Risk of oesophageal cancer in Barrett's oesophagus and gastro-oesophageal reflux

Erosive reflux disease increases risk for esophageal adenocarcinoma, compared with nonerosive reflux

BACKGROUND & AIMS

Gastroesophageal reflux disease is a strong risk factor for esophageal adenocarcinoma, but it is not clear whether the mucosal inflammation that develops in patients with reflux disease promotes this cancer. We determined the development of adenocarcinoma among patients who underwent esophagogastroduodenoscopy and were found to have erosive (with esophagitis) or nonerosive (without esophagitis) reflux.

METHODS

We performed a nationwide cohort study using data from 33,849 patients with reflux disease (52% men; median age, 59.3 y) from population-based Danish medical registries, from 1996 through 2008. The observed incidences of adenocarcinoma were compared with the expected incidence for the general population, standardized by age, sex, and calendar time. Absolute risks were estimated using Kaplan-Meier methods.

RESULTS

In the study cohort, 26,194 of the patients (77%) had erosive reflux disease and 37 subsequently developed esophageal adenocarcinoma after a mean follow-up time of 7.4 years. Their absolute risk after 10 years was 0.24% (95% confidence interval [CI], 0.15%-0.32%). The incidence of cancer among patients with erosive reflux disease was significantly greater than that expected for the general population (standardized incidence ratio, 2.2; 95% CI, 1.6-3.0). In contrast, of the 7655 patients with nonerosive reflux disease, only 1 was diagnosed with esophageal adenocarcinoma after 4.5 years of follow-up evaluation (standardized incidence ratio, 0.3; 95% CI, 0.01-1.5).

CONCLUSIONS

Erosive reflux disease, but not nonerosive disease, increased the risk of esophageal adenocarcinoma, based on analysis of population-based Danish medical registries. Inflammation therefore might be an important factor in the progression from reflux to esophageal adenocarcinoma.

The effect of alginates on deoxycholic-acid-induced changes in oesophageal mucosal biology at pH 4

Long-standing gastro-oesophageal reflux disease (GORD) can give rise to Barrett's oesophagus (BM), a metaplastic condition and precursor to oesophageal adenocarcinoma (AC). Oesophageal cancer was once rare but is now the 5th biggest cancer killer in the U.K. Reflux of bile acids into the oesophagus is implicated in the progression to BM as bile acids at pH 4 have been shown to induce c-myc expression, an oncogene upregulated in BM and AC. In the present study we investigated the role of the biopolymer alginate on bile acid induced molecular changes in oesophageal cell lines. OE21, OE33 and TE-7 oesophageal cell lines were exposed to 100 microM deoxycholic acid at pH 4 in the presence or absence of alginates. Levels of c-myc, E-cadherin, beta-catenin and Tcf signalling were determined by Real-Time PCR, Western blotting, immunofluoresence and reporter assays. All alginates tested were able to prevent the induction of c-myc by acidified deoxycholic acid in vitro. The upstream effects of acidified deoxycholic acid on E-cadherin, beta-catenin and Tcf signalling were also suppressed by alginate. Therefore, we have demonstrated that reflux of bile acids into the oesophagus initiates a potentially damaging molecular cascade of events using an in vitro model and that a biopolymer, alginate, can protect against these effects.

Cigarette smoking increases risk of Barrett's esophagus: an analysis of the Barrett's and Esophageal Adenocarcinoma Consortium

BACKGROUND & AIMS

Cigarette smoking has been implicated in the etiology of esophageal adenocarcinoma, but it is not clear if smoking is a risk factor for Barrett's esophagus. We investigated whether tobacco smoking and other factors increase risk for Barrett's esophagus.

METHODS

We analyzed data from 5 case-control studies included in the international Barrett's and Esophageal Adenocarcinoma Consortium. We compared data from subjects with Barrett's esophagus (n = 1059) with those from subjects with gastroesophageal reflux disease (gastroesophageal reflux disease controls, n = 1332), and population-based controls (n = 1143), using multivariable logistic regression models to test associations with cigarette smoking. We also tested whether cigarette smoking has synergistic effects with other exposures, which might further increase risk for Barrett's esophagus.

RESULTS

Subjects with Barrett's esophagus were significantly more likely to have ever smoked cigarettes than the population-based controls (odds ratio [OR] = 1.67; 95% confidence interval [CI]: 1.04-2.67) or gastroesophageal reflux disease controls (OR = 1.61; 95% CI: 1.33-1.96). Increasing pack-years of smoking increased the risk for Barrett's esophagus. There was evidence of a synergy between ever-smoking and heartburn or regurgitation; the attributable proportion of disease among individuals who ever smoked and had heartburn or regurgitation was estimated to be 0.39 (95% CI: 0.25-0.52).

CONCLUSIONS

Cigarette smoking is a risk factor for Barrett's esophagus. The association was strengthened with increased exposure to smoking until ∼20 pack-years, when it began to plateau. Smoking has synergistic effects with heartburn or regurgitation, indicating that there are various pathways by which tobacco smoking might contribute to development of Barrett's esophagus.

Submucosal glands in the columnar-lined oesophagus: evidence of an association with metaplasia and neosquamous epithelium

AIM

A multipotential stem cell, possibly located in the submucosal gland ducts, has been suggested as the origin of metaplastic mucosa in the oesophagus. The topographic distribution of these glands and their excretory ducts (SMG) within the columnar lined oesophagus (CLO) is largely unknown. The aim of this study was to examine the distribution of SMG in relation to the type of overlying epithelium in patients with CLO.

METHODS AND RESULTS

Seven oesophageal resection specimens were examined histologically in toto. The median frequency of SMG was similar in the metaplastic segments (0.12 SMG/mm) and the normal squamous segments (0.10 SMG/mm). Within the metaplastic segments, the median frequency of SMG beneath the squamous islands was significantly higher than that observed under the columnar lined parts (0.22 versus 0.08 SMG/mm, P = 0.046), There was a strong accumulation of SMG at the squamo-columnar transition zones (0.53 SMG/mm), which was significantly greater than that found in the columnar and squamous parts (P = 0.001 and 0.002, respectively).

CONCLUSIONS

The relative accumulation of SMG beneath squamous islands and the squamo-columnar junctions within the metaplastic segment supports the hypothesis that both metaplastic columnar mucosa and neosquamous epithelium originate from a progenitor in the SMG.

Barrett's Esophagus: A Review of Biology and Therapeutic Approaches

Despite advances in diagnosis and therapy, esophageal cancer remains a highly lethal disease. The incidence of esophageal adenocarcinoma (EAC) has risen faster than that of any other cancer in the western world, and Barrett's esophagus (BE) may be a significant contributing factor. In-depth knowledge of biology of cancer progression and cancer could lead to the identification of biomarkers that are the hallmark of BE's progression. By integrating validated biomarkers of progression into clinical practice, there is a possibility of identifying high-risk patient population for targeted surveillance, and such biomarkers may serve as novel therapeutic targets for chemoprevention and therapy. Clinical management of BE has improved considerably due to the improvements in endoscopic resection and ablation techniques. We discuss the current status of biology and therapeutic approaches to BE.

