Barrett's esophagus. Reducing the risk of progression to adenocarcinoma

Gold nanorods and curcumin-loaded nanomicelles for efficient in vivo photothermal therapy of Barrett's esophagus

Aim: Provide an enhanced local drug delivery, nanoparticle(s) to minimize systemic effects and achieve enhanced permeability and drug retention into abnormal cells and stroma. Materials & methods: Here a simultaneous loading of lipophilic gold nanorods (GNRs) and curcumin into polymeric nanomicelles made of biocompatible PLGA-b-PEG copolymer through a double re-emulsification process has been developed. Results: Initial results in vitro on Barrett's esophagus and esophageal adenocarcinoma cell lines demonstrated a significant reduction in cell viability with curcumin and GNRs exposure (p < 0.05). In vivo Barrett's-associated animal model confirmed these results with successful in vivo demonstrated eradication of all high-grade dysplastic premalignant cancer cells. Conclusion: The synthesis of this novel nanosystem containing GNRs and curcumin is safe and effective in treating and eradicating premalignant esophageal adenocarcinoma.

Dietary freeze-dried black raspberry's effect on cellular antioxidant status during reflux-induced esophagitis in rats

INTRODUCTION

Esophageal cancer consists of two distinct types, esophageal adenocarcinoma (EAC) and squamous cell carcinoma, both of which differ significantly in their etiology. Freeze-dried black raspberry (BRB) has been consistent in its ability to modulate the biomarkers and reduce the incidence of carcinogen-induced squamous cell carcinoma in rats. In our previous studies in the esophagoduodenal anastomosis (EDA) model, we have shown that the early modulation of manganese superoxide dismutase (MnSOD) significantly correlates with the development of reflux-induced EAC in rats. In this study we looked at the short-term effects of a BRB-supplemented diet on the modulation of antioxidant enzymes in reflux-induced esophagitis.

METHODS

Male SD rats (8 wk old; n = 3-5) were randomized into three groups--sham-operated, fed control AIN-93M diet (SH-CD), EDA operated and fed either control diet (EDA-CD) or 2.5% (w/w) BRB diet (EDA-BRB). The effect of both reflux and dietary supplementation was analyzed 2 and 4 wk after EDA surgery.

RESULTS

Animals in the EDA groups had significantly lower weight gain and diet intake compared to SH-CD (P < 0.05). The sham-operated animals received an average esophagitis score of 0.1 ± 0.1; this increased significantly in EDA-CD animals to 1.8 ± 0.14 (P < 0.001 versus SH-CD) and in EDA-BRB group to 1.7 ± 0.06 (P < 0.001 versus SH-CD), with BE changes also present. However, dietary supplementation of BRB did not alter or ameliorate the grade of esophagitis or the induction of BE. BRB diet caused a 43% increase in MnSOD levels compared to EDA-CD (0.73 ± 0.16; P = 0.09); however, this effect was not statistically significant and at 4 wk, EDA-CD (0.58 ± 0.12) showed an increase in MnSOD expression compared to SH-CD (0.34 ± 0.01).

CONCLUSIONS

In conclusion, our data suggest that dietary BRB does not increase the levels of cellular antioxidant enzymes or reduce the levels of lipid peroxidation compared to a control diet, in a short-term study of gastroesophageal reflux induction in the EDA animal model. However, it remains to be tested whether this is indicative of its ineffectiveness to inhibit reflux-induced EAC incidence over the long term.

Beyond Field Effect: Analysis of Shrunken Centroids in Normal Esophageal Epithelia Detects Concomitant Esophageal Adenocarcinoma

