A combination of esomeprazole and aspirin reduces tissue concentrations of prostaglandin E(2) in patients with Barrett's esophagus

Drug repurposing for cancer therapy

Cancer, a complex and multifactorial disease, presents a significant challenge to global health. Despite significant advances in surgical, radiotherapeutic and immunological approaches, which have improved cancer treatment outcomes, drug therapy continues to serve as a key therapeutic strategy. However, the clinical efficacy of drug therapy is often constrained by drug resistance and severe toxic side effects, and thus there remains a critical need to develop novel cancer therapeutics. One promising strategy that has received widespread attention in recent years is drug repurposing: the identification of new applications for existing, clinically approved drugs. Drug repurposing possesses several inherent advantages in the context of cancer treatment since repurposed drugs are typically cost-effective, proven to be safe, and can significantly expedite the drug development process due to their already established safety profiles. In light of this, the present review offers a comprehensive overview of the various methods employed in drug repurposing, specifically focusing on the repurposing of drugs to treat cancer. We describe the antitumor properties of candidate drugs, and discuss in detail how they target both the hallmarks of cancer in tumor cells and the surrounding tumor microenvironment. In addition, we examine the innovative strategy of integrating drug repurposing with nanotechnology to enhance topical drug delivery. We also emphasize the critical role that repurposed drugs can play when used as part of a combination therapy regimen. To conclude, we outline the challenges associated with repurposing drugs and consider the future prospects of these repurposed drugs transitioning into clinical application.

Revisiting Proton Pump Inhibitors as Chemoprophylaxis Against the Progression of Barrett's Esophagus

PURPOSE OF REVIEW

Barrett's esophagus (BE) is associated with chronic gastroesophageal reflux disease and is a known precursor to esophageal adenocarcinoma. While endoscopic surveillance strategies and the role for endoscopic eradication therapy have been well established, there has been much interest in identifying chemopreventive agents to disrupt or halt the metaplasia-dysplasia-carcinoma sequence in patients with BE.

RECENT FINDINGS

No pharmacological agent has held more hope in reducing the risk of neoplastic progression in BE than proton pump inhibitors (PPIs). However, data supporting PPIs for chemoprevention have largely been from observational cohort and case-control studies with mixed results. In this review, we revisit the literature and highlight the role of PPIs in patients with BE as it pertains to chemoprophylaxis against the progression of BE to dysplasia and esophageal adenocarcinoma.

Translating Molecular Biology Discoveries to Develop Targeted Cancer Interception in Barrett's Esophagus

Esophageal adenocarcinoma (EAC) is a rapidly increasing lethal tumor. It commonly arises from a metaplastic segment known as Barrett's esophagus (BE), which delineates the at-risk population. Ample research has elucidated the pathogenesis of BE and its progression from metaplasia to invasive carcinoma; and multiple molecular pathways have been implicated in this process, presenting several points of cancer interception. Here, we explore the mechanisms of action of various agents, including proton pump inhibitors, non-steroidal anti-inflammatory drugs, metformin, and statins, and explain their roles in cancer interception. Data from the recent AspECT trial are discussed to determine how viable a multipronged approach to cancer chemoprevention would be. Further, novel concepts, such as the repurposing of chemotherapeutic drugs like dasatinib and the prevention of post-ablation BE recurrence using itraconazole, are discussed.

Variation in Fatty Acid Synthase, Ki67 and p53 Esophageal Mucosa Expressions in Barrett's Esophagus Patients Treated for One Year with Two Esomeprazole Different Regimens

Barrett's esophagus (BE) is an acquired pre-malignant condition that results from chronic gastroesophageal reflux. The malignant transformation occurred in 0.5% of patients/year and was independent of medical and endoscopic conservative treatments. Fatty acid synthase (FAS) is a multifunctional enzyme that catalyzes the synthesis of long-chain fatty acids from acetyl-coenzyme A, malonyl-coenzyme A, a reduced form of nicotinamide adenine dinucleotide phosphate (NADPH), and adenosine triphosphate. Activation of FAS is closely linked to malignant transformation. The aim of the present study was to evaluate the variation of FAS, p53, and Ki67 expressions in two groups of 21 BE patients each, after one year of continuous (group A) or discontinuous (group B) treatment with esomeprazole 40 mg/day in comparison to the initial expression. In both the two groups of BE patients, biopsies were taken from pathologic sites of the mucosa for histological and immuno-histochemical detection of FAS, Ki67, and p53 at entry and after one year of Esomeprazole 40 mg treatment. FAS expression was positive when a strong granular cytoplasmic staining was observed in esophageal cells. Ki67 and p53 were defined as positive when nuclear staining was clearly detected at ×10 magnification. FAS expression was reduced in 43% of patients treated with Esomeprazole continuously in comparison to the 10% of patients treated with Esomeprazole on demand (p = 0.002). Ki67 expression was reduced in 28% of continuously treated patients in comparison to 5% of patients treated on demand (p = 0.001). The p53 expression decreased in 19% of continuously treated patients in comparison to an increase in 2 patients (9%) treated on demand (p = 0.05). Continuously Esomeprazole treatment could help in the diminution of metabolic and proliferative activities in the esophageal columnar epithelium and in part it can help prevent the oxidative damage against cellular DNA, resulting in a diminution in p53 expression.

Pharmacological Inhibition of Exosome Machinery: An Emerging Prospect in Cancer Therapeutics

Abstract:

Exosomes are nanocarriers that mediate intercellular communication, crucial for normal physiological functions. However, exponentially emerging reports have correlated their dysregulated release with various pathologies, including cancer. In cancer, from stromal remodeling to metastasis, where tumor cells bypass the immune surveillance and show drug resistivity, it has been established to be mediated via tumor-derived exosomes. Owing to their role in cancer pathogenicity, exosome-based strategies offer enormous potential in treatment regimens. These strategies include the use of exosomes as a drug carrier or as an immunotherapeutic agent, which requires advanced nanotechnologies for exosome isolation and characterization. In contrast, pharmacological inhibition of exosome machinery surpasses the requisites of nanotechnology and thus emerges as an essential prospect in cancer therapeutics. In this line, researchers are currently trying to dissect the molecular pathways to reveal the involvement of key regulatory proteins that facilitate the release of tumor-derived exosomes. Subsequently, screening of various molecules in targeting these proteins, with eventual abatement of exosome-induced cancer pathogenicity, is being done. However, their clinical translation requires more extensive studies. Here we comprehensively review the molecular mechanisms regulating exosome release in cancer. Moreover, we give insight into the key findings that highlight the effect of various drugs as exosome blockers, which will add to the route of drug development in cancer management.