Validation of the Prague C & M criteria for the endoscopic grading of Barrett's esophagus by gastroenterology trainees: a multicenter study

BACKGROUND

The Prague C & M criteria, developed for the endoscopic grading of Barrett's esophagus (BE), (C = circumferential length, M = maximal length) were previously validated among a panel of 29 expert endoscopists with a special interest in BE. Its performance among gastroenterology trainees is unknown.

OBJECTIVE

To test interobserver agreement among gastroenterology trainees for the Prague C & M criteria, identification of the gastroesophageal junction (GEJ) and the diaphragmatic hiatus.

DESIGN

A prospective study.

SETTING

Two tertiary referral centers.

PATIENTS AND INTERVENTIONS

Standardized endoscopic videos were used.

MAIN OUTCOME MEASUREMENTS

Interobserver agreement.

RESULTS

Eighteen high-quality videos (normal esophagus, short and long lengths of BE, equally distributed) were independently evaluated by 18 gastroenterology trainees (year 1, n = 5; year 2, n = 6; year 3, n = 7) after administration of a formal teaching module by an expert endoscopist. Overall intraclass correlation coefficients for assessment of the C and M extent of the endoscopic BE segment above the GEJ were 0.94 (95% CI, 0.89-0.98) and 0.96 (95% CI, 0.94-0.98), respectively. The overall intraclass correlation coefficients for GEJ and diaphragmatic hiatus location recognition were 0.92 (0.86-0.96) and 0.90 (0.82-0.95), respectively. The year of training did not affect interobserver agreement.

LIMITATIONS

The use of videos for endoscopic evaluation.

CONCLUSION

After standardized teaching, the Prague C & M criteria have high overall validity among gastroenterology trainees irrespective of the level of training for endoscopic evaluation of visualized BE lengths as well as key endoscopic landmarks.

Role of the insulin-like growth factor 1 axis and visceral adiposity in oesophageal adenocarcinoma

BACKGROUND

Epidemiological studies have linked obesity with many cancers. The insulin-like growth factor (IGF) 1 axis may be an important mediator in obesity-associated cancer. This study examined the relationship between IGF-1 and its receptor (IGF-1R) in oesophageal adenocarcinoma, a cancer strongly linked to obesity.

METHODS

Patients with oesophageal adenocarcinoma considered suitable for attempted curative treatment were studied. Visceral adiposity was defined by waist circumference or visceral fat area. Free and total IGF-1 in serum were measured by enzyme-linked immunosorbent assay. Quantitative polymerase chain resection was used to determine mRNA expression of IGF-1 and IGF-1R in resected tumour samples. IGF-1R expression in tissue microarrays (TMAs) was quantified by immunohistochemistry.

RESULTS

A total of 220 patients were studied. Total and free IGF-1 levels were significantly increased in the serum of viscerally obese patients. Gene expression analysis revealed a significant association between obesity status and both IGF-1R (P = 0·021) and IGF-1 (P = 0·031) in tumours. TMA analysis demonstrated that IGF-1R expression in resected tumours was significantly higher in viscerally obese patients than in those of normal weight (P = 0·023). Disease-specific survival was longer in patients with negative IGF-1R expression than in those with IGF-1R-positive tumours (median 60·0 versus 23·4 months; P = 0·027).

CONCLUSION

This study highlighted the association of the IGF axis with visceral obesity, and a potential impact on the biology of oesophageal adenocarcinoma through its receptor. Targeting the IGF axis may have a rationale in future studies.

Erosive esophagitis is a risk factor for Barrett's esophagus: a community-based endoscopic follow-up study

OBJECTIVES

Symptomatic gastroesophageal reflux disease (GERD) is associated with a significantly increased risk of esophageal adenocarcinoma, but its natural history in the general population is poorly understood. Whether nonerosive reflux disease (NERD) is a risk factor for Barrett's esophagus (BE), the precursor of esophageal adenocarcinoma, is unknown. Furthermore, quantifying the risk of incident BE in those with untreated reflux esophagitis has not been possible. We aimed, in a prospective follow-up study with endoscopy, to evaluate the risk of BE in a cohort from the Swedish general population (the Kalixanda Study).

METHODS

Those with endoscopic or histological findings suggestive of GERD and randomly half of those with NERD (n=481) were invited for follow-up investigation including endoscopy and a validated symptom questionnaire 5 years after the initial study. Multinomial logistic regression was used to estimate relative risk ratios (RRRs) and 95% confidence intervals (CIs) for change in presentation of GERD.

RESULTS

Of the 405 subjects available for inclusion, endoscopy was performed in 284 (response rate 70.1%). The incidence of BE was 9.9/1,000 person-years. Of those with NERD at baseline (n=113), progression to erosive esophagitis was found in 11; 2 developed BE. Erosive esophagitis (n=90) progressed to a more severe grade in 12 and to BE in 8 cases. Erosive esophagitis at baseline was independently associated with BE at follow-up (RRR 5.2; 95% CI 1.2-22.9).

CONCLUSIONS

Compared with being free of GERD at follow-up, erosive esophagitis is a major risk factor for BE (with a fivefold increased risk) after 5 years in the general population.

Incidence of adenocarcinoma among patients with Barrett's esophagus

BACKGROUND

Accurate population-based data are needed on the incidence of esophageal adenocarcinoma and high-grade dysplasia among patients with Barrett's esophagus.

METHODS

We conducted a nationwide, population-based, cohort study involving all patients with Barrett's esophagus in Denmark during the period from 1992 through 2009, using data from the Danish Pathology Registry and the Danish Cancer Registry. We determined the incidence rates (numbers of cases per 1000 person-years) of adenocarcinoma and high-grade dysplasia. As a measure of relative risk, standardized incidence ratios were calculated with the use of national cancer rates in Denmark during the study period.

RESULTS

We identified 11,028 patients with Barrett's esophagus and analyzed their data for a median of 5.2 years. Within the first year after the index endoscopy, 131 new cases of adenocarcinoma were diagnosed. During subsequent years, 66 new adenocarcinomas were detected, yielding an incidence rate for adenocarcinoma of 1.2 cases per 1000 person-years (95% confidence interval [CI], 0.9 to 1.5). As compared with the risk in the general population, the relative risk of adenocarcinoma among patients with Barrett's esophagus was 11.3 (95% CI, 8.8 to 14.4). The annual risk of esophageal adenocarcinoma was 0.12% (95% CI, 0.09 to 0.15). Detection of low-grade dysplasia on the index endoscopy was associated with an incidence rate for adenocarcinoma of 5.1 cases per 1000 person-years. In contrast, the incidence rate among patients without dysplasia was 1.0 case per 1000 person-years. Risk estimates for patients with high-grade dysplasia were slightly higher.