BACKGROUND AND AIMS: Because of the extremely low neoplastic progression rate in Barrett's esophagus, it is difficult to diagnose patients with concomitant adenocarcinoma early in their disease course. If biomarkers existed in normal squamous esophageal epithelium to identify patients with concomitant esophageal adenocarcinoma, potential applications would be far-reaching. The aim of the current study was to identify global gene expression patterns in normal esophageal epithelium capable of revealing simultaneous esophageal adenocarcinoma, even located remotely in the esophagus. METHODS: Tissues comprised normal esophageal epithelia from 9 patients with esophageal adenocarcinoma, 8 patients lacking esophageal adenocarcinoma or Barrett's, and 6 patients with Barrett's esophagus alone. cDNA microarrays were performed, and pattern recognition in each of these subgroups was achieved using shrunken nearest centroid predictors. RESULTS: Our method accurately discriminated normal esophageal epithelia of 8/8 patients without esophageal adenocarcinoma or Barrett's esophagus and of 6/6 patients with Barrett's esophagus alone from normal esophageal epithelia of 9/9 patients with Barrett's esophagus and concomitant esophageal adenocarcinoma. Moreover, we identified genes differentially expressed between the above subgroups. Thus, based on their corresponding normal esophageal epithelia alone, our method accurately diagnosed patients who had concomitant esophageal adenocarcinoma. CONCLUSIONS: These global gene expression patterns, along with individual genes culled from them, represent potential biomarkers for the early diagnosis of esophageal adenocarcinoma from normal esophageal epithelia. Genes discovered in normal esophagus that are differentially expressed in patients with vs. without esophageal adenocarcinoma merit further pursuit in molecular genetic, functional, and therapeutic interventional studies.

Met receptor signaling: a key effector in esophageal adenocarcinoma

PURPOSE

The incidence of esophageal adenocarcinoma is rising, and survival rates remain poor. The hepatocyte growth factor (HGF) receptor Met has been detected in esophageal cancer. The perturbation of cadherin/catenin complexes has also been shown. We sought to investigate a link among Met expression, cadherin/catenin biology, and cell growth. We assessed the prognostic significance of Met expression in esophageal adenocarcinoma.

EXPERIMENTAL DESIGN

Met and HGF expression in esophageal tissues were assessed using immunohistochemistry and ELISA. Met-positive cell lines (OE33 and SEG1) and a Met-negative cell line (TE7) were incubated with HGF. Real-time reverse transcription-PCR and Western blotting were used to assess levels of E-cadherin expression. Nuclear TCF/beta-catenin signaling was assessed following reporter construct transfection. Agar colony formation was used to assess anchorage-independent growth. A panel of 72 resected esophageal adenocarcinomas were assessed for Met expression by immunohistochemistry and correlated to survival data.

RESULTS

An increased expression of Met was seen along the metaplasia- adenocarcinoma sequence. Met-positive cells showed reductions in E-cadherin mRNA (37% and 69%) and protein expression following stimulation with HGF (P < 0.01). OE33 and SEG-1 showed up to a 2-fold increase in the levels of beta-catenin nuclear signaling (P < 0.01). TE7 only responded when transfected to express Met; E-cadherin expression decreased by 64% (P < 0.01). HGF stimulation led to increased agar colony formation (P < 0.01). Patients with Met-positive tumors showed lower 6-month survival rates after surgical resection than those with Met-negative tumors (P < 0.05).

CONCLUSIONS

Met activation induces changes consistent with early invasion, such as down-regulation of E-cadherin, increased nuclear TCF/beta-catenin signaling, and anchorage-independent growth. This is supported by ex vivo data associating Met with reduced short-term survival. Inhibitors of Met may be effective treatment for esophageal adenocarcinoma.

Review article: the patient with gastro-oesophageal reflux disease--lifestyle advice and medication

Gastro-oesophageal reflux disease (GERD) is a highly prevalent disorder in all Western countries. Interestingly, prevalence rates appear to be increasing in these countries, with a remarkable increase of GERD-related lethal and nonlethal complications. However, these complications are rare on a global scale. This review aims to summarize the current concepts of genetic, lifestyle and environmental factors that need to be considered whilst caring for patients with these disorders. GERD is defined by the augmented exposure of oesophageal mucosa to acidic content, and is associated with specific symptoms or mucosal lesions. A number of factors may contribute to the manifestation of GERD. Although recent studies emphasize the role of genetic factors, there are many other risk factors that play a pivotal role in the development of GERD and GERD complications. Some nutritional factors are believed to aggravate acidic reflux either by delaying gastric emptying or diminishing the pressure of the lower oesophageal sphincters. Patients are often advised to sleep with their heads elevated, but this advice is not easy to follow and has not been proven effective with regard to long-term outcome. Other lifestyle modifications include changes to the patient's diet, which are important but not frequently sufficient. Thus, medication is usually necessary for symptom control. Proton pump inhibitors are now mainstream treatment for the reduction of acid secretion in patients with severe manifestations and 4-week healing rates are approaching 90%.