Diagnosis and Management of Barrett's Esophagus: An Updated ACG Guideline

Barrett's esophagus (BE) is a common condition associated with chronic gastroesophageal reflux disease. BE is the only known precursor to esophageal adenocarcinoma, a highly lethal cancer with an increasing incidence over the last 5 decades. These revised guidelines implement Grading of Recommendations, Assessment, Development, and Evaluation methodology to propose recommendations for the definition and diagnosis of BE, screening for BE and esophageal adenocarcinoma, surveillance of patients with known BE, and the medical and endoscopic treatment of BE and its associated early neoplasia. Important changes since the previous iteration of this guideline include a broadening of acceptable screening modalities for BE to include nonendoscopic methods, liberalized intervals for surveillance of short-segment BE, and volume criteria for endoscopic therapy centers for BE. We recommend endoscopic eradication therapy for patients with BE and high-grade dysplasia and those with BE and low-grade dysplasia. We propose structured surveillance intervals for patients with dysplastic BE after successful ablation based on the baseline degree of dysplasia. We could not make recommendations regarding chemoprevention or use of biomarkers in routine practice due to insufficient data.

Aspirin use for cancer prevention: A systematic review of public, patient and healthcare provider attitudes and adherence behaviours

We undertook a systematic review to synthesise the data on attitudes and behaviour towards the use of aspirin for cancer prevention, and healthcare providers' attitudes towards implementing aspirin in practice. Searches were carried out across 12 databases (e.g. MEDLINE, EMBASE). We used the Mixed Methods Appraisal Tool to evaluate study quality, and conducted a narrative synthesis of the data. The review was pre-registered (PROSPERO: CRD42018093453). Thirty-eight studies were identified. Uptake and adherence data were all from trials. Trials recruited healthy participants, those at higher risk of cancer, and those with cancer. Four studies reported moderate to high (40.9-77.7%) uptake to an aspirin trial among people who were eligible. Most trials (18/22) reported high day-to-day adherence (≥80%). Three trials observed no association between gender and adherence. One trial found no association between adherence and colorectal cancer risk. Three studies reported moderate to high (43.6-76.0%) hypothetical willingness to use aspirin. Two studies found that a high proportion of healthcare providers (72.0-76.0%) perceived aspirin to be a suitable cancer prevention option. No qualitative studies were identified. The likelihood that eligible users of aspirin would participate in a trial evaluating the use of aspirin for preventive therapy was moderate to high. Among participants in a trial, day-to-day adherence was high. Further research is needed to identify uptake and adherence rates in routine care, the factors affecting aspirin use, and the barriers to implementing aspirin into clinical care.

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.

Proton pump inhibitor omeprazole suppresses carcinogen induced colonic adenoma progression to adenocarcinoma in F344 rat

Colorectal cancer (CRC) causes over 53,000 deaths annually in the United States. Its rising incidences worldwide and particularly in young adults is a major concern. Here, we evaluated the efficacy of omeprazole (OME) that is clinically approved for treating acid-reflux, to enable its repurposing for CRC prevention. In the azoxymethane (AOM)-induced rat CRC model, dietary OME (250 and 500 ppm) was administered at early adenoma stage (8 weeks after AOM) to assess the progression of early lesions to adenocarcinoma. Administration of OME at 250 ppm or 500 ppm doses led to suppression of total colon adenocarcinoma incidence by 15.7% and 32% (p<0.01), respectively. Importantly, invasive carcinoma incidence was reduced by 59% (p<0.0005) and 90% (p<0.0001) in OME administered rats in a dose-dependent manner. There was also a strong and dose-dependent inhibition in the adenocarcinoma multiplicity in rats exposed to OME. Administration of 250 and 500 ppm OME inhibited total colon adenocarcinoma multiplicity by ~49% and ~65% (p<0.0001), respectively. While non-invasive adenocarcinomas multiplicity was suppressed by ~34% to ~48% (p<0.02), the invasive carcinomas multiplicity was reduced by ~74% to ~94% (p<0.0001) in OME exposed rats in comparison to the untreated rats. Biomarker analysis results showed a decrease in cell proliferation and anti-apoptotic/pro-survival proteins with an increase in apoptosis. Transcriptome analysis of treated tumors revealed a significant increase in adenocarcinoma inhibitory genes (Olmf4; Spink4) expression and down regulation of progression promoting genes (SerpinA1, MMP21, IL6). In summary, OME showed significant protection against the progression of adenoma to adenocarcinoma.

Current Status of Chemoprevention in Barrett's Esophagus

Candidates for chemoprevention in Barrett's esophagus have long been suggested and there has been observational data to support many drugs, including statins, hormone replacement therapy, metformin, proton pump inhibitor therapy, and aspirin. Proton pump inhibitor therapy and aspirin are the most promising agents. Data suggest that aspirin and proton pump inhibitor therapy can decrease the risk of neoplastic progression in Barrett's esophagus. Further, the combination of aspirin and proton pump inhibitor therapy decrease all-cause mortality by approximately 33%. Future guideline groups need to evaluate the evidence rigorously, but the combination of proton pump inhibitor therapy and aspirin is promising.

Is Malignant Potential of Barrett's Esophagus Predictable by Endoscopy Findings?