CONCLUSIONS

Barrett's esophagus is a strong risk factor for esophageal adenocarcinoma, but the absolute annual risk, 0.12%, is much lower than the assumed risk of 0.5%, which is the basis for current surveillance guidelines. Data from the current study call into question the rationale for ongoing surveillance in patients who have Barrett's esophagus without dysplasia. (Funded by the Clinical Institute, University of Aarhus, Aarhus, Denmark.).

Total cancer incidence and overall mortality are not increased among patients with Barrett's esophagus

BACKGROUND & AIMS

Barrett's esophagus (BE) increases risk for esophageal adenocarcinoma, but it is not clear how it affects risk for other cancers or overall mortality. We analyzed data from a population-based cohort of subjects with BE.

METHODS

The Netherlands Cohort Study was initiated in 1986 and included 120,852 participants (55-69 years old at baseline). Until December 2002, 626 incident cases of BE (excluding nonintestinal metaplasia) were identified by record linkage with the nationwide Pathology Registry. This cohort was followed for a median period of 5.7 years; data on cancer and mortality were obtained from record linkage to the Netherlands Cancer Registry and Statistics Netherlands. The expected number of cases was calculated using national cancer incidence and mortality data.

RESULTS

In the BE cohort, 13 individuals developed esophageal cancer and 5 developed gastric cancer. The ratio of observed:expected (O:E) incidence of esophageal and gastric cancer was 10.0 (95% confidence interval [CI], 5.3-17.1) and 1.8 (95% CI, 0.6-4.2), respectively. Total cancer incidence (excluding esophageal and gastric cancer) increased in the BE cohort, although not by a statistically significant amount (O:E, 1.3; 95% CI, 1.0-1.6). Of cancer subtypes, incidences of small intestinal and pancreatic cancer increased in subjects with BE, but not by a statistically significant amount, after exclusion of data from the first 6 months of follow-up. During the follow-up period, 225 individuals with BE died. Mortality from all causes (excluding esophageal and gastric cancer) was not increased among subjects with BE (O:E, 1.0; 95% CI, 0.9-1.2), nor was mortality from specific causes of death.

CONCLUSIONS

The incidence of esophageal cancer was increased in a population-based cohort of subjects with BE. However, when esophageal and gastric cancers were excluded, total cancer incidence and overall mortality were not increased among subjects with BE.

Whole genome expression array profiling highlights differences in mucosal defense genes in Barrett's esophagus and esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) has become a major concern in Western countries due to rapid rises in incidence coupled with very poor survival rates. One of the key risk factors for the development of this cancer is the presence of Barrett's esophagus (BE), which is believed to form in response to repeated gastro-esophageal reflux. In this study we performed comparative, genome-wide expression profiling (using Illumina whole-genome Beadarrays) on total RNA extracted from esophageal biopsy tissues from individuals with EAC, BE (in the absence of EAC) and those with normal squamous epithelium. We combined these data with publically accessible raw data from three similar studies to investigate key gene and ontology differences between these three tissue states. The results support the deduction that BE is a tissue with enhanced glycoprotein synthesis machinery (DPP4, ATP2A3, AGR2) designed to provide strong mucosal defenses aimed at resisting gastro-esophageal reflux. EAC exhibits the enhanced extracellular matrix remodeling (collagens, IGFBP7, PLAU) effects expected in an aggressive form of cancer, as well as evidence of reduced expression of genes associated with mucosal (MUC6, CA2, TFF1) and xenobiotic (AKR1C2, AKR1B10) defenses. When our results are compared to previous whole-genome expression profiling studies keratin, mucin, annexin and trefoil factor gene groups are the most frequently represented differentially expressed gene families. Eleven genes identified here are also represented in at least 3 other profiling studies. We used these genes to discriminate between squamous epithelium, BE and EAC within the two largest cohorts using a support vector machine leave one out cross validation (LOOCV) analysis. While this method was satisfactory for discriminating squamous epithelium and BE, it demonstrates the need for more detailed investigations into profiling changes between BE and EAC.

Early G₁ cyclin-dependent kinases as prognostic markers and potential therapeutic targets in esophageal adenocarcinoma

PURPOSE

Chromosomal gain at 7q21 is a frequent event in esophageal adenocarcinoma (EAC). However, this event has not been mapped with fine resolution in a large EAC cohort, and its association with clinical endpoints and functional relevance are unclear.

EXPERIMENTAL DESIGN

We used a cohort of 116 patients to fine map the 7q21 amplification using SNP microarrays. Prognostic significance and functional role of 7q21 amplification and its gene expression were explored.

RESULTS

Amplification of the 7q21 region was observed in 35% of tumors with a focal, minimal amplicon containing six genes. 7q21 amplification was associated with poor survival and analysis of gene expression identified cyclin-dependent kinase 6 (CDK6) as the only gene in the minimal amplicon whose expression was also associated with poor survival. A low-level amplification (10%) was observed at the 12q13 region containing the CDK6 homologue cyclin-dependent kinase 4 (CDK4). Both amplification and expression of CDK4 correlated with poor survival. A combined model of both CDK6 and CDK4 expressions is a superior predictor of survival than either alone. Specific knockdown of CDK4 and/or CDK6 by siRNAs shows that they are required for proliferation of EAC cells and that their function is additive. PD-0332991 targets the kinase activity of both molecules and suppresses proliferation and anchorage independence of EAC cells through activation of the pRB pathway.

CONCLUSIONS

We suggest that CDK6 is the driver of 7q21 amplification and that both CDK4 and CDK6 are prognostic markers and bona fide oncogenes in EAC. Targeting these molecules may constitute a viable new therapy for this disease.

Targeting key signalling pathways in oesophageal adenocarcinoma: A reality for personalised medicine?

Cancer treatments are rapidly changing. Curative treatment for oesophageal adenocarcinoma currently involves surgery and cytotoxic chemotherapy or chemoradiotherapy. Outcomes for both regimes are generally poor as a result of tumor recurrence. We have reviewed the key signalling pathways associated with oesophageal adenocarcinomas and discussed the recent trials of novel agents that attempt to target these pathways. There are many trials underway with the aim of improving survival in oesophageal cancer. Currently, phase 2 and 3 trials are focused on MAP kinase inhibition, either through inhibition of growth factor receptors or signal transducer proteins. In order to avoid tumor resistance, it appears to be clear that targeted therapy will be needed to combat the multiple signalling pathways that are in operation in oesophageal adenocarcinomas. This may be achievable in the future with the advent of gene signatures and a combinatorial approach.

From GERD to Barrett's esophagus: is the pattern in Asia mirroring that in the West?

