Continuous treatment of Barrett's oesophagus patients with proton pump inhibitors up to 13 years: observations on regression and cancer incidence

Intestinal metaplasia in follow-up endoscopies among Asian patients with short-segment Barrett's esophagus: Regression, sampling error, and associated factors

BACKGROUND

The percentage of and factors associated with the regression of Barrett's esophagus (BE) or its characteristic intestinal metaplasia (IM) remain unclear, and conflicting results have been reported because of diverse regression and sampling error definitions. Thus, we investigated the rates of IM regression, sampling error, and associated factors.

METHODS

Forty-two patients with proven short-segment BE with IM who underwent two follow-up endoscopies with biopsies of Barrett's mucosa were retrospectively analyzed. Additional Alcian blue and MUC2 staining were done on the biopsy specimens without IM in hematoxylin-eosin staining. Only patients with negative hematoxylin-eosin, Alcian blue, and MUC2 staining for IM in both follow-up endoscopies were considered to have true regression. When all three stains were negative for IM in the first, but positive in the second follow-up endoscopy, we considered IM persisting and declared sampling error.

RESULTS

Among the 18 patients without IM at the first follow-up endoscopy, only five (11.9%) were judged to have true regression. Prolonged proton-pump inhibitor use was significantly associated with regression. Limited experience of the endoscopist, and insufficient biopsy number were significantly related to sampling error. Receiver operating characteristic (ROC) curve analysis showed the best cut-off value of the biopsy number/maximal-length (cm) ratio to predict sampling error was 2.25.

CONCLUSION

In our patients with short-segment BE, 11.9% experienced regression of IM. Prolonged proton-pump inhibitors treatment was associated with regression. An insufficient biopsy number was related to a missed IM, which may be eliminated by maintaining biopsy number/maximal-length (cm) ratio ≥2.25.

Assessment of the Relationship Between Gastric-Acid Suppressants and the Risk of Esophageal Adenocarcinoma: A Systematic Review and Meta-Analysis

Background

Esophageal cancer is a cancerous tumor that develops in the esophagus. It is the 10th most common cancer and has a low survival rate. Esophageal adenocarcinoma (EAC) is increasing in incidence globally. Those with EAC are affected by Barrett's esophagus metaplasia, which is attributed to genetic predisposition and is more common in men. Studies suggest that gastric acid suppressants, like proton pump inhibitors and histamine-2 receptor antagonists, have anticancer properties and reduce EAC. However, other research has suggested that they are not cancer-protective, and the use of antisecretory drugs is a risk factor for developing EAC.

Objective

This systematic review and meta-analysis investigated the properties and risk factors associated with using gastric acid suppressants in patients with EAC.

Methods

This meta-analysis used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Information from selected articles, including the lead author's name, year of publication, study setting, sample size, and gender, was extracted and recorded into an Excel (Microsoft, Redmond, Washington) form. Statistical data included odds ratio, hazard ratio, and/or risk ratio, with a 95% CI associated with patients with EAC and receiving gastric acid suppressants. Data were compared with individuals not receiving treatment. Publication bias was assessed using Begg's and Egger's tests. Statistical analyzes used Stata 14.0 (Stata LLC, College Station, Texas).

Results

The initial electronic literature search retrieved 3761 titles/abstracts. Extensive screening selected 20 articles for analysis. Odds ratios associated with EAC in the individuals using gastric acid suppressants were 0.77 (95% CI, 0.49-1.22; P = 0.274) and 0.67 (95% CI, 0.39-1.29; P = 0.240) for proton pump inhibitors and 1.02 (95% CI, 0.44-2.36; P = 0.967) for histamine-2 receptor antagonists.

Conclusions

The results found that gastric acid suppressants do not have a protective role in EAC and are not risk factors. Future studies of confounding variables and risk factors are needed to understand what affects EAC development.

Use of proton pump inhibitors for the risk of gastric cancer

BACKGROUND

This study aimed to systematically analyze the association between long-term use of proton pump inhibitors (PPIs) and the risk of gastric cancer (GC).

METHODS

We performed a systematic search of articles on the relationship between long-term use of PPIs and the risk of GC from PubMed and EMBASE. We calculated the pooled odds ratio of GC in PPI users compared to non-PPI users using random-effects models.

RESULTS

This meta-analysis included 18 studies from 20 different databases with 4348,905 patients enrolled. In the random effects model, we found that an increased risk of GC among PPI users (OR = 1.94; 95% CI [1.43, 2.64]). The long-term use of PPIs compared with histamine-2 receptor antagonist users did not increase the risk of GC (OR = 1.65; 95% CI [0.92, 2.97]). Stratified analysis showed that PPI users had a significantly increased risk of noncardia GC (OR = 2.53; 95% CI [2.03, 3.15]), but had a relatively small relationship with the risk of gastric cardia cancer. (OR = 1.79; 95% CI [1.06, 3.03]). With the extension of PPI use time, the estimated risk value decreases (<1 year: OR = 6.33, 95% CI [3.76, 10.65]; 1-3 years: OR = 1.82, 95% CI [1.30, 2.55]; >3 years: OR = 1.25, 95% CI [1.00, 1.56]). Despite Helicobacter pylori eradication, the long-term use of PPIs did not alter the increased risk of GC (OR = 2.29; 95% CI [1.57, 3.33]).

CONCLUSION

Our meta-analysis found that PPI use may be associated with an increased risk of GC. Further research on the causal relationship between these factors is necessary.