Given that endoscopic findings can be used to predict the potential of neoplastic progression in Barrett's esophagus (BE) cases, the detection rate of dysplastic Barrett's lesions may become higher even in laborious endoscopic surveillance because a special attention is consequently paid. However, endoscopic findings for effective detection of the risk of neoplastic progression to esophageal adenocarcinoma (EAC) have not been confirmed, though some typical appearances are suggestive. In the present review, endoscopic findings that can be used predict malignant potential to EAC in BE cases are discussed. Conventional results obtained with white light endoscopy, such as length of BE, presence of esophagitis, ulceration, hiatal hernia, and nodularity, are used as indicators of a higher risk of neoplastic progression. However, there are controversies in some of those findings. Absence of palisade vessels may be also a new candidate predictor, as that reveals degree of intense inflammation and of cyclooxygenase-2 protein expression with accelerated cellular proliferation. Furthermore, an open type of mucosal pattern and enriched stromal blood vessels, which can be observed by image-enhanced endoscopy, including narrow band imaging, have been confirmed as factors useful for prediction of neoplastic progression of BE because they indicate more frequent cyclooxygenase-2 protein expression along with accelerated cellular proliferation. Should the malignant potential of BE be shown predictable by these endoscopic findings, that would simplify methods used for an effective surveillance, because patients requiring careful monitoring would be more easily identified. Development in the near future of a comprehensive scoring system for BE based on clinical factors, biomarkers and endoscopic predictors is required.

DIAGNOSIS, TREATMENT AND FOLLOW-UP OF BARRETT'S ESOPHAGUS: A SYSTEMATIC REVIEW

BACKGROUND

Barrett's esophagus (BE) is a premalignant condition that raises controversy among general practitioners and specialists, especially regarding its diagnosis, treatment, and follow-up protocols.

OBJECTIVE

This systematic review aims to present the particularities and to clarify controversies related to the diagnosis, treatment and surveillance of BE.

METHODS

A systematic review was conducted on PubMed, Cochrane, and SciELO based on articles published in the last 10 years. PRISMA guidelines were followed and the search was made using MeSH and non-MeSH terms "Barrett" and "diagnosis or treatment or therapy or surveillance". We searched for complete randomized controlled clinical trials or Phase IV studies, carried out with individuals over 18 years old.

RESULTS

A total of 42 randomized controlled trials were selected after applying all inclusion and exclusion criteria. A growing trend of alternative and safer techniques to traditional upper gastrointestinal endoscopy were identified, which could improve the detection of BE and patient acceptance. The use of chromoendoscopy-guided biopsy protocols significantly reduced the number of biopsies required to maintain similar BE detection rates. Furthermore, the value of BE chemoprophylaxis with esomeprazole and acetylsalicylic acid was relevant, as well as the establishment of protocols for the follow-up and endoscopic surveillance of patients with BE based predominantly on the presence and degree of dysplasia, as well as on the length of the follow-up affected by BE.

CONCLUSION

Although further studies regarding the diagnosis, treatment and follow-up of BE are warranted, in light of the best evidence presented in the last decade, there is a trend towards electronic chromoendoscopy-guided biopsies for the diagnosis of BE, while treatment should encompass endoscopic techniques such as radiofrequency ablation. Risks of ablative endoscopic methods should be weighted against those of resective surgery. It is also important to consider lifetime endoscopic follow-up for both short and long term BE patients, with consideration to limitations imposed by a range of comorbidities. Unfortunately, there are no randomized controlled trials that have evaluated which is the best recommendation for BE follow-up and endoscopic surveillance (>1 cm) protocols, however, based on current International Guidelines, it is recommended esophagogastroduodenoscopy (EGD) every 5 years in BE without dysplasia with 1 up to 3 cm of extension; every 3 years in BE without dysplasia with >3 up to 10 cm of extension, every 6 to 12 months in BE with low grade dysplasia and, finally, EGD every 3 months after ablative endoscopic therapy in cases of BE with high grade dysplasia.

Chemoprevention of esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) is a major cause of cancer-related death, particularly in Western populations, and is rapidly rising in Asian populations at this time. Virtually all EACs develop from the precursor lesion Barrett's esophagus (BE), which is the most significant risk factor for EAC. However, the rates of progression from BE to EAC are low and patients with BE are asymptomatic. Thus, any strategy for EAC prevention must carry a low risk of harm in order to be clinically useful. Since current EAC-screening and BE-surveillance methods carry some procedural risk and are burdensome, there is an opportunity for chemoprevention, i.e. medications or dietary factors that may prevent BE from progressing to EAC. A variety of candidate chemoprevention therapies have been assessed to date. Proton-pump inhibitors (PPIs) are the best studied and have modest EAC-chemoprevention efficacy in BE patients, with a recent randomized trial showing that high-dose PPI may be more effective than low-dose PPI. Aspirin and other non-steroidal anti-inflammatory drugs have moderate quality observational and randomized-trial evidence for preventing progression of BE to EAC, but their risks for harm have precluded their routine clinical use. Other therapies (statins, metformin, female sex hormones) generally do not have strong evidence to support their use in EAC chemoprevention. Although progress has been made in this field, there is still a need for more effective and safe chemoprevention therapies for EAC.

Targeting the COX1/2-Driven thromboxane A2 pathway suppresses Barrett's esophagus and esophageal adenocarcinoma development

Background

Barrett's esophagus (BE), a complication of gastroesophageal reflux disease (GERD), predisposes patients to esophageal adenocarcinoma (EAC). Reliable biomarkers for early detection and discovery of potential drug targets are urgently needed for improved BE and EAC patient outcomes.

Methods

Patient biopsy samples were evaluated for COX1/2, and thromboxane A2 synthase (TBXAS) expression. Circulating prostaglandins biosynthesis was determined using enzyme immunoassay kits. Anchorage-independent cell growth assay, crystal violet staining assay, and xenograft experiments were conducted to assess BE and EAC cell growth. A surgical mouse model of reflux (i.e., esophagoduodenostomy) was established and samples were analyzed using an enzyme immunoassay kit, immunohistochemistry, immunoblotting, or RT-PCR. Esophageal biopsy samples (pre- and post-intervention) were obtained from a randomized clinical trial in which participants were administered esomeprazole (40 mg) twice daily in combination with an acetylsalicylic acid (ASA) placebo or 81 or 325 mg ASA for 28 days. Esophageal biopsy specimens before and after the intervention period were analyzed.

Findings

COX2 and TBXAS are highly expressed in BE and EAC patients accompanied by a pronounced elevation of circulating TXA2 levels. ASA suppressed BE and EAC growth by targeting the TXA2 pathway. Additionally, biopsies from 49 patients (with similar baseline characteristics) showed that ASA substantially decreased serum TXA2 levels, resulting in reduced inflammation.