Gastroesophageal reflux disease (GERD) is a known predisposing factor for Barrett's esophagus. Amongst individuals with symptomatic GERD, the prevalence of Barrett esophagus is estimated to be more than 10%, and an individual with Barrett's esophagus is more likely than the general population to develop esophageal adenocarcinoma. In Western Europe and North America, incidence of esophageal adenocarcinoma had been on the upward trend for many decades. In comparison, although the prevalence of GERD and reflux esophagitis has increased several fold in some parts of Asia, the prevalence of esophageal adenocarcinoma and Barrett's esophagus remains generally low in the region. Rising incidence of esophageal adenocarcinoma has been observed in regions witnessing increasing prevalence of GERD. If the recent increase in prevalence of GERD in parts of urbanized Asia is any indication of the beginning of an upsurge in the incidence of Barrett's esophagus and associated adenocarcinoma, would we be witnessing a pattern of epidemiological shift mirroring that in the West? Given that more than 90% of Barrett's esophagus in Asian patients is of the short-segment type, which is reported to have lesser propensity to develop to adenocarcinoma, could the ongoing epidemiologic transition take Asia on the same trail as that which the West has taken? This article will draw on relevant findings from various parts of Asia and take an in-depth look at prevailing disease trends to see where Asia stands now in the changing epidemiology of GERD, Barrett's esophagus and associated adenocarcinoma.

Development and maintenance of cancer stem cells under chronic inflammation

In many human cancers, tumorigenic potential is not equally shared by all cells but is restricted to phenotypically distinct subpopulations termed cancer stem cells. Cancer stem cells are also capable of both self-renewal and differentiation, and these functional properties have been suggested to play major roles in tumor initiation and progression. The factors responsible for the development of cancer stem cells and their subsequent regulation are unclear, but several chronic inflammatory states have been associated with an increased risk of malignancy. Therefore, it is possible that specific processes associated with chronic inflammation, as well as the adaptation to cellular stress, regulate cancer stem cells. Several factors associated with chronic inflammation, including cytokines, oxidative stress, and hypoxia, induce the activation of specific cellular response programs that can affect the survival, proliferation, metabolism, and differentiation of cancer cells, as well as the self-renewal and quiescence of normal stem cells. In this review, we discuss how these adaptive processes potentially become subverted to enhance the development and function of cancer stem cells.

The ERK MAP kinase-PEA3/ETV4-MMP-1 axis is operative in oesophageal adenocarcinoma

BACKGROUND

Many members of the ETS-domain transcription factor family are important drivers of tumourigenesis. In this context, their activation by Ras-ERK pathway signaling is particularly relevant to the tumourigenic properties of many ETS-domain transcription factors. The PEA3 subfamily of ETS-domain transcription factors have been implicated in tumour metastasis in several different cancers.

RESULTS

Here, we have studied the expression of the PEA3 subfamily members PEA3/ETV4 and ER81/ETV1 in oesophageal adenocarcinomas and determined their role in oesophageal adenocarcinoma cell function. PEA3 plays an important role in controlling both the proliferation and invasive properties of OE33 oesophageal adenocarcinoma cells. A key target gene is MMP-1. The ERK MAP kinase pathway activates PEA3 subfamily members and also plays a role in these PEA3 controlled events, establishing the ERK-PEA3-MMP-1 axis as important in OE33 cells. PEA3 subfamily members are upregulated in human adenocarcinomas and expression correlates with MMP-1 expression and late stage metastatic disease. Enhanced ERK signaling is also more prevalent in late stage oesophageal adenocarcinomas.

CONCLUSIONS

This study shows that the ERK-PEA3-MMP-1 axis is upregulated in oesophageal adenocarcinoma cells and is a potentially important driver of the metastatic progression of oesophageal adenocarcinomas.

Exogenous luminal nitric oxide exposure accelerates columnar transformation of rat esophagus

Exposure of the esophageal mucosa to refluxed gastroduodenal contents is recognized to be an important risk factor for Barrett's esophagus (BE). At the human gastroesophageal junction, nitric oxide is generated luminally through the enterosalivary recirculation of dietary nitrate, and in cases with gastroesophageal reflux, the site of luminal nitric oxide generation could shift to the distal esophagus. The aim of this study is to investigate whether exogenous luminal nitric oxide could promote the development of BE in rats. Sodium nitrite plus ascorbic acid were administered to a rat surgical model of BE, in which the gastroduodenal contents were refluxed into the esophagus to generate exogenous luminal nitric oxide in the esophagus by the acid-catalyzed chemical reaction between the 2 reagents. The emergence of BE was evaluated histologically in the early phase (several weeks) after the surgery with or without exogenous nitric oxide administration. To elucidate the histogenesis of BE, CDX2, MUC2 and MUC6 expressions were investigated immunohistochemically. Coadministration of sodium nitrite plus ascorbic acid significantly accelerated the timing of emergence and increased the area of BE compared with controls. Administration of either reagent alone did not show any promotive effects on BE formation. Immunohistochemically, the columnar epithelium thus induced was similar to the specialized intestinal metaplasia in human BE. The results of this animal model study suggest that exogenous luminal nitric oxide could be involved in the pathogenesis of the columnar transformation of the esophagus. Further studies in human are warranted.

Affinity peptide for targeted detection of dysplasia in Barrett's esophagus

BACKGROUND & AIMS

Dysplasia is a premalignant condition in Barrett's esophagus that is difficult to detect on endoscopy because of its flat architecture and patchy distribution. Peptides are promising for use as novel molecular probes that identify cell surface targets unique to disease and can be fluorescence-labeled for detection. We aim to select and validate an affinity peptide that binds to esophageal dysplasia for future clinical studies.

METHODS

Peptide selection was performed using phage display by removing nonspecific binders using Q-hTERT (intestinal metaplasia) cells and achieving specific binding against OE33 (esophageal adenocarcinoma) cells. Selective binding was confirmed on bound phage counts, enzyme-linked immunosorbent assay (ELISA), flow cytometry, competitive inhibition, and fluorescence microscopy. On stereomicroscopy, specific peptide binding to dysplasia on endoscopically resected specimens was assessed by rigorous registration of fluorescence intensity to histology in 1-mm intervals.

RESULTS

The peptide sequence SNFYMPL was selected and showed preferential binding to target cells. Reduced binding was observed on competition with unlabeled peptide in a dose-dependent manner, an affinity of K(d) = 164 nmol/L was measured, and peptide binding to the surface of OE33 cells was validated on fluorescence microscopy. On esophageal specimens (n = 12), the fluorescence intensity (mean ± SEM) in 1-mm intervals classified histologically as squamous (n = 145), intestinal metaplasia (n = 83), dysplasia (n = 61), and gastric mucosa (n = 69) was 46.5 ± 1.6, 62.3 ± 5.8, 100.0 ± 9.0, and 42.4 ± 3.0 arb units, respectively.

CONCLUSIONS

The peptide sequence SNFYMPL binds specifically to dysplasia in Barrett's esophagus and can be fluorescence labeled to target premalignant mucosa on imaging.

Reproductive and sex hormonal factors and oesophageal and gastric junction adenocarcinoma: a pooled analysis

BACKGROUND

The rapidly rising incidence and the striking male predominance are as yet unexplained features of oesophageal and gastric junction adenocarcinoma. Few and underpowered studies have examined the impact of female reproductive factors on risk of these adenocarcinomas in women. We therefore pooled data on women from four population-based case-control studies to examine the association of female reproductive and sex hormonal factors with oesophageal and gastric junction adenocarcinoma.

