowledge of this premalignant lesion. Recent studies have shed light in a better understanding of the epidemiology of Barrett esophagus, including clinical and endoscopic factors associated with high-grade dysplasia or esophageal adenocarcinoma and various biomarkers that would identify patient subsets with low and high risk for cancer progression. This will eventually have significant implications on the screening, surveillance, and treatment of the disease. Advanced endoscopic therapies including mucosectomy or photodynamic therapy may be emerging options in patients with intraepithelial neoplasia.

Barrett's esophagus and Barrett's carcinoma

The alarming rise in the incidence of esophageal adenocarcinomas in the Western world has focused interest on so-called Barrett's esophagus. Barrett's esophagus is characterized by specialized intestinal epithelium replacing the normal squamous epithelium in the distal esophagus and is considered a consequence of long-lasting and severe gastroesophageal reflux disease. A metaplasia-dysplasia-carcinoma sequence links Barrett's esophagus with adenocarcinoma of the distal esophagus (Barrett's cancer). Despite intensive research, many questions concerning the pathogenesis, diagnosis, and treatment of Barrett's esophagus and associated adenocarcinoma are still unanswered. Based on current data, the malignant progression of Barrett's esophagus cannot be substantially prevented by medical or surgical therapy for reflux. Although no firm data are available to show that surveillance strategies can reduce overall mortality from Barrett's cancer, early detection and cure are possible. Management of Barrett's esophagus and carcinoma is reviewed with reference to the sequence of disease from metaplasia to carcinoma.

The pathogenesis of Barrett's esophagus

Significant progress has been made in clinicians' understanding of the molecular pathogenesis of BE, and the laboratory findings are beginning to lead to hypothesis-driven clinical studies; however, the following questions remain unanswered: (1) how can clinicians identify the persons most at risk for the development of esophageal adenocarcinoma, (2) what are the environmental gene interactions in esophageal carcinogenesis, and (3) can clinicians prevent the development of esophageal adenocarcinoma in the population at risk? As esophageal adenocarcinoma starts to reach epidemic proportions, further research in these areas is urgently required. With the advent of the genomic era and an explosion in studies in BE, significant progress can be made.

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.