Interpretation

This study establishes the importance of the COX1/2-driven TXA2 pathway in BE and EAC pathophysiology and lays the groundwork for introducing a TXA2-targeting strategy for EAC prevention and early detection.

Funding

Hormel Foundation, Exact Sciences, Pentax Medical, Intromedic and National Cancer.

Omeprazole prevents CDX2 and SOX9 expression by inhibiting hedgehog signaling in Barrett's esophagus cells

Activation of hedgehog (Hh) signaling contributes to the progression of Barrett's esophagus (BE), which increases the risk of esophageal adenocarcinoma. Recent clinical studies revealed that proton-pump inhibitors (PPIs) but not H2 receptor antagonists (H2RAs) were associated with a decreased risk of esophageal adenocarcinoma. We would like to know whether PPIs interfere with BE progression during BE treatment. Here, we explored the role of omeprazole on Hh signaling and expression of two crucial biomarkers of BE, SOX9 and CDX2. We demonstrated that bile acids elevated expression of Hh pathway target genes, such as GLI1 and PTCH1, and induced SOX9 and CDX2 up-regulation in both CP-A and CP-B cells. Omeprazole, but not famotidine, down-regulated these genes induced by bile acids. In addition, omeprazole-induced down-regulation of SOX9 and CDX2 was mediated by Hh signaling. To explore the mechanisms by which omeprazole inhibits Hh signaling, we performed luciferase assay but did not find any effects of omeprazole on the activity of GLI1 promoter, the critical transcription factor of Hh signaling. Therefore, we used miRNA sequencing and a bioinformatics tool in our study to identify the differently expressed miRNAs in BE organoids treated with or without omeprazole, and we identified miR-2116-3p was involved in omeprazole-mediated inhibition of Hh signaling and subsequent down-regulation of SOX9 and CDX2. Collectively, our data indicate omeprazole inhibits Hh signaling and subsequent SOX9 and CDX2 expression via up-regulating miR-2116-3p. We have demonstrated a novel acid-independent mechanism of omeprazole that might yield valuable insight into clinical management of BE progression, irrespective of acid reflux symptoms.

Chemoprevention of Barrett's Esophagus and Esophageal Adenocarcinoma

Barrett's esophagus is common in Western countries, but progression to esophageal adenocarcinoma is uncommon. Chemoprevention therefore needs to consider whether benefits outweigh risks given an otherwise healthy population. This will depend on the particular population at risk and the relative safety of a potential preventive agent. Most evidence regarding the potential benefit of chemoprevention of Barrett's esophagus and prevention of progression to esophageal adenocarcinoma is based on observational studies such as case-control and cohort studies. Given the potential benefits and relatively low risks, patients with BE should receive once-daily PPI therapy, but routine use of twice-daily PPI is not recommended unless necessitated by poor control of reflux symptoms or esophagitis. Recent data suggest that the inverse associations between aspirin/NSAID use and esophageal adenocarcinoma may be the result of reducing neoplastic progression (from metaplasia to dysplasia and carcinoma) rather than initiation of Barrett's esophagus. While substantial associative data suggest a potential benefit of aspirin and nonaspirin NSAIDs in reducing the risk of progression of Barrett's esophagus, the low risk of progression and the potential risks (gastrointestinal bleeding, complicated ulcer disease, hemorrhagic stroke) do not warrant routine use, unless dictated by cardiovascular risk. Chemoprevention after mucosal ablation in those at highest risk of post-ablation recurrence (dysplastic Barrett's) is currently under investigation.

Statistical controversies in clinical research: Value of adverse events relatedness to study treatment: analyses of data from randomized double-blind placebo-controlled clinical trials

Background

Collection and reporting of adverse events (AEs) and their relatedness to study treatment, known commonly as attribution, in clinical trials is mandated by regulatory agencies (the National Cancer Institute and the Food and Drug Administration). Attribution is assigned by the treating physician using judgment based on various factors including patient's baseline status, disease history, and comorbidity as well as knowledge about the safety profile of the study treatments. We evaluate the patterns of AE attribution (unrelated, unlikely, possibly, probably, and definitely related to the treatment) in treatment, symptom intervention (cancer patients) and cancer prevention (participants at high risk for cancer) setting.

Materials and methods

Nine multicenter placebo-controlled trials (two treatment, two symptom intervention, and five cancer prevention) were analysed separately (2155 patients). Frequency and severity of AEs were summarized by arm. Attribution and percentage of repeated AEs whose attribution changed overtime were summarized for the placebo arms. Percentage of physician over- or under-reporting of AE relatedness was calculated for the treatment arms using the placebo arm as the reference.

Results

Across all trials and settings, a very high proportion of AEs reported as related to treatment were classified as possibly related, a significant proportion of AEs in the placebo arm were incorrectly reported as related to treatment, and clinician-reported attribution over-estimated the rate of AEs related to treatment. Fatigue, nausea, vomiting, diarrhea, constipation, and neurosensory were the common AEs that were over reported by clinician as related to treatment.

Conclusions

These analyses demonstrate that assigning causality to AE is a complex and difficult process that produces unreliable and subjective data. In randomized double-blind placebo-controlled trials where data are available to objectively assess relatedness of AE to treatment, attribution assignment should be eliminated.