METHODS

Data on women from case-control studies conducted in Ireland, the United Kingdom (UK), Australia and United States of America (USA) were pooled. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for a range of reproductive factors, adjusted for age, study and major risk factors for oesophageal and gastric junction adenocarcinoma.

RESULTS

We included 218 cases and 862 controls. Among parous women, a reduced risk of oesophageal and gastric junction adenocarcinoma was found after breastfeeding (OR=0.58, 95% CI=0.37-0.92) and the risk decreased with increased duration of breastfeeding (>12 months OR=0.42, 95% CI=0.23-0.77). The endogenous reproductive factors such as parity, menstruation, history of pregnancy and the exogenous factors such as use of oral contraceptives and of hormone replacement therapy were not statistically significantly associated with oesophageal and gastric junction adenocarcinoma.

CONCLUSION

Our findings suggest that breastfeeding is associated with a decreased risk of oesophageal and gastric junction adenocarcinoma. The potential mechanism of this association warrants further investigation.

The changing face of esophageal cancer

The two main histological esophageal cancer types, adenocarcinoma and squamous cell carcinoma, differ in incidence, geographic distribution, ethnic pattern and etiology. This article focuses on epidemiology with particular reference to geographic and temporal variations in incidence, along with a review of the evidence supporting environmental and genetic factors involved in esophageal carcinogenesis. Squamous cell carcinoma of the esophagus remains predominantly a disease of the developing world. In contrast, esophageal adenocarcinoma is mainly a disease of western developed societies, associated with obesity and gastro-esophageal reflux disease. There has been a dramatic increase in the incidence of adenocarcinoma in developed countries in parallel with migration of both esophageal and gastric adenocarcinomas towards the gastro-esophageal junction.

Obesity and gastrointestinal cancer

BACKGROUND

There is emerging evidence of a strong association between obesity and gastrointestinal cancer. This review summarizes the evidence from an epidemiological and pathophysiological perspective.

METHODS

Relevant medical literature was identified from searches of PubMed and references cited in appropriate articles were identified. Selection of articles was based on peer review, journal and relevance.

RESULTS

Numerous epidemiological studies consistently identified an increased risk of developing oesophageal adenocarcinoma and colorectal carcinoma in the obese. The association between obesity and other gastrointestinal malignancies was less robust. Sex seems important with respect to cancer risk. Adipose tissue, particularly viscerally located fat, is metabolically active and exerts systemic endocrine effects. Putative pathophysiological mechanisms linking obesity and carcinogenesis include the insulin-like growth factor axis, adipocytokines and sex steroids.

CONCLUSION

A better understanding of the mechanisms that link obesity and cancer may uncover targets for intervention. Tackling obesity may result in a reduction in the incidence in addition to mortality of certain cancers in future.

Immunohistochemical overexpression of the p53 protein and Ki-67 (MIB-1) antigen in patients with GERD and chronic esophagitis

BACKGROUND AND STUDY AIMS

Patients with gastroesophageal reflux disease and Barrett esophagus have an increased risk of developing adenocarcinoma of the esophagus. It is uncertain whether molecular or proliferative alterations are present in the early stages of disease.

METHODS

One hundred thirty-eight patients with gastroesophageal reflux disease symptoms were subjected to upper gastrointestinal endoscopy with biopsies of the esophageal mucosa. p53 protein expression and the Ki-67 proliferation index were determined by immunohistochemical studies. Patients were divided into 4 groups according to histopathologic diagnosis: G1, normal epithelium (n=58); G2, mild esophagitis (n=42); G3, moderate esophagitis (n=23), and G4, severe esophagitis (n=15).

RESULTS

p53 overexpression was detected in 7% of G1, 21.4% of G2, 52.2% of G3, and 60% of G4 patients. There were significant differences between G1 and G3 or G4 (P<0.001) and between G2 and G4 (P<0.05). The Ki-67 index was 21.3+/-19.5% in G1, 30.8+/-23.4% in G2, 47.1+/-23.2% in G3, and 48.3+/-25.7% in G4. Significant differences in the Ki-67 index were found between groups: G1 x G3 (P<0.001), G1 x G4 (P<0.001), G2 x G3 (P=0.026), and G2 x G4 (P=0.046). p53 and Ki-67 overexpression were correlated with the severity of esophagitis (P<0.001).

CONCLUSIONS

p53 overexpression and the Ki-67 (MIB-1) index were correlated with histologic findings of inflammation in the esophageal mucosa, particularly in the moderate and severe forms of chronic esophagitis.

Induction of epigenetic alterations by chronic inflammation and its significance on carcinogenesis

Chronic inflammation is deeply involved in development of human cancers, such as gastric and liver cancers. Induction of cell proliferation, production of reactive oxygen species, and direct stimulation of epithelial cells by inflammation-inducing factors have been considered as mechanisms involved. Inflammation-related cancers are known for their multiple occurrences, and aberrant DNA methylation is known to be present even in noncancerous tissues. Importantly, for some cancers, the degree of accumulation has been demonstrated to be correlated with risk of developing cancers. This indicates that inflammation induces aberrant epigenetic alterations in a tissue early in the process of carcinogenesis, and accumulation of such alterations forms "an epigenetic field for cancerization." This also suggests that inhibition of induction of epigenetic alterations and removal of the accumulated alterations are novel approaches to cancer prevention. Disturbances in cytokine and chemokine signals and induction of cell proliferations are important mechanisms of how inflammation induces aberrant DNA methylation. Aberrant DNA methylation is induced in specific genes, and gene expression levels, the presence of RNA polymerase II (active or stalled), and trimethylation of H3K4 are involved in the specificity. Expression of DNA methyltransferases (DNMTs) is not necessarily induced by inflammation, and local imbalance between DNMTs and factors that protect genes from DNA methylation seems to be important.

Inflammation and cancer: interweaving microRNA, free radical, cytokine and p53 pathways

Chronic inflammation and infection are major causes of cancer. There are continued improvements to our understanding of the molecular connections between inflammation and cancer. Key mediators of inflammation-induced cancer include nuclear factor kappa B, reactive oxygen and nitrogen species, inflammatory cytokines, prostaglandins and specific microRNAs. The collective activity of these mediators is largely responsible for either a pro-tumorigenic or anti-tumorigenic inflammatory response through changes in cell proliferation, cell death, cellular senescence, DNA mutation rates, DNA methylation and angiogenesis. As our understanding grows, inflammatory mediators will provide opportunities to develop novel diagnostic and therapeutic strategies. In this review, we provide a general overview of the connection between inflammation, microRNAs and cancer and highlight how our improved understanding of these connections may provide novel preventive, diagnostic and therapeutic strategies to reduce the health burden of cancer.