Chemoprevention in Barrett's esophagus and esophageal adenocarcinoma

There has been a dramatic increase in the incidence of Barrett's esophagus and esophageal adenocarcinoma over the past several decades with a continued rise expected in the future. Several strategies have been developed for screening and surveillance of patients with Barrett's esophagus and endoscopic treatment of Barrett's associated dysplasia and early esophageal cancer; however, they have not made a substantial impact on the incidence of cancer. Herein, chemoprevention becomes an attractive idea for reducing the incidence of cancer in Barrett's patients. Several agents appear promising in preclinical and observational studies but very few have been evaluated in randomized controlled trials. Strongest evidence to date is available for proton-pump inhibitors and Aspirin that have been evaluated in a large randomized controlled trial. Other agents such as statins, metformin, ursodeoxycholic acid, and dietary supplements have insufficient evidence for chemoprevention in Barrett's patients.

Antireflux and Endoscopic Therapies for Barrett Esophagus and Superficial Esophageal Neoplasia

Barrett esophagus (BE), defined as intestinal metaplasia of the distal esophageal mucosa, typically results from chronic gastroesophageal reflux disease and is the only known precursor of esophageal adenocarcinoma. The standard of care for the management of early esophageal neoplasia in the setting of BE has changed drastically over the past 15 years. Further investigation into diagnostic and therapeutic adjuncts will continue to improve our ability to control or cure BE before its advancement to a life-threatening malignancy.

Pathology, Chemoprevention, and Preclinical Models for Target Validation in Barrett Esophagus

Despite esophageal adenocarcinoma (EAC) being the most widespread among gastrointestinal cancers, with an 11-fold increase in the risk of cancer for patients with Barrett esophagus (BE), its prognosis is still poor. There is a critical need to better perceive the biology of cancer progression and identification of specific targets that are the hallmark of BE's progression. This review explores the established animal models of BE, including genetic, surgical and nonsurgical approaches, potential chemoprevention targets, and the reasoning behind their applications to prevent Barrett-related EAC. The key methodological features in the design feasibility of relevant studies are also discussed. Cancer Res; 78(14); 3747-54. ©2018 AACR.

Barrett Esophagus and Intramucosal Esophageal Adenocarcinoma

Barrett esophagus (BE) is a precursor lesion for esophageal adenocarcinoma (EAC). Developments in imaging and molecular markers, and endoscopic eradication therapy, are available to curb the increase of EAC. Endoscopic surveillance is recommended, despite lack of data. The cancer risk gets progressively downgraded, raising questions about the understanding of risk factors and molecular biology involved. Recent data point to at least 2 carcinogenic pathways operating in EAC. The use of p53 overexpression and high-risk human papillomavirus may represent the best chance to detect progressors. Genome-wide technology may provide molecular signatures to aid diagnosis and risk stratification in BE.

Safety of proton pump inhibitors and risk of gastric cancers: review of literature and pathophysiological mechanisms

INTRODUCTION

Despite being an overall safe drug, several long-term adverse effects are associated with proton pump inhibitors (PPIs). The link between PPI use and gastric neuroendocrine tumors (NETs), gastric adenocarcinomas and Barrett's esophagus progression gastric cancers has been investigated due to PPI-induced hypergastrinemia.

AREAS COVERED

The pathophysiological mechanisms underlying PPI exposure and gastric NETs, gastric adenocarcinomas and Barrett's esophagus progression are discussed. The quality of randomized control studies, cohort studies and case reports investigating the link between gastric cancers and PPIs are examined. Recommendations for clinicians are provided.

EXPERT OPINION

PPIs cause a hypergastrinemic state, increasing enterochromaffin-like cell dysplasia and risk of gastric NET development, increasing gastritis severity in the context of Helicobacter pylori infection, and progression of carcinogenesis in a certain predisposed subset of Barrett's esophagus patients. There are case reports of PPI-induced gastric NETs and adenocarcinomas as consequences of these effects. In pernicious anemia and chronic gastritis, clinicians should be aware of potential increased risk of gastric NET development with chronic PPI use in these patients. Eradication status of H. pylori prior to commencing long-term PPI therapy should be established to reduce the risk of severe atrophic gastritis and development of gastric dysplasia.

Microbiome and potential targets for chemoprevention of esophageal adenocarcinoma

Esophageal cancer is one of the deadliest cancers, with a dismal prognosis. It is increasingly recognized that esophageal cancer is a heterogeneous disease. It can be subdivided into two distinct groups: squamous cell carcinoma and adenocarcinoma, based on histological appearance. In the Western world, the incidence of squamous cell carcinoma was considerably higher than esophageal adenocarcinoma (EA) until the 1990s when, due to a dramatic increase, the incidence of EA surpassed that of squamous cell carcinoma. EA typically follows a well-established stepwise evolution from chronic inflammation due to reflux esophagitis (RE) that progresses to metaplasia (Barrett's esophagus [BE]) to dysplasia, which often culminates in EA. The pathophysiology of EA is complex and involves diverse factors, including gastroesophageal reflux, gastric acid secretion, dysfunction of the antireflux barrier, gastric emptying disturbances, and abnormalities in esophageal defense mechanisms. The current understanding of the etiology of EA is mainly derived from epidemiological studies of risk factors such as cigarette smoking, obesity, gastroesophageal reflux disorders (GERD), and low fruit and vegetable consumption. Numerous studies have been done, but the factors that drive the dynamic increase in the incidence of EA remain elusive. The advent of widespread antibiotic use occurred in the 1950s, preceding the surge of EA. Based on this temporal sequence, it has been hypothesized that antibiotics alter the microbiome to which the esophagus is exposed in patients who have GERD and that chronic exposure to this abnormal microbiome (ie, changes in species diversity or abundance) accounts for the increase in EA. If changes in the proposed factors alter the stepwise progression (RE-BE-dysplasia-EA), they may represent potential targets for chemoprevention. New discoveries will help improve our understanding of the biology and pathogenesis of these cancers, and aid in finding novel therapeutic targets.