Omeprazole Inhibits Cell Proliferation and Induces G0/G1 Cell Cycle Arrest through Up-regulating miR-203a-3p Expression in Barrett's Esophagus Cells

Existing data suggest that proton pump inhibitors (PPIs), particularly omeprazole, have significant anti-tumor action in monotherapy and or combination chemotherapy. Hedgehog (Hh) signaling pathway represents a leading candidate as a molecular mediator of Barrett's esophagus (BE). Studies have indicated reduced miRNAs in BE progression, however, little is known about the latent anti-neoplasm effects of miRNAs in BE cells. Here, we investigated whether omeprazole could inhibit BE progression by regulating Hh pathway and explored the promising Hh-targeted miRNAs in BE cells. We conducted qRT-PCR and immunoblotting assay to evaluate the effects of omeprazole on the expression of Hh signaling components and miR-203a-3p in CP-A and CP-B cells. The promising target genes of miR-203a-3p were predicted by bioinformatics methods, and verified by luciferase assays and qRT-PCR. The effects of omeprazole on BE cell proliferation and cell cycle distribution were determined. The overexpression or silencing of miR-203a-3p was performed to test its anti-proliferative effects. Finally, rescue experiments that miR-203a-3p inhibitor alleviated the effects of omeprazole on decreasing the levels of Gli1 mRNA, protein and luciferase were performed. Mechanistic studies showed that omeprazole could inhibit the expression of Gli1 and the nuclear localization of Gli1. Moreover, we determined that omeprazole could selectively up-regulated the expression of miR-203a-3p, and Gli1 was a bona fide target of miR-203a-3p. miR-203a-3p inhibitor alleviated the suppressing effects of omeprazole on Gli1 luciferase activity, mRNA and protein level. The functional assay suggested that omeprazole could dose-dependently inhibit BE cell growth and induce cell cycle arrest in G0/G1 phase. Additionally, overexpression and silencing of miR-203a-3p in BE cells disrupted cell cycle progress, resulting in suppressing and accelerating cell proliferation, respectively. Taken together, these data provide a novel mechanism of potentially anti-neoplastic effects for omeprazole through modulation of miR-203a-3p expression and thus suppressing Hh/Gli1 signaling in BE cells.

A nonrandomized trial of vitamin D supplementation for Barrett's esophagus

Background

Vitamin D deficiency may increase esophageal cancer risk. Vitamin D affects genes regulating proliferation, apoptosis, and differentiation and induces the tumor suppressor 15-hydroxyprostaglandin dehydrogenase (PGDH) in other cancers. This nonrandomized interventional study assessed effects of vitamin D supplementation in Barrett’s esophagus (BE). We hypothesized that vitamin D supplementation may have beneficial effects on gene expression including 15-PGDH in BE.

Methods

BE subjects with low grade or no dysplasia received vitamin D₃ (cholecalciferol) 50,000 international units weekly plus a proton pump inhibitor for 12 weeks. Esophageal biopsies from normal plus metaplastic BE epithelium and blood samples were obtained before and after vitamin D supplementation. Serum 25-hydroxyvitamin D was measured to characterize vitamin D status. Esophageal gene expression was assessed using microarrays.

Results

18 study subjects were evaluated. The baseline mean serum 25-hydroxyvitamin D level was 27 ng/mL (normal ≥30 ng/mL). After vitamin D supplementation, 25-hydroxyvitamin D levels rose significantly (median increase of 31.6 ng/mL, p<0.001). There were no significant changes in gene expression from esophageal squamous or Barrett’s epithelium including 15-PGDH after supplementation.

Conclusion

BE subjects were vitamin D insufficient. Despite improved vitamin D status with supplementation, no significant alterations in gene expression profiles were noted. If vitamin D supplementation benefits BE, a longer duration or higher dose of supplementation may be needed.

Barrett’s oesophagus: Current controversies

Oesophageal adenocarcinoma is rapidly increasing in Western countries. This tumour frequently presents late in its course with metastatic disease and has a very poor prognosis. Barrett’s oesophagus is an acquired condition whereby the native squamous mucosa of the lower oesophagus is replaced by columnar epithelium following prolonged gastro-oesophageal reflux and is the recognised precursor lesion for oesophageal adenocarcinoma. There are multiple national and society guidelines regarding screening, surveillance and management of Barrett’s oesophagus, however all are limited regarding a clear evidence base for a well-demonstrated benefit and cost-effectiveness of surveillance, and robust risk stratification for patients to best use resources. Currently the accepted risk factors upon which surveillance intervals and interventions are based are Barrett’s segment length and histological interpretation of the systematic biopsies. Further patient risk factors including other demographic features, smoking, gender, obesity, ethnicity, patient age, biomarkers and endoscopic adjuncts remain under consideration and are discussed in full. Recent evidence has been published to support earlier endoscopic intervention by means of ablation of the metaplastic Barrett’s segment when the earliest signs of dysplasia are detected. Further work should concentrate on establishing better risk stratification and primary and secondary preventative strategies to reduce the risk of adenocarcinoma of the oesophagus.

A Review of the Novel Application and Potential Adverse Effects of Proton Pump Inhibitors

Proton pump inhibitors (PPIs) are known as a class of pharmaceutical agents that target H⁺/K⁺-ATPase, which is located in gastric parietal cells. PPIs are widely used in the treatment of gastric acid-related diseases including peptic ulcer disease, erosive esophagitis and gastroesophageal reflux disease, and so on. These drugs present an excellent safety profile and have become one of the most commonly prescribed drugs in primary and specialty care. Except for gastric acid-related diseases, PPIs can also be used in the treatment of Helicobacter pylori infection, viral infections, respiratory system diseases, cancer and so on. Although PPIs are mainly used short term in patients with peptic ulcer disease, nowadays these drugs are increasingly used long term, and frequently for a lifetime, for instance in patients with typical or atypical symptoms of gastroesophageal reflux disease and in NSAID or aspirin users at risk of gastrotoxicity and related complications including hemorrhage, perforation and gastric outlet obstruction. Long-term use of PPIs may lead to potential adverse effects, such as osteoporotic fracture, renal damage, infection (pneumonia and clostridium difficile infection), rhabdomyolysis, nutritional deficiencies (vitamin B12, magnesium and iron), anemia and thrombocytopenia. In this article, we will review some novel uses of PPIs in other fields and summarize the underlying adverse reactions.

Proton Pump Inhibitors Do Not Reduce the Risk of Esophageal Adenocarcinoma in Patients with Barrett's Esophagus: A Systematic Review and Meta-Analysis

Objectives

Proton pump inhibitors (PPIs) have been used for treatment of Barrett's esophagus (BE) for many years. However, the connection between PPIs and esophageal adenocarcinoma (EAC) in patients with BE has still been controversial. The current systematic review and meta-analysis was designed to evaluate the association between PPIs and the risk of EAC or high-grade dysplasia (HGD) in patients with BE.