[Diagnostic and interventional endoscopy in gastroenterology : from high-resolution chips and procedures for endoscopic resection to NOTES]

In the past 10 years endoscopic diagnostics has benefited from technologies such as big chips, high-definition television (HDTV) and narrow band imaging (NBI). Video capsule endoscopy and double balloon enteroscopy have facilitated visualization of the entire small bowel. A number of studies on mucosal Barrett's and gastric cancers could prove that endoscopic mucosal resection (EMR) is oncologically equivalent to surgical resection when certain criteria are respected. However, EMR is less invasive and carries a substantially lower complication risk and mortality compared to surgery. Endoscopic submucosal dissection (ESD) facilitates en bloc resection with thorough histopathologic evaluation of the specimen, e.g. for mucosal lesions in the stomach and rectum. Endosonography (EUS) guided transgastric necrosectomy using a flexible gastroscope has set a milestone in the treatment of infected pancreatic necroses and has replaced open surgery in many centers. Natural orifice transluminal endoscopic surgery (NOTES) uses natural body openings as minimally invasive access to the abdomen and mediastinum. Interventional GI endoscopists and minimally invasive surgeons have profited from these innovations in micromechanics and microelectronics.

Role of obesity in Barrett's esophagus and cancer

The incidence of esophageal adenocarcinoma (EAC) has increased dramatically in the western world, and there also appears to have been an increase in the incidence of Barrett's esophagus and gastroesophageal reflux disease in recent years. The contemporaneous increase in obesity has focused interest on whether obesity is a risk factor for EAC and its precursors. This article reviews current evidence for the role that overweight/obesity and body fat distribution have in development of the esophagitis metaplasia-dysplasia-adenocarcinoma sequence. Particular attention is paid to the stage at which adiposity may act to influence the risk of EAC, because this determines the importance of weight control and weight loss at each stage in the disease spectrum for the prevention of EAC.

Risk factors for esophageal cancer development

The incidence of esophageal adenocarcinoma is increasing at a rate greater than that of any other cancer in the Western world today. Barrett's esophagus is a clearly recognized risk factor for the development of esophageal adenocarcinoma, but the overwhelming majority of patients with Barrett's esophagus will never develop esophageal cancer. To date, dysplasia remains the only factor useful for identifying patients at increased risk for the development of esophageal adenocarcinoma in clinical practice. Other epidemiologic risk factors include aging, gender, race, obesity, reflux symptoms, smoking, and diet. Factors that may protect against the development of adenocarcinoma include infection with Helicobacter pylori, a diet rich in fruits and vegetables, and consumption of aspirin and NSAIDs.

Surgical palliation for Barrett's esophagus cancer

Adenocarcinoma arising in the setting of Barrett's esophagus has the fastest increasing incidence of any malignancy in the United States. Advanced esophageal cancer carries an overall poor prognosis with most patients presenting with incurable disease. Over the past several years, new options have been introduced for the purpose of providing palliative therapy to improve quality of life. Stent placement is the most widely used palliative therapy and rapidly relieves dysphagia; however, distal migration continues to be a disadvantage. Laser therapy and brachytherapy are also administered but require repeated treatment sessions. Future options for providing effective therapy for endstage disease include improved stent designs to decrease migration and multimodality methods that combine several options in one treatment session. This article focuses primarily on palliation of unresectable tumors of the esophagus and gastroesophageal junction.

Evidence-based radiation oncology: oesophagus

Oesophageal cancer remains to be a therapeutic and diagnostic challenge in multidisciplinary oncology. Radiotherapy is a crucial component of most curative and palliative approaches for oesophageal cancer. Aim of this educational review is to summarize the available evidence and to define the role of radiation-based treatment options for oesophageal cancer.

The Italian validation of the Montreal Global definition and classification of gastroesophageal reflux disease

BACKGROUND AND AIMS

Recently, a Global definition and a classification of gastroesophageal reflux disease (GERD) were developed by Montreal Consensus Group, composed of international expert gastroenterologists. Guidelines and consensus documents are, however, infrequently accepted and adopted at a local level. The aim of this study was to measure the acceptance of Montreal Global definition of GERD consensus document by specialists in a single country (Italy) and to measure the linguistic, scientific, and practical differences between the international consensus document and the Italian version.

METHODS

A 2-day meeting was held in June 2007 in Rome, Italy, attended by 147 Italian physicians who were experts in gastroenterology. They reviewed the individual original statements in their Italian translation and then voted on the statement using the scoring system used by the Montreal Consensus Group (6-point Likert scale). Voting was performed at baseline and after an analytical discussion on each statement, led by six internationally renowned experts. Consensus was defined as an agreement with a statement by at least two-thirds of the group. Results were compared with the Montreal statements.

RESULTS AND DISCUSSION

The level of consensus was already extremely high at the first vote (>90% with the two-thirds threshold). The level of agreement at the second vote increased slightly. The maximum variation between two votes was 33% (of increase from first to second round, 59-92%). The high level of agreement could be because of both the general acceptance of Montreal Consensus by scientific community, and the new scientific evidences published after the Montreal report, which fit with the original statements.

CONCLUSION

This study is the first national linguistic validation of the Montreal Global definition of GERD and is also proof of its scientific validity, based on the same methodology used to create the Montreal statements. It also suggests that evidence-based International disease classification systems can be applied to local settings after validation by local experts.

Effect of alpha-tocopherol, N-acetylcysteine and omeprazole on esophageal adenocarcinoma formation in a rat surgical model

We previously demonstrated that oxidative stress subsequent to gastroesophageal reflux is an important driving force of esophageal adenocarcinoma (EAC) formation in the esophagogastroduodenal anastomosis (EGDA) rat model. This study investigated the possible tumor inhibitory effects of 2 antioxidants, alpha-tocopherol (389 and 778 ppm), N-acetylcysteine (NAC, 500 and 1,000 ppm), and their combination (389 and 500 ppm, respectively), as well as an antacid therapeutic agent, omeprazole (1,400 ppm). The rats were fed experimental diets 2 weeks after EGDA. All the animals were sacrificed 40 weeks after EGDA and the esophagi were harvested for histopathological examination. alpha-Tocopherol dose-dependently decreased the incidence of EAC (p = 0.03), with 778 ppm alpha-tocopherol reducing the incidence of EAC to 59% (16/27) in comparison with 84% (26/31) in the control group (p = 0.04). Supplementation of alpha-tocopherol also increased the serum concentration of alpha-tocopherol. NAC at 500 and 1,000 ppm did not significantly decrease EAC incidence; however, the combination of alpha-tocopherol 389 ppm and NAC 500 ppm significantly reduced the incidence of EAC to 55% (15/27) (p = 0.02). alpha-Tocopherol alone or in combination with NAC significantly reduced the number of infiltrating cells positively stained for 4-hydroxynonenal. Omeprazole showed only a slight nonsignificant inhibitory effect at the dose given. Our results suggest that supplementation with alpha-tocopherol inhibits the development of EAC in the rat EGDA model and similar inhibitory effect can be achieved when a lower dose of alpha-tocopherol is used in combination with NAC.