Comparison of interobserver agreement for different scoring systems for reflux esophagitis: Impact of level of experience

BACKGROUND

The Savary-Miller, the Los Angeles, and the MUSE (metaplasia, ulcer, stricture, erosion) scoring systems have been developed to assess esophageal lesions related to GERD. Interobserver agreement for these systems was compared, with particular reference to the experience of the endoscopist.

METHODS

By using videoendoscopes, videotapes were made of the gastroesophageal junction of 60 patients who presented with symptoms suggestive of GERD. The Savary-Miller, the Los Angeles, and the MUSE systems were used to score all video clips by 9 endoscopists who were subgrouped by level of experience (3 levels, 3 endoscopists per level). Agreement was assessed by using weighted kappa statistics (kappa).

RESULTS

The Savary-Miller scoring system revealed moderate agreement for the experienced group (kappa=0.41) but performed poorly when applied by inexperienced raters (kappa=0.16). The Los Angeles system was most reproducible in all subgroups, irrespective of the level of experience (kappa=0.49 to 0.65). The MUSE scoring system was highly similar to the Los Angeles scoring system with respect to erosions and, in addition, allowed assessment of complications of GERD.

CONCLUSIONS

The Los Angeles and the MUSE scoring systems are most reliable for the assessment of erosions caused by GERD. Because of low reliability, use of the Savary-Miller scoring system is not recommended. For all scoring systems, interobserver agreement varies with the level of experience in the performance of upper endoscopy.

Review article: screening and surveillance of Barrett's oesophagus: what is a cost-effective framework?

There is a strong association between symptomatic gastro-oesophageal reflux and oesophageal adenocarcinoma. With this in mind, the American College of Gastroenterology has recently revised its practice guidelines for the screening of patients with chronic gastro-oesophageal reflux disease (GERD) to identify those at risk of oesophageal adenocarcinoma, and recommends surveillance to identify curable oesophageal neoplasms in patients with established Barrett's oesophagus. Patients with chronic GERD symptoms, particularly those aged over 50 years, should undergo upper endoscopy. Patients found to have Barrett's oesophagus should be treated with acid suppression for GERD symptoms and then undergo regular surveillance endoscopy. Surveillance endoscopy every 3 years is recommended for those without dysplasia. For patients with verified low-grade dysplasia, yearly surveillance endoscopy is recommended. For those with focal high-grade dysplasia (defined as high-grade dysplastic changes involving fewer than five crypts), the condition may be followed with endoscopic surveillance performed at 3-month intervals. If there is verified, multifocal high-grade dysplasia, intervention (e.g. oesophagectomy) may be considered. Both observational and computer models suggest a benefit associated with screening and surveillance. Endoscopic screening and surveillance for Barrett's oesophagus compares favourably with mammography for the detection of breast cancer and other accepted medical practices.

Curing oesophageal cancer: one swallow does not make a summer

The mainstay of curative treatment for oesophageal cancer is currently surgery with neoadjuvant chemotherapy or radiotherapy. In most cases, single-agent chemotherapy has been disappointing and allows the development of resistant cancer cells. Success is more likely with combination therapy, although toxicity may be higher. Ifosfamide is generally no different in this respect, but the report of a complete cure in a case treated solely by ifosfamide is discussed. Such subgroup patients may be important in helping to identify factors that predict the biological behaviour of oesophageal cancers, and may aid us in the search for specific markers of treatment response.

Childhood gastroesophageal reflux symptoms in adult patients

OBJECTIVES

Gastroesophageal reflux (GER) and its esophageal (