Methods

A systematic literature search of studies reporting the association between PPIs and the risk of EAC and/or HGD in patients with BE was conducted in PubMed, Embase, Web of Science and the Cochrane Library. Next, literature was screened using previously established criteria and relevant data were extracted from included studies. Finally, the software program Review Manage 5.2 was applied to aggregate data and analyze the results.

Results

Nine observational studies, comprising five cohort and four case-control studies (including a total of 5712 patients with BE), were identified. Upon meta-analysis, PPIs were found to have no association with the risk of EAC and/or HGD in patients with BE (unadjusted OR 0.43, 95% CI 0.17–1.08). Analysis for duration response relationship revealed no significant trend toward protection against EAC or HGD with PPIs usage for >2~3 years (one study using 7-year cutoff) when compared to usage for shorter time periods (PPIs usage >2~3 years vs. <2~3 years: OR 0.91 (95% CI 0.25–3.31) vs. 0.91 (0.40–2.07)).There also was considerable heterogeneity between studies.

Conclusion

No dysplasia- or cancer-protective effects of PPIs usage in patients with BE were identified by our analysis. Therefore, we conclude that clinicians who discuss the potential chemopreventive effects of PPIs with their patients, should be aware that such an effect, if exists, has not been proven with statistical significance.

Esophageal Adenocarcinoma: The Influence of Medications Used to Treat Comorbidities on Cancer Prognosis

Esophageal adenocarcinoma has undergone a continuous rise in incidence since the early 1970s and is the fastest rising cancer among white men in the United States. Epidemiologic studies have demonstrated that medications commonly used to treat multiple chronic conditions (for example, aspirin, non-aspirin nonsteroidal anti-inflammatory drugs, and statins) as well as powerful acid suppressants such as proton pump inhibitors are associated with a reduced risk of esophageal adenocarcinoma. The chemopreventive potential of these classes of medications appears to be especially applicable to persons with Barrett's esophagus, the only known premalignant condition for esophageal adenocarcinoma. However, it is not known whether these medications also influence cancer recurrence and cancer-specific mortality in persons diagnosed with esophageal adenocarcinoma. This is an important question because most patients with esophageal adenocarcinoma have 1 or more comorbid conditions at the time of their cancer diagnosis and are receiving medication to treat these conditions. This article summarizes the evidence on the associations between 4 commonly used classes of medications and (1) risk of developing esophageal adenocarcinoma and Barrett's esophagus and (2) risk of cancer recurrence and cancer-specific mortality in patients with esophageal adenocarcinoma.

Recent developments in pathogenesis, diagnosis and therapy of Barrett's esophagus

The burden of illness from esophageal adenocarcinoma continues to rise in the Western world, and overall prognosis is poor. Given that Barrett’s esophagus (BE), a metaplastic change in the esophageal lining is a known cancer precursor, an opportunity to decrease disease development by screening and surveillance might exist. This review examines recent updates in the pathogenesis of BE and comprehensively discusses known risk factors. Diagnostic definitions and challenges are outlined, coupled with an in-depth review of management. Current challenges and potential solutions related to screening and surveillance are discussed. The effectiveness of currently available endoscopic treatment techniques, particularly with regards to recurrence following successful endotherapy and potential chemopreventative agents are also highlighted. The field of BE is rapidly evolving and improved understanding of pathophysiology, combined with emerging methods for screening and surveillance offer hope for future disease burden reduction.

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.

Strategy for prevention of cancers of the esophagus

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the animal reflux-inflammation models for Barrett's esophagus and esophageal adenocarcinoma; genomic/epigenomic analyses; eflornithine-based combinations; the molecular derangements that promote neoplastic transformation; the role of COX-2 inhibitors, proton pump inhibitors, and phase II trials in Barrett's adenocarcinoma; statins in chemoprevention and treatment of esophageal cancer; and biomarkers as potential targets in Barrett's adenocarcinoma.

Metformin does not reduce markers of cell proliferation in esophageal tissues of patients with Barrett's esophagus

BACKGROUND & AIMS

Obesity is associated with neoplasia, possibly via insulin-mediated cell pathways that affect cell proliferation. Metformin has been proposed to protect against obesity-associated cancers by decreasing serum insulin. We conducted a randomized, double-blind, placebo-controlled, phase 2 study of patients with Barrett's esophagus (BE) to assess the effect of metformin on phosphorylated S6 kinase (pS6K1), a biomarker of insulin pathway activation.

METHODS

Seventy-four subjects with BE (mean age, 58.7 years; 58 men [78%; 52 with BE >2 cm [70%]) were recruited through 8 participating organizations of the Cancer Prevention Network. Participants were randomly assigned to groups given metformin daily (increasing to 2000 mg/day by week 4, n = 38) or placebo (n = 36) for 12 weeks. Biopsy specimens were collected at baseline and at week 12 via esophagogastroduodenoscopy. We calculated and compared percent changes in median levels of pS6K1 between subjects given metformin vs placebo as the primary end point.

RESULTS

The percent change in median level of pS6K1 did not differ significantly between groups (1.4% among subjects given metformin vs -14.7% among subjects given placebo; 1-sided P = .80). Metformin was associated with an almost significant reduction in serum levels of insulin (median -4.7% among subjects given metformin vs 23.6% increase among those given placebo, P = .08) as well as in homeostatic model assessments of insulin resistance (median -7.2% among subjects given metformin vs 38% increase among those given placebo, P = .06). Metformin had no effects on cell proliferation (on the basis of assays for KI67) or apoptosis (on the basis of levels of caspase 3).

CONCLUSIONS

In a chemoprevention trial of patients with BE, daily administration of metformin for 12 weeks, compared with placebo, did not cause major reductions in esophageal levels of pS6K1. Although metformin reduced serum levels of insulin and insulin resistance, it did not discernibly alter epithelial proliferation or apoptosis in esophageal tissues. These findings do not support metformin as a chemopreventive agent for BE-associated carcinogenesis. ClinicalTrials.gov number, NCT01447927.