Evaluation of risk factors and prevention strategies of esophageal cancer

Esophageal cancer is one of the most common fatal cancers worldwide. There are two major types of esophageal cancer, squamous cell carcinoma and adenocarcinoma. Because of the poor survival rate of esophageal cancer, successful assessment of risk factors and prevention strategies become crucial in prevention and treatment of this cancer. This article reviews the most updated research discoveries and reveals that tobacco, alcohol consumption and bad eating habits are considered as the major risk factors for esophageal cancer. Carcinogens-contaminated food, unbalanced diet, genetic susceptibility and some chronic gastrointestinal disease are also factors contributed to esophageal cancer development. To prevent this disease, there are two major strategies, primary and secondary preventions.

Systematic review: the epidemiology of gastro-oesophageal reflux disease in primary care, using the UK General Practice Research Database

BACKGROUND

Gastro-oesophageal reflux disease (GERD) is a common diagnosis in primary care; however, there has been no comprehensive review of the epidemiology of GERD in this setting.

AIM

To review systematically articles that used the General Practice Research Database to study the epidemiology of GERD.

METHODS

Systematic literature searches.

RESULTS

Seventeen articles fulfilled the inclusion criteria. The incidence of GERD in primary care was 4.5 new diagnoses per 1000 person-years in 1996 (95% CI: 4.4-4.7). A new diagnosis of GERD was associated with being overweight, obese or an ex-smoker. Prior diagnoses of ischaemic heart disease, peptic ulcer disease, nonspecific chest pain, nonspecific abdominal pain, chronic obstructive pulmonary disease and asthma were associated with a subsequent new GERD diagnosis. A first diagnosis of GERD was associated with an increased risk of a subsequent diagnosis of oesophageal adenocarcinoma, oesophageal stricture, chronic cough, sinusitis, chest pain, angina, gallbladder disease, irritable bowel syndrome or sleep problems. Mortality may be higher in patients with a GERD diagnosis than in those without in the first year after diagnosis, but not long term.

CONCLUSION

The General Practice Research Database is an effective way of studying the epidemiology of GERD in a large population-based primary care setting.

The definition and management of Barrett's oesophagus: a case report, review of the literature and a suggestion for the future

The definition of Barrett's oesophagus continues to evolve and there has been divergence in the diagnostic criteria internationally, which has implications for surveillance practices and research inclusion criteria. Here we describe the case of a 69-year-old female with 10 cm of gastric-type columnar-lined oesophagus confirmed on histochemical staining. Surveillance biopsies, performed according to protocol, revealed an intramucosal adenocarcinoma. The patient was successfully treated with a transhiatal oesophagectomy and a detailed examination of the entire surgical specimen confirmed that the columnar oesophagus was lined by gastric villiform mucosa complicated by intramucosal carcinoma, on the background of dysplasia with no intestinal metaplasia. This highlights the spectrum of metaplastic epithelia that can harbour malignant potential. There is a need for an international consensus on the classification of Barrett's oesophagus to aid research progress. Therefore, we propose a new classification for Barrett's oesophagus based on a combination of endoscopic and histopathological features.

Endoscopic evaluation of esophago-gastro-jejunostomy in rat model of Barrett's esophagus

Endoscopy can be used to monitor the onset of metaplastic transformation and to observe the progression of neoplasia in small animal models of Barrett's esophagus. By avoiding animal sacrifice, the natural history of this disease can be studied in a longitudinal fashion. We aim to characterize the endoscopic features of esophageal mucosa at various stages of the metaplasia-dysplasia-carcinoma sequence in a rat reflux model of Barrett's for comparison with histology. Acid and bile reflux was produced by introducing a side-to-side esophago-gastro-jejunostomy in Sprague-Dawley rats. Endoscopic examination of the distal esophagus was performed in 24 surgically altered and 4 control rats, between weeks 24 and 36 after the operation in 4-week intervals, and all rats were biopsied and sacrificed at 36 weeks. Endoscopic images were classified based on the surface mucosal patterns of the distal esophagus and then compared with histology. The endoscopic appearance was classified as: (i) normal, characterized by a smooth surface; (ii) intestinal metaplasia, defined as elevated plaques/ridges, deep grooves, and thin linear folds; (iii) dysplasia, indicated by coarse folds/grooves, meshlike villi, and foveolar appearance; and (iv) carcinoma, suggested by irregular-shaped mass lesions with ulcerations. The endoscopic criteria for intestinal metaplasia yielded a sensitivity of 100% in comparison with histology. Intestinal metaplasia with high-grade dysplasia was found in two rats and with low-grade dysplasia in three rats. Both focally invasive squamous cell carcinoma and invasive adenocarcinoma were found in one rat. Small animal endoscopy in a rat model of Barrett's esophagus can be used to perform surveillance, classify mucosal patterns, observe the onset of intestinal metaplasia, and monitor the progression of neoplastic transformation, representing a useful tool for studying the natural history of this disease.

Dendritic cells in Barrett's esophagus and esophageal adenocarcinoma

BACKGROUND

Like other premalignant conditions that develop in the presence of chronic inflammation, the development and progression of Barrett's esophagus is associated with the development of an immune response, but how this immune response is regulated is poorly understood. A comprehensive literature search failed to find any report of the presence of dendritic cells in Barrett's intestinal metaplasia and esophageal adenocarcinoma and this prompted our study.

MATERIAL AND METHODS

We used immunohistochemical staining and electron microscopy to examine whether dendritic cells are present in Barrett's esophagus and esophageal adenocarcinoma. Immunohistochemical staining with CD83, a specific marker for dendritic cells, was performed on paraffin-embedded sections of Barrett's intestinal metaplasia (IM, n = 12), dysplasia (n = 11) and adenocarcinoma (n = 14).

RESULTS

CD83+ cells were identified in the lamina propria surrounding intestinal type glands in Barrett's IM, dysplasia, and cancer tissues. Computerized quantitative analysis showed that the numbers of dendritic cells were significantly higher in cancer tissues. Double immunostaining with CD83, CD20, and CD3, and electron microscopy demonstrated that dendritic cells are present in Barrett's esophagus and form clusters with T cells and B cells directly within the lamina propria.

CONCLUSIONS

These findings demonstrate that dendritic cells are present in Barrett's tissues, with a significant increase in density in adenocarcinoma compared to benign Barrett's esophagus. Dendritic cells may have a role in the pathogenesis and immunotherapy treatment of Barrett's esophagus and adenocarcinoma.