Chemoprevention in Barrett's Esophagus: Current Status

Chemoprevention in Barrett's esophagus is currently applied only in research settings. Identifying pathways that can be targeted by safe, pharmaceutical or natural compounds is key to expanding the scope of chemoprevention. Defining meaningful surrogate markers of cancer progression is critical to test the efficacy of chemopreventive approaches. Combinatorial chemoprevention that targets multiple components of the same pathway or parallel pathways could reduce the risk and improve the efficacy of chemoprevention. Here we discuss the role of chemoprevention as an independent or an adjuvant management option in BE-associated esophageal adenocarcinoma.

The Effect of Proton Pump Inhibitors on Barrett's Esophagus

Proton pump inhibitors (PPIs) may protect against carcinogenesis in Barrett's esophagus because they eliminate the chronic esophageal inflammation of reflux esophagitis, and because they decrease esophageal exposure to acid, which can cause cancer-promoting DNA damage and increase proliferation in Barrett's metaplasia. Most clinical studies of PPIs and cancer development in Barrett's esophagus have found a cancer-protective effect for these drugs, although there are some contradictory data. Chemoprevention of dysplasia and cancer in Barrett's esophagus with PPIs appears to be cost-effective, and the indirect evidence supporting a cancer-protective role for PPIs is strong enough to warrant PPI treatment of virtually all patients with Barrett's esophagus.

Long-term proton pump inhibitor (PPI) use and the development of gastric pre-malignant lesions

BACKGROUND

Proton pump inhibitors (PPIs) are the most effective drugs to reduce gastric acid secretion. PPIs are one of the most commonly prescribed classes of medications worldwide. Apart from short-term application, maintenance therapy with PPIs is recommended and increasingly used in certain diseases, such as Zollinger-Ellison syndrome and gastro-oesophageal reflux disease, especially for people with erosive oesophagitis or Barrett's oesophagus. Although PPIs are generally safe, their efficacy and safety of long-term use remains unclear. The question of whether the long-term use of PPIs could promote the development of gastric pre-malignant lesions has been widely investigated, but results are inconsistent. Limited insight on this problem leads to a dilemma in decision making for long-term PPI prescription.

OBJECTIVES

To compare the development or progression of gastric pre-malignant lesions, such as atrophic gastritis, intestinal metaplasia, enterochromaffin-like (ECL) cell hyperplasia, and dysplasia, in people taking long-term (six months or greater) PPI maintenance therapy.

SEARCH METHODS

We searched the following databases (from inception to 6 August 2013): the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and CINAHL. In addition, we searched the reference lists of included trials and contacted experts in the field.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) in adults (aged 18 years or greater) concerning the effects of long-term (six months or greater) PPI use on gastric mucosa changes, confirmed by endoscopy or biopsy sampling (or both).

DATA COLLECTION AND ANALYSIS

Two review authors independently performed selection of eligible trials, assessment of trial quality, and data extraction. We calculated odds ratios (OR) for analysis of dichotomous data and mean differences for continuous data, with 95% confidence intervals (CI).

MAIN RESULTS

We included seven trials (1789 participants). Four studies had high risk of bias and the risk of bias in the other three trials was unclear. In addition, it was difficult to assess possible reporting bias. We pooled 1070 participants from four RCTs to evaluate corporal atrophy development revealing an insignificantly increased OR of 1.50 (95% CI 0.59 to 3.80; P value = 0.39; low-quality evidence) for long-term PPI users relative to non-PPI users. In five eligible trials, corporal intestinal metaplasia was assessed among 1408 participants, also with uncertain results (OR 1.46; 95% CI 0.43 to 5.03; P value = 0.55; low-quality evidence). However, by pooling data of 1705 participants from six RCTs, our meta-analysis showed that participants with PPI maintenance treatment were more likely to experience either diffuse (simple) (OR 5.01; 95% CI 1.54 to 16.26; P value = 0.007; very-low-quality evidence) or linear/micronodular (focal) ECL hyperplasia (OR 3.98; 95% CI 1.31 to 12.16; P value = 0.02; low-quality evidence) than controls. No participant showed any dysplastic or neoplastic change in any included studies.

AUTHORS' CONCLUSIONS

There is presently no clear evidence that the long-term use of PPIs can cause or accelerate the progression of corpus gastric atrophy or intestinal metaplasia, although results were imprecise. People with PPI maintenance treatment may have a higher possibility of experiencing either diffuse (simple) or linear/micronodular (focal) ECL cell hyperplasia. However, the clinical importance of this outcome is currently uncertain.

Acid-suppressive medications and risk of oesophageal adenocarcinoma in patients with Barrett's oesophagus: a systematic review and meta-analysis

BACKGROUND AND AIMS

Acid-suppressive medications, particularly proton pump inhibitors (PPIs), may decrease the risk of oesophageal adenocarcinoma (OAC) in patients with Barrett's oesophagus (BO). We performed a systematic review with meta-analysis of studies evaluating the association between acid-suppressive medications (PPIs and histamine receptor antagonists (H2RAs)) and risk of OAC or high-grade dysplasia (BO-HGD) in patients with BO.