Barrett's oesophagus: frequency and prediction of dysplasia and cancer

The incidence of oesophageal adenocarcinoma is continuing to increase at an alarming rate in the Western world today. Barrett's oesophagus is a clearly recognized risk factor for the development of oesophageal adenocarcinoma, but the overwhelming majority of patients with Barrett's oesophagus will never develop oesophageal cancer. A number of endoscopic, histologic and epidemiologic risk factors identify Barrett's oesophagus patients at increased risk for progression to high-grade dysplasia and oesophageal adenocarcinoma. Endoscopic factors include segment length, mucosal abnormalities as seemingly trivial as oesophagitis and the 12 to 6 o'clock hemisphere of the oesophagus. Both intestinal metaplasia and low grade dysplasia, the latter only if confirmed by a pathologist with expertise in Barrett's oesophagus pathologic interpretation are the histologic risk factors for progression. Epidemiologic risk factors include ageing, male gender, obesity, and smoking. Factors that may protect against the development of adenocarcinoma include a diet rich in fruits and vegetables, and the use of proton pump inhibitors, aspirin/NSAIDs and statins.

Chemoprevention in Barrett's oesophagus

Increasing incidence of oesophageal adenocarcinoma along with poor survival entails novel preventive strategies. Agents that target pro-oncogenic pathways in Barrett's mucosa could halt this neoplastic transformation. In this review, we will use epidemiological associations and molecular mechanisms to identify novel chemoprevention targets in Barrett's oesophagus. We will also discuss recent chemoprevention trials.

NSAIDs, statins, low-dose aspirin and PPIs, and the risk of oesophageal adenocarcinoma among patients with Barrett's oesophagus: a population-based case-control study

OBJECTIVES

Non-steroidal anti-inflammatory drugs (NSAIDs), proton pump inhibitors (PPIs), low-dose aspirin and statins may decrease the risk of oesophageal adenocarcinoma (OAC) among patients with Barrett's oesophagus (BO). However, previous studies did not adequately address bias and confounding. Our objective was to estimate the risk of OAC among patients with BO exposed to NSAIDs, statins and PPIs.

DESIGN

Case-control study nested within a BO cohort.

SETTING

Two primary care databases (the UK and the Netherlands (NL)).

PARTICIPANTS

Cases were adults ≥18 years of age with OAC or high-grade dysplasia (HGD) diagnosis ≥1 year after BO diagnosis. Controls were matched on age, sex, year of BO diagnosis and database.

EXPOSURE

Drug use was assessed from BO diagnosis until matching date.

OUTCOME MEASURE

Adjusted ORs with 95% CI were calculated by conditional logistic regression.

RESULTS

Within the BO cohort (n=15 134), 45 OAC (UK: 40, NL: 5) and 12 HGD cases (NL: 12) were identified. ORa for OAC during NSAID use was 1.2 (95% CI 0.6 to 2.5) and during statin use for >3 years 0.5 (95% CI 0.1 to 1.7). When including HGD cases (n=57), ORa for NSAID use was 0.9 (95% CI 0.5 to 1.8) and for statin use >3 years 0.5 (95% CI 0.1 to 1.7). Higher doses of statins showed lower estimates for OAC and HGD, though not statistically significant. Low-dose aspirin and PPIs did not significantly decrease the risk of OAC and HGD.

CONCLUSIONS

In this population-based nested case-control study, use of NSAIDs, PPIs, low-dose aspirin or statins did not reduce the risk of HGD and OAC among patients with BO. These findings indicate that for an unselected group of patients with BO chemoprevention by use of drugs to reduce progression to HGD and OAC should not be directly considered as routine care.

Preference of endoscopic ablation over medical prevention of esophageal adenocarcinoma by patients with Barrett's esophagus

BACKGROUND & AIMS

Endoscopic intervention or pharmacologic inhibition of cyclooxygenase might be used to prevent progression of Barrett's esophagus (BE) to esophageal adenocarcinoma (EAC). We investigated whether patients with BE prefer endoscopic therapy or chemoprevention of EAC.

METHODS

Eighty-one subjects with nondysplastic BE were given a survey that described 2 scenarios. The survey explained that treatment A (ablation), endoscopy, reduced lifetime risk of EAC by 50%, with 5% risk for esophageal stricture, whereas treatment B (aspirin) reduced lifetime risk of EAC by 50% and the risk of heart attack by 30%, yet increased the risk for ulcer by 75%. Subjects indicated their willingness to undergo either treatment A and/or treatment B if endoscopic surveillance were required every 3-5 years, every 10 years, or were not required. Visual aids were included to represent risk and benefit percentages.

RESULTS

When surveillance was required every 3-5 years, more subjects were willing to undergo treatment A than treatment B (78%, 63 of 81 vs 53%, 43 of 81; P < .01). There were no differences in age, sex, education level, or history of cancer, heart disease, or ulcer between patients willing to undergo treatment A and those willing to undergo treatment B. Altering the frequency of surveillance did not affect patients' willingness to undergo either treatment.

CONCLUSIONS

In a simulated scenario, patients with BE preferred endoscopic intervention over chemoprevention for EAC. Further investigation of the shared decision-making process regarding preventive strategies for patients with BE may be warranted.

The prevalence of Barrett's-esophagus-associated dysplasia in Puerto Rico

OBJECTIVE

Barrett's esophagus (BE) is the strongest risk factor of esophageal adenocarcinoma (EAC). A previous study found a lower incidence of EAC in Puerto Rico (PR) as compared to other racial/ethnic groups in the United States (US). Notwithstanding, BE epidemiology in PR is unknown. Study aims: i) to determine BE prevalence among individuals with gastroenterological pathology reports from three major anatomic pathology laboratories in PR and ii) to describe the association between dysplastic BE with age and gender.

METHODS

Clinic-based study examined data collected from three anatomic pathology laboratories encompassing the majority of gastroenterology practices in PR. Individuals with histology confirmed BE (January 2007-December 2011) were analyzed (n = 1,232). We estimated BE prevalence and adjusted odds ratios (AOR) to assess magnitude of association between dysplastic BE with age and gender using logistic regression models.

RESULTS

Overall BE prevalence was 4.4% (95% CI = 4.1-4.6). Most BE patients were males (male-to-female ratio = 2.3:1) with mean age of 64 ± 13 years. Ninety one percent of BE biopsies showed no dysplasia whereas 6.2% had EAC. BE patients age > 74 years had an increased risk of EAC (AOR: 2.38, 95% CI = 1.14-4.94) compared to those < 55 years old. Males had increased EAC risk (AOR: 2.23, 95% CI = 1.23-4.06) compared to females.