Treatment modality and risk of development of dysplasia and adenocarcinoma in columnar-lined esophagus

Columnar metaplasia is the precursor lesion for esophageal adenocarcinoma, resulting from prolonged gastroesophageal reflux. The influence of the efficacy of reflux control on the development of neoplastic change in columnar-lined esophagus is not established. This study compares the rate of development of dysplasia and adenocarcinoma in patients with columnar metaplasia of the esophagus between patients treated pharmacologically and those treated with antireflux surgery. This study is a retrospective review of a cohort of patients enrolled in a multicenter national registry involving 738 patients from seven UK centers. Forty-one were treated with antireflux surgery, 42 with H2 receptor antagonist, 532 with proton pump inhibitor, and 114 with a combination of these medications. Nine had none of these medications or surgery. Total follow-up was 3697 years. Mean age and follow-up for patients treated medically were 61.6 and 4.96 years and surgically were 50.5 and 6.19 years, respectively. No patient in the surgical group developed high-grade dysplasia (HGD) or adenocarcinoma. Twenty patients treated medically developed adenocarcinoma and 10 developed HGD. Hazards ratio comparing pharmacological to surgical therapy for development of all grades of dysplasia and adenocarcinoma 1.77 (P = 0.272). Log rank test comparing antireflux surgery to pharmacological therapy for development of HGD or adenocarcinoma P = 0.1287 and for adenocarcinoma P = 0.2125. Although there was a trend towards greater efficacy of antireflux surgery over pharmacological therapy in reducing the development of dysplasia and adenocarcinoma, this did not reach statistical significance.

Reflux esophagitis, high-grade neoplasia, and early Barrett's carcinoma-what is the place of the Merendino procedure?

INTRODUCTION

Because of the increasing frequency of Barrett's cancer in Western industrialized countries, the management of reflux disease with the potential development of Barrett's esophagus, neoplasia, and early carcinoma is very important. In case of established Barrett's esophagus, the malignant degeneration of the specialized epithelium cannot definitely be prevented by antireflux surgery or continuous medication. Mucosal adenocarcinomas nearly never develop lymph node metastasis and can mostly be treated by endoscopic mucosectomy. The deeper the submucosa is infiltrated, the higher is the rate of lymph node metastasis which is, on the average, 30% for submucosal carcinoma.

CONCLUSIONS

Therefore, radical subtotal esophagectomy is the treatment of choice for submucosal carcinoma, whereas distal esophageal resection with limited lymph node dissection is only indicated in mucosal carcinoma which cannot be completely removed by interventional endoscopy.

Should patients with Barrett's oesophagus be kept under surveillance? The case for

Oesophageal adenocarcinoma is associated with high mortality rates and its incidence is increasing more rapidly than any other gastrointestinal cancer in the Western world. Several factors, including gastro-oesophageal reflux disease, smoking, alcohol and male gender, are associated with oesophageal adenocarcinoma but none can be used to identify accurately those individuals who will develop adenocarcinoma. It is generally accepted that oesophageal adenocarcinoma arises predominantly in Barrett's oesophagus and it is arguable that Barrett's oesophagus is currently the only clinically useful predictor of oesophageal adenocarcinoma. Surveillance - periodic testing to detect adenocarcinoma or its precursor, high grade dysplasia - is widely recommended for patients with Barrett's oesophagus with the aim of reducing mortality from oesophageal adenocarcinoma. The annual incidence of oesophageal adenocarcinoma in patients with Barrett's oesophagus is 0.5%-1.0% although there is marked variation between studies, attributable variously to publication bias, concurrent acid suppression therapy and differences in patient characteristics. There is limited evidence that surveillance reduces the incidence of oesophageal adenocarcinoma or consequent mortality and the cause of death for patients undergoing surveillance is often unrelated to oesophageal disease. There are, nonetheless, observational studies which suggest that surveillance is associated with earlier detection of malignancy and a reduction in mortality; in addition, data from modelling studies suggest that surveillance can be cost-effective. Furthermore, the advent of new, non-surgical treatments (endoscopic mucosal resection, photodynamic therapy, argon plasma coagulation) for high grade dysplasia and early cancer has reduced the risks associated with therapy for disease detected during surveillance. Surveillance programs have high drop out rates and, for patients who continue surveillance, adherence to standard, published protocols is highly variable. The establishment of specialist Barrett's oesophagus surveillance programs, with coordinator support, has considerable potential to improve adherence to current guidelines, pending the acquisition and publication of data from ongoing studies of chemoprophylaxis and surveillance in the management of Barrett's oesophagus. In consequence, although there is a paucity of data providing unequivocal demonstration of benefit, there is no proof that surveillance is ineffective. It is, therefore, appropriate to offer surveillance for Barrett's oesophagus in accordance with locally-applicable published guidelines after a full informed discussion of the risks and benefits of surveillance and therapy; continued participation should be reviewed regularly to accommodate changes in the patient's health and expectations.

When and how to grade Barrett's columnar metaplasia: the Prague system

Barrett's oesophagus (BO), a well-known precursor for oesophageal adenocarcinoma has been generating a great deal of controversy. The initial step in diagnosing BO requires an accurate endoscopic recognition of the columnar lined oesophagus. A reliable diagnosis of BO depends on its effective endoscopic recognition based on the key anatomic landmarks, followed by histological sampling of the columnar-lined epithelium. Precise localisation of the gastrooesophageal junction is pivotal in the endoscopic diagnosis of BO. Multiple ad-hoc grading systems and terminologies of BO have been proposed based on the Z-line appearance, presence or absence of intestinal metaplasia, and the length of Barrett's segment. However, a universally accepted standardised endoscopic grading system of BO is lacking. The Prague C&M criteria, developed by a subgroup of the International Working Group for the Classification of Oesophagitis, are the first explicit, consensus-driven, clinically relevant criteria for the endoscopic recognition and grading of BO that may be useful in both clinical practice and research trials.

The incidence of esophageal cancer and high-grade dysplasia in Barrett's esophagus: a systematic review and meta-analysis

Barrett's esophagus is a well-recognized precursor of esophageal adenocarcinoma. Surveillance of Barrett's esophagus patients is recommended to detect high-grade dysplasia (HGD) or early cancer. Because of wide variation in the published cancer incidence in Barrett's esophagus, the authors undertook a systematic review and meta-analysis of cancer and HGD incidence in Barrett's esophagus. Ovid Medline (Ovid Technologies, Inc., New York, New York) and EMBASE (Elsevier, Amsterdam, the Netherlands) databases were searched for papers published between 1950 and 2006 that reported the cancer/HGD risk in Barrett's esophagus. Where possible, early incident cancers/HGD were excluded, as were patients with HGD at baseline. Forty-seven studies were included in the main analysis, and the pooled estimate for cancer incidence in Barrett's esophagus was 6.1/1,000 person-years, 5.3/1,000 person-years when early incident cancers were excluded, and 4.1/1,000 person-years when both early incident cancer and HGD at baseline were excluded. Corresponding figures for combined HGD/cancer incidence were 10.0 person-years, 9.3 person-years, and 9.1/1,000 person-years. Compared with women, men progressed to cancer at twice the rate. Cancer or HGD/cancer incidences were lower when only high-quality studies were analyzed (3.9/1,000 person-years and 7.7/1,000 person-years, respectively). The pooled estimates of cancer and HGD incidence were low, suggesting that the cost-effectiveness of surveillance is questionable unless it can be targeted to those with the highest cancer risk.