METHODS

We performed a systematic search of multiple electronic databases and conference proceedings up to June 2013 to identify studies reporting the association between use of acid-suppressive medications and risk of OAC and/or BO-HGD in patients with BO. Summary ORs with 95% CIs were estimated.

RESULTS

We identified seven observational studies (2813 patients with BO, 317 cases of OAC or BO-HGD, 84.4% PPI users). On meta-analysis, PPI use was associated with a 71% reduction in risk of OAC and/or BO-HGD in patients with BO (adjusted OR 0.29; 95% CI 0.12 to 0.79). There was a trend towards a dose-response relationship with PPI use for >2-3 years protective against OAC or BO-HGD (three studies; PPI use >2-3 years vs <2-3 years: OR 0.45 (95% CI 0.19 to 1.06) vs 1.09 (0.47 to 2.56)). Considerable heterogeneity was observed. Two studies reported the association between H2RA use and risk of OAC and/or BO-HGD (1352 patients with BO, 156 cases of OAC, 25.4% on H2RAs), and both studies did not show a significant effect.

CONCLUSIONS

Based on meta-analysis of observational studies, the use of PPIs is associated with a decreased risk of OAC and/or BO-HGD in patients with BO. None of the studies showed an increased risk of OAC. PPI use should be considered in BO, and chemopreventive trials of PPIs in patients with BO are warranted.

Proton pump inhibitor use may not prevent high-grade dysplasia and oesophageal adenocarcinoma in Barrett's oesophagus: a nationwide study of 9883 patients

BACKGROUND

Proton pump inhibitors (PPI) may potentially modify and decrease the risk for development of oesophageal adenocarcinoma in Barrett's oesophagus (BO).

AIM

To investigate if the intensity and adherence of PPI use among all patients with BO in Denmark affected the risk of oesophageal adenocarcinoma.

METHODS

We performed a nationwide case-control study in Denmark among 9883 patients with a new diagnosis of BO. All incident oesophageal adenocarcinomas and high-grade dysplasias were identified, and risk ratios were estimated on the basis of prior use of PPIs. Sex- and age-matched BO patients without dysplasia or malignancies in a 10:1 ratio were used for comparison. Conditional logistic regression was used for analysis, adjusting for low-grade dysplasia, gender and medication.

RESULTS

We identified 140 cases with incident oesophageal adenocarcinomas and/or high-grade dysplasia, with a median follow-up time of 10.2 years. The relative risk of oesophageal adenocarcinoma or high-grade dysplasia was 2.2 (0.7-6.7) and 3.4 (95% CI: 1.1-10.5) in long-term low- and high-adherence PPI users respectively.

CONCLUSIONS

No cancer-protective effects from PPI's were seen. In fact, high-adherence and long-term use of PPI were associated with a significantly increased risk of adenocarcinoma or high-grade dysplasia. This could partly be due to confounding by indication or a true negative effect from PPIs. Until the results from future studies hopefully can elucidate the association further, continuous PPI therapy should be directed at symptom control and additional modalities considered as aid or replacement.

Barrett's Esophagus

OPINION STATEMENT

Barrett's esophagus (BE) is the most important and recognizable precursor lesion for esophageal adenocarcinoma (EAC), which is the one of the fastest-growing cancers in the Western world (600 % in the U.S. in the last 40 years), and therefore it is critical to manage the risk of cancer present in BE. New developments in imaging and molecular markers, as well as an armamentarium of novel and effective endoscopic eradication therapy - especially radio-frequency ablation (RFA) and endoscopic mucosal resection (EMR) - are now available to the interventional endoscopist to help curb the significant rise of esophageal adenocarcinoma (EAC). Endoscopic surveillance is currently recommended by most gastroenterology societies worldwide, although there is no data to support this practice in relation to reducing mortality from EAC. Paradoxically, the cancer risk in Barrett's esophagus is being progressively downgraded, which raises fundamental questions about our understanding of the risk factors and molecular biology of the Barrett's metaplasia-dysplasia-adenocarcinoma sequence. The recent discovery of a strong association of transcriptionally active high-risk human papillomavirus (hr-HPV) with Barrett's dysplasia (BD) and EAC may shed some light on this anomaly. It is imperative that we identify the high-risk group of progressors to EAC. While p53 immunohistochemistry is currently probably the best clinical molecular marker for predicting disease progression in BD, we must think outside the box and cast the net wide in search of additional biomarkers (e.g., high-risk human papilloma virus (hr-HPV)].

Two-year subjective, objective, quality of life, and endoscopic follow-up after laparoscopic Nissen-Rossetti in patients with columnar-lined esophagus

INTRODUCTION

Barrett esophagus (BE) is a complication of gastroesophageal reflux disease. We wish to determine the effects of surgery on the histology of the esophageal mucosa and evaluate Quality of Life.

MATERIALS AND METHODS

Twenty-seven patients with columnar-lined esophagus (CLE) metaplasia underwent laparoscopic Nissen-Rossetti fundoplication. Patients were submitted to close follow-up.

RESULTS

One patient voluntarily left follow-up after surgery. CLE was still present in 18 patients (66.6%); no patient developed dysplasia or esophageal adenocarcinoma. Two patients with gastric metaplasia and 1 patient with intestinal metaplasia had regression at 12 and 24 months after surgery (11.1%). DeMeester and Johnson score decreased from 38.69 (SD ± 51.44) to 11.99 (SD ± 18.08) at 6 months, 12.69 (SD ± 12.91) at 12 months, and it was 11.38 (SD ± 6.43) at 24 months. Preoperative gastroesophageal reflux disease-health related quality of life was 19.90 (SD ± 18.54), 9.80 (SD ± 8.77) at 6 months, 9.57 (SD ± 9.14) at 12 months, and 11.53 (SD ± 6.48) at 24 months. Short form-36 measurement showed significant improvement.

CONCLUSIONS

Management of CLE requires multidisciplinary approach. Medical therapy does not prevent biliary reflux into the esophagus. Surgical therapy is effective and long lasting. It should be performed by experienced surgical teams.

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.

Statin use is associated with a reduction in the incidence of esophageal adenocarcinoma: a case control study

The incidence of esophageal adenocarcinoma (EAC) is increasing significantly throughout the developed world. As yet, there are no proven chemopreventive strategies. In laboratory studies, aspirin, non-steroidal anti-inflammatory drugs and statins have promising chemopreventive actions. Several observational studies support a protective effect of aspirin and non-steroidal anti-inflammatory drugs, but there are only limited clinical data exploring the potential protective effect of statins. We conducted a case-control study examining aspirin and statin use in patients with EAC. Cancer cases were compared against age-sex-matched controls attending for diagnostic upper gastrointestinal endoscopy. Risk factor and drug exposure were established using standardized interviews. Logistic regression was used to compare statin exposure and correct for confounding factors. A total of 112 cases and 448 controls were enrolled. Statin use was associated with a significantly lower incidence of EAC (odds ratio 0.52, 95% confidence interval 0.27-0.92). Aspirin use was also associated with apparent protection against EAC (odds ratio 0.68, 95% confidence interval 0.28-0.92), and a significantly greater effect was seen with the combination of statin plus aspirin (odds ratio 0.27, 95% confidence interval 0.05-0.67). There was a significant trend for greater risk reduction with longer duration and higher doses of statin use. Simvastatin comprised the majority of statin use, but similar effects were seen with simvastatin and non-simvastatin agents. In this observational study, patients regularly using statins or aspirin had a lower incidence of EAC. Statins may have clinically useful effects in preventing the development of EAC.

The esophagitis to adenocarcinoma sequence; the role of inflammation

Esophageal adenocarcinoma (EAC) is the eighth most common cancer worldwide, and approximately 15% of patients survive 5years. Reflux disease (GERD) and Barrett's esophagus (BE) are major risk factors for the development of EAC, and epidemiologic studies highlight a strong association with obesity. The immune, inflammatory and intracellular signaling changes resulting from chronic inflammation of the esophageal squamous epithelium are increasingly well characterized. In GERD and Barrett's, an essential role for T-cells in the initiation of inflammation in the esophagus has been identified, and a balance between T-cell responses and phenotype may play an important role in disease progression. Obesity is a chronic low-grade inflammatory state, fueled by adipose tissue derived- inflammatory mediators such as IL-6, TNF-α and leptin, representing a novel area for targeted research. Additionally, reactive oxygen species (ROS) and receptor tyrosine kinase (RTK) activation may drive progression from esophagitis to EAC, and downstream signaling pathways employed by these molecules may be important. This review will explain the diverse range of mechanisms potentially driving and maintaining inflammation within the esophagus and explore both existing and future therapeutic strategies targeting the process.

Managing Barrett's esophagus with radiofrequency ablation

Barrett's esophagus (BE) is a well-established pre-malignant lesion for esophageal adenocarcinoma, a condition that carries a dismal five-year overall survival rate of less than 15%. Among several available methods to eliminate BE, radiofrequency ablation (RFA) provides the most efficient modality, since it has been demonstrated to successfully eradicate BE with or without dysplasia with acceptable safety, efficacy and durability profiles. In conjunction with proton pump therapy, this new technology has quickly become the standard care for patients with dysplastic BE. However, several technical questions remain about how to deploy RFA therapy for maximum effectiveness and long-term favorable outcomes for all stages of the disease. These include how to select patient for therapy, what the best protocol for RFA is, when to use other modalities, such as endoscopic mucosal resection, and what should be considered for refractory BE. This review addresses these questions with the perspective of the best available evidence matched with the authors' experience with the technology.

Article Commentary: Management of Barrett's Esophagus

Barrett's esophagus is a pathologic change of the normal squamous epithelium of the esophagus to specialized columnar metaplasia. Barrett's esophagus is a result of prolonged exposure of the esophagus to gastroduodenal refluxate. Although Barrett's itself is not symptomatic, and, in fact, patients with Barrett's esophagus may be completely asymptomatic, it does identify patients at higher risk of developing esophageal adenocarcinoma. Traditionally, antireflux surgery was reserved for patients with symptoms, because it was believed that antireflux surgery did not eliminate Barrett's esophagus and reduce cancer risk. Rationale for the treatment of Barrett's esophagus beyond treating symptoms of gastroesophageal reflux disease stems from the hope to decrease, if not eliminate, the risk of adenocarcinoma. Treatment options ranged from medical acid suppression without surveillance to resection. Ablation, particularly endoscopic radio-frequency ablation, has become the standard of care for Barrett's esophagus with high-grade dysplasia. It role in nondysplastic or low-grade dysplastic Barrett's is less clear. Combined endoscopic mucosal resection with ablation is effective in nodular high-grade Barrett's esophagus. Resection should be reserved for patients with persistent high-grade dysplasia despite multiple attempts at endoscopic ablation or resection or for patients with evidence of carcinoma.

Barrett esophagus: what a mouse model can teach us about human disease

The incidence of esophageal adenocarcinoma (EAC) is rapidly rising in the western world and accounts for 2% of all cancer-related deaths. The precursor lesion for EAC is Barrett esophagus (BE), which is strongly associated with gastresophageal reflux disease. A major limitation to the study of EAC has been the absence of tractable and genetically modifiable preclinical models of BE. A mouse model of BE and EAC that resembles human disease could provide novel insights into the origins and molecular pathogenesis of BE. In addition, validated animal models could help stratify BE patients given the limited predictive power of current standard endoscopic measures and clinical assessment. Here, we review the findings from recently developed mouse models of BE and EAC and their impact on clinical decision making, surveillance programs and therapeutic options. The data, taken together, suggest potential origins of BE from the gastric cardia, a role of bile acid and hypergatrinemia for carcinogenesis, a growing importance for columnar-like epithelium and a critical role for Notch signaling.

Effective intra-esophageal acid control is associated with improved radiofrequency ablation outcomes in Barrett's esophagus

BACKGROUND

Endoscopic radiofrequency ablation (RFA) is a promising new treatment of Barrett's esophagus (BE). Adjunctive intra-esophageal pH control with proton pump inhibitors and/or anti-reflux surgery is generally recommended to optimize squamous re-epithelialization after ablation.

AIMS

The aims of this study were to examine the association between intra-esophageal pH control and RFA outcomes and to identify predictive factors to achieve complete elimination (CE) of BE following RFA.

METHODS

We retrospectively studied the outcomes of BE patients treated with RFA. Esophageal acid exposure (EAE) was assessed utilizing 24-h pH monitoring on therapy. CE was endoscopically defined as no area suspicious for residual metaplasia following RFA.

RESULTS

Of 45 patients (33 men; mean age 61.6, mean BE length C4.1 M4.6) examined for EAE, 29 % exhibited moderate-severe EAE despite therapy. Reduction in BE surface area and CE rate were higher in the normal-mild EAE group compared with the moderate-severe EAE group (99 vs. 95 %, p = 0.02; 44 vs. 15 %, p = 0.09, respectively). Using univariate analysis, age, gender, race, aspirin/NSAIDs use, baseline worst histology, baseline BE surface area, and the number or types of RFA had no correlation with CE. By multivariate multiple logistic regression analysis, normal-mild EAE and smaller hiatal hernia were independent factors associated with CE.

CONCLUSIONS

Effective intra-esophageal pH control is associated with improved RFA outcomes of BE. Normal to mild EAE and smaller hiatal hernia are predictive factors to achieve CE. Given the frequent persistence of acid reflux despite therapy in BE patients, in order to maximize the RFA effects esophageal pH optimization and hernia repair should be considered.

Management of Barrett's oesophagus and intramucosal oesophageal cancer: a review of recent development

Barrett's oesophagus is the most important and recognizable precursor lesion for oesophageal adenocarcinoma, which is the one of the fastest growing cancers in the Western World. The incidence of oesophageal adenocarcinoma has increased 600% in the United States between 1975 and 2001 and is thought to represent a real increase in burden rather than a result of histologic or anatomical misclassification or overdiagnosis. Thus, the cancer risk in Barrett's oesophagus has to be managed and involves prevention (surveillance endoscopy), treating underlying gastroesophageal reflux disease (medically and or surgically) and endoscopic therapy to remove diseased epithelium in appropriate patient subgroups. In the last decade, new developments in imaging and molecular markers as well as an armamentarium of novel and effective endoscopic eradication therapy has become available to the endoscopist to combat this exponential rise in oesophageal adenocarcinoma. Paradoxically, the cancer risk in Barrett's oesophagus gets progressively downgraded which raises fundamental questions about our understanding of the known and unknown risk factors and molecular aberrations that are involved in the Barrett's metaplasia-dysplasia-carcinoma sequence. Future research has to be directed at these areas to fine tune our screening and surveillance programs to identify more accurately the high-risk group of progressors to oesophageal adenocarcinoma who would benefit most from endoscopic therapy.

Diagnosis and management of Barrett's esophagus

Barrett esophagus is characterized by the replacement of squamous mucosa in the esophagus by specialized intestinal metaplasia. Its clinical significance lies in it being the strongest risk factor for and known precursor for esophageal adenocarcinoma. Diagnosis requires endoscopic confirmation of columnar metaplasia in the distal esophagus and histologic confirmation of specialized intestinal metaplasia. Recommendations for the management of subjects diagnosed with Barrett esophagus include periodic endoscopic surveillance to detect the development of high-grade dysplasia or adenocarcinoma. Careful endoscopic evaluation with high-resolution endoscopy and endoscopic resection is recommended in the evaluation of subjects with high-grade dysplasia and early adenocarcinoma.

Diagnosis and management of Barrett's esophagus

Barrett esophagus is characterized by the replacement of squamous mucosa in the esophagus by specialized intestinal metaplasia. Its clinical significance lies in it being the strongest risk factor for and known precursor for esophageal adenocarcinoma. Diagnosis requires endoscopic confirmation of columnar metaplasia in the distal esophagus and histologic confirmation of specialized intestinal metaplasia. Recommendations for the management of subjects diagnosed with Barrett esophagus include periodic endoscopic surveillance to detect the development of high-grade dysplasia or adenocarcinoma. Careful endoscopic evaluation with high-resolution endoscopy and endoscopic resection is recommended in the evaluation of subjects with high-grade dysplasia and early adenocarcinoma.

Regular statin and aspirin use in patients with Barrett's oesophagus is associated with a reduced incidence of oesophageal adenocarcinoma

BACKGROUND

Oesophageal adenocarcinoma (OAC) has a poor prognosis, and chemoprevention is an attractive option to reduce the burden of the disease. Hydroxyl-methyl-CoA reductase inhibitors (statins) have been shown to exert potentially useful anticancer effects against OAC cell lines, but there are only limited clinical data examining the effects of statins on the incidence of OAC.

AIM

To examine the association between statin use and the incidence of OAC.

METHODS

We have carried out a case-control study comparing statin use between patients with an incident diagnosis of OAC and controls with nonprogressive Barrett's oesophagus. Eighty-five cancer cases were compared with 170 age-matched and sex-matched controls. Risk factors and drug exposure were established using standardized interviews. Logistic regression was used to compare statin exposure and correct for confounding factors.

RESULTS

Regular statin use was associated with a significantly lower incidence of OAC [uncorrected odds ratio (OR) 0.45, 95% confidence intervals 0.24-0.84)]. After correction for confounding variables including aspirin and NSAID use, statin use was still associated with a reduced incidence of OAC (OR 0.57, 0.28-0.94). Longer duration of statin use and higher doses were both associated with a significantly greater reduction in OAC. The combination of regular statin and aspirin use was associated with a significantly further reduced incidence of OAC (OR 0.31, 0.04-0.69).

CONCLUSION

In this observational case-control study, the regular use of statins was associated with a reduced incidence of OAC. The chemopreventative actions of statins, especially in conjunction with aspirin, deserve further study.

Barrett's Esophagus: Emerging Knowledge and Management Strategies

The incidence of esophageal adenocarcinoma (EAC) has increased exponentially in the last 3 decades. Barrett's esophagus (BE) is the only known precursor of EAC. Patients with BE have a greater than 40 folds higher risk of EAC compared with the general population. Recent years have witnessed a revolution in the clinical and molecular research related to BE. However, several aspects of this condition remain controversial. Data regarding the true prevalence of BE have varied widely. Recent studies have suggested a lower incidence of EAC in nondysplastic BE (NDBE) than previously reported. There is paucity of prospective data showing a survival benefit of screening or surveillance for BE. Furthermore, the ever-increasing emphasis on healthcare cost containment has called for reexamination of the screening and surveillance strategies for BE. There is a need for identification of reliable clinical predictors or molecular biomarkers to risk-stratify patients who might benefit the most from screening or surveillance for BE. Finally, new therapies have emerged for the management of dysplastic BE. In this paper, we highlight the key areas of controversy and uncertainty surrounding BE. The paper discusses, in detail, the current literature about the molecular pathogenesis, biomarkers, histopathological diagnosis, and management strategies for BE.

Risk factors and chemoprevention in Barrett's esophagus--an update

OBJECTIVE

Barrett's esophagus (BO) is a precursor of esophageal adenocarcinoma (OAC), a cancer with a poor prognosis and an increasing incidence. Hence there is an interest in mapping causal factors underlying BO and finding strategies to reduce the risk of dysplasia progression in patients with BO. Here we review current knowledge on established as well as less risk factors for the development of BO. Additionally, we summarize today's status on the use of chemoprevention aiming to reduce the risk of cancer progression in BO patients.

METHODS

We searched Medline and the Cochrane Library using the MeSH terms "Barrett's esophagus" and "Barrett esophagus," both alone and combined with the terms "risk factor," "aetiology," "diet," or "prevention." Focus was on original contributions, systematic reviews, and meta-analyses.

RESULTS

Established risk factors for the development of BO include gastro-esophageal reflux, obesity, male gender, Caucasian ethnicity, and increasing age. Smoking might increase the risk of BO, while aspirin/NSAIDs, Helicobacter pylori infection, and specific "healthy" dietary factors may lower the risk. The potential value of using chemoprevention with proton pump inhibitors, aspirin/NSAIDs, or statins is still uncertain.

CONCLUSIONS

There is today a substantial knowledge of risk factors of BO. Certain diet may be protective of BO, albeit yet to be proven. The efficiency of chemoprevention in BO is currently addressed further in randomized clinical trials.

Subsquamous intestinal metaplasia: implications for endoscopic management of Barrett's esophagus

Buried Barrett's, or subsquamous intestinal metaplasia (SSIM), is defined as the presence of metaplastic, columnar tissue beneath overlying squamous epithelium. Therefore, SSIM cannot be detected by endoscopic visual examination alone; it is detectable only by tissue biopsy. SSIM can develop in patients with Barrett's esophagus (BE) after chronic pharmacologic suppression of gastric acid; it has been identified before and after endoscopic ablative therapies in cohort studies. It is important to determine the malignant potential of SSIM and the effects of endoscopic therapy for BE on development of SSIM; answers to these questions could affect long-term endoscopic surveillance and ablation strategies for patients with BE.

Current status and future perspectives on the etiology of esophageal adenocarcinoma

Esophageal adenocarcinoma is the most common type of esophageal cancer in most Western countries and is an important contributor to overall cancer mortality. Most cases of esophageal adenocarcinoma are believed to arise from Barrett’s esophagus. Esophageal adenocarcinoma occurs more frequently in white men over 50 years old, as well as in people with frequent symptoms of gastroesophageal reflux, in smokers and in people who are obese. Higher consumption of fruit and vegetables, use of non-steroidal anti-inflammatory drugs, and infection with Helicobacter pylori have all been shown to reduce the risk of esophageal adenocarcinoma. Here, we review the epidemiological evidence for the major risk factors of esophageal adenocarcinoma and also discuss perspectives for future research.

Barrett's esophagus and β-carotene therapy: symptomatic improvement in GERD and enhanced HSP70 expression in esophageal mucosa

INTRODUCTION

Epidemiological studies suggest a protective role for β-carotene with several malignancies. Esophageal adenocarcinoma frequently arises from Barrett's esophagus (BE). We postulated that β-carotene therapy maybe protective in BE.

MATERIALS AND METHOD

We conducted a prospective study in which 25 mg of β-carotene was administered daily for six-months to six patients. Each patient underwent upper endoscopy before and after therapy and multiple mucosal biopsies were obtained. Additionally, patients completed a gastroesophageal reflux disease (GERD) symptoms questionnaire before and after therapy and severity score was calculated. To study the effect of β-carotene at molecular level, tissue extracts of the esophageal mucosal biopsy were subjected to assessment of heat-shock protein 70 (HSP70).

RESULTS

A significant (p<0.05) reduction in mean GERD symptoms severity score from 7.0±2.4 to 2.7±1.7 following β-carotene therapy was noted. Measurement of Barrett's segment also revealed a significant reduction in mean length after therapy. In fact, two patients had complete disappearance of intestinal metaplasia. Furthermore, marked enhancement of HSP70 expression was demonstrated in biopsy specimens from Barrett's epithelium in four cases that were tested.

CONCLUSIONS

Long- term β-carotene therapy realizes amelioration of GERD symptoms along with restitution of the histological and molecular changes in esophageal mucosa of patients with BE, associated with concurrent increase in mucosal HSP70 expression.

Optimal management of Barrett's esophagus: pharmacologic, endoscopic, and surgical interventions

Esophageal adenocarcinoma and its precursor, Barrett’s esophagus, are rapidly rising in incidence. This review serves to highlight the role of pharmacologic, endoscopic, and surgical intervention in the management of Barrett’s esophagus, which requires acid suppression and endoscopic assessment. Treatment with a proton pump inhibitor may decrease acid exposure and delay the progression to dysplasia. Patients who require aspirin for cardioprotection or other indications may also benefit in terms of a protective effect against the development of esophageal cancer. However, without other indications, aspirin is not indicated solely to prevent cancer. A careful endoscopic examination should include assessment of any visible lesions in a Barrett’s segment. An expert gastrointestinal pathologist should confirm neoplasia in the setting of Barrett’s esophagus. For those patients with high-grade dysplasia or intramucosal carcinoma, careful consideration of endoscopic therapy or surgical therapy must be given. All visible lesions in the setting of dysplasia should be targeted with focal endoscopic mucosal resection for both accurate histopathologic diagnosis and treatment. The remainder of the Barrett’s epithelium should be eradicated to address all synchronous and metachronous lesions. This may be done by tissue acquiring or nontissue acquiring means. Radiofrequency ablation has a positive benefit-risk profile for flat Barrett’s esophagus. At this time, endoscopic therapy is not indicated for nondysplastic Barrett’s esophagus. Esophagectomy is still reserved for selected cases with evidence of lymph node metastasis, unsuccessful endoscopic therapy, or with high-risk features of high-grade dysplasia or intramucosal carcinoma.

Role of acid suppression in the development and progression of dysplasia in patients with Barrett's esophagus

Barrett's esophagus (BE) usually develops in patients with gastroesophageal reflux disease and therefore it has been suggested that esophageal acid exposure plays an import role in the initiation of BE and its progression towards esophageal adenocarcinoma (EAC). The mechanisms whereby acid exposure causes BE are not completely revealed and the potential role of esophageal acid exposure in carcinogenesis is unclear as well. Since acid exposure is thought to play an important role in the progression of BE, therapies aimed at preventing the development of EAC have primarily focused on pharmacological and surgical acid suppression. In clinical practice, acid suppression is effective in relieving reflux symptoms and decreases esophageal acid exposure in most patients. However, in some individuals, pathological acid exposure persists and these patients continue to be at risk for developing dysplasia or EAC. To date, published trials suggest that acid suppression is able to prevent the development and progression of dysplasia in patients with BE, but definite and compelling proof is still lacking. This article reviews the mechanisms of acid-induced carcinogenesis in BE and the role of acid suppression in the prevention of neoplastic progression.

Barrett's esophagus: endoscopic treatments II

The following on endoscopic treatments of Barrett's esophagus includes commentaries on animal experiments on cryotherapy; indications for cryotherapy, choice of dosimetry, number of sessions, and role in Barrett's esophagus and adenocarcinoma; recent technical developments of RFA technology and long-term effects; the comparative effects of diverse ablation procedures and the rate of recurrence following treatment; and the indications for treatment of dysplasia and the role of radiofrequency ablation.

Chemoprevention in Barrett's oesophagus

Barrett's oesophagus normally affects the distal oesophagus when metaplastic columnar lined epithelium replaces stratified squamous epithelium which predisposes to cancer development. This develops as a consequence of chronic gastroesophageal reflux (GORD). Those with Barrett's have a 40 fold increased risk of oesophageal adenocarcinoma [1]. There are is still a lack of understanding of the natural history of the cell of origin. This does hamper research into this area. We accept that there is a limitation in testing of the pathogenesis of Barrett's oesophagus due to a lack of a universally accepted animal model. The major questions surrounding Barrett's oesophagus include validity of surveillance strategies, the optimal treatment and more importantly an agent that can prevent progression to cancer without unacceptable side effects. The main chemopreventative agents that show promise are aspirin and proton pump inhibitors (PPIs). There are other agents such as green tea, berries and antioxidants and diet that have been suggested; we discuss the evidence available for these strategies. We hope for continued improvement in the clinical trial infrastructure to facilitate testing of new pharmacological and endoscopic interventions for Barrett's oesophagus.