CONCLUSION

BE prevalence in PR is similar to that of non-Hispanic whites and Hispanics in US. The lower occurrence of dysplastic BE in PR could explain EAC incidence disparities between PR and other groups in the US.

Molecular markers and imaging tools to identify malignant potential in Barrett's esophagus

Due to its rapidly rising incidence and high mortality, esophageal adenocarcinoma is a major public health concern, particularly in Western countries. The steps involved in the progression from its predisposing condition, gastroesophageal reflux disease, to its premalignant disorder, Barrett’s esophagus, and to cancer, are incompletely understood. Current screening and surveillance methods are limited by the lack of population-wide utility, incomplete sampling of standard biopsies, and subjectivity of evaluation. Advances in endoscopic ablation have raised the hope of effective therapy for eradication of high-risk Barrett’s lesions, but improvements are needed in determining when to apply this treatment and how to follow patients clinically. Researchers have evaluated numerous potential molecular biomarkers with the goal of detecting dysplasia, with varying degrees of success. The combination of biomarker panels with epidemiologic risk factors to yield clinical risk scoring systems is promising. New approaches to sample tissue may also be combined with these biomarkers for less invasive screening and surveillance. The development of novel endoscopic imaging tools in recent years has the potential to markedly improve detection of small foci of dysplasia in vivo. Current and future efforts will aim to determine the combination of markers and imaging modalities that will most effectively improve the rate of early detection of high-risk lesions in Barrett’s esophagus.

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.

Barrett's esophagus and cancer risk: how research advances can impact clinical practice

Barrett’s esophagus (BE) is the only known precursor to esophageal adenocarcinoma (EAC), whose incidence has increased sharply in the last 4 decades. The annual conversion rate of BE to cancer is significant, but small. The identification of patients at a higher risk of cancer therefore poses a clinical conundrum. Currently, endoscopic surveillance is recommended in BE patients, with the aim of diagnosing either dysplasia or cancer at early stages, both of which are curable with minimally invasive endoscopic techniques. There is a large variation in clinical practice for endoscopic surveillance, and dysplasia as a marker of increased risk is affected by sampling error and high interobserver variability. Screening programs have not yet been formally accepted, mainly due to the economic burden that would be generated by upper gastrointestinal endoscopy. Screening programs have not yet been formally accepted, mainly due to the economic burden that would be generated by widespread indication to upper gastrointestinal endoscopy. In fact, it is currently difficult to formulate an accurate algorithm to confidently target the population at risk, based on the known clinical risk factors for BE and EAC. This review will focus on the clinical and molecular factors that are involved in the development of BE and its conversion to cancer and on how increased knowledge in these areas can improve the clinical management of the disease.

Chemopreventive strategies in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third most common cause of death from cancer. The incidence and mortality of HCC are increasing in most Western countries as a result of an ageing cohort infected with chronic hepatitis C, and are expected to continue to rise as a consequence of the obesity epidemic. Chemopreventive strategies aimed at decreasing the risk or delaying the onset of HCC are needed. Universal immunization against HBV and antiviral therapy against HBV and HCV in patients with established disease has consistently been associated with reduced HCC risk, especially in patients who achieve sustained virologic response. However, the cost-effectiveness of antiviral therapy for primary HCC prevention is not known. Several commonly prescribed medications seem promising as chemopreventive agents against HCC, including statins, antidiabetic medications and aspirin. Dietary agents such as coffee, vitamin E and fish oil as well as phytochemicals might also be associated with reduced risk of HCC. Though randomized controlled trials are ideally needed to firmly establish efficacy, such chemoprevention trials are logistically and ethically challenging. Well-designed, prospective, population-based cohort studies might provide the best evidence for chemopreventive efficacy of these agents.

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.

Chemoprevention of gastrointestinal neoplasia

Cancer chemoprevention is defined as the pharmacologic intervention, by drugs or nutrient-components, with the process of carcinogenesis, in order to prevent the development of invasive malignant neoplasms. This preventive attempt is particularly challenging in cancer types, which have a long subclinical developmental phase, because of their low cellular proliferation rate and their slow pre-clinical evolution, until they become clinically detectable and therapeutically as well as prognostically relevant. Therefore, only certain specific cancer types are presently in the focus of clinical chemoprevention. Among the GI tract cancer, colorectal (CRC) as well as esophageal cancer have raised the most attention over the past decades, as they both share a long precancerous stage (the adenoma in CRC and Barrett's esophagus in the case of esophageal adenocarcinoma) which provides a window of opportunity to intervene and prevent development of cancer.In this review, we will focus on both CRC as well as esophageal adenocarcinoma (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.

Recent developments in esophageal adenocarcinoma

Answer questions and earn CME/CNE Esophageal adenocarcinoma (EAC) is characterized by 6 striking features: increasing incidence, male predominance, lack of preventive measures, opportunities for early detection, demanding surgical therapy and care, and poor prognosis. Reasons for its rapidly increasing incidence include the rising prevalence of gastroesophageal reflux and obesity, combined with the decreasing prevalence of Helicobacter pylori infection. The strong male predominance remains unexplained, but hormonal influence might play an important role. Future prevention might include the treatment of reflux or obesity or chemoprevention with nonsteroidal antiinflammatory drugs or statins, but no evidence-based preventive measures are currently available. Likely future developments include endoscopic screening of better defined high-risk groups for EAC. Individuals with Barrett esophagus might benefit from surveillance, at least those with dysplasia, but screening and surveillance strategies need careful evaluation to be feasible and cost-effective. The surgery for EAC is more extensive than virtually any other standard procedure, and postoperative survival, health-related quality of life, and nutrition need to be improved (eg, by improved treatment, better decision-making, and more individually tailored follow-up). Promising clinical developments include increased survival after preoperative chemoradiotherapy, the potentially reduced impact on health-related quality of life after minimally invasive surgery, and the new endoscopic therapies for dysplastic Barrett esophagus or early EAC. The overall survival rates are improving slightly, but poor prognosis remains a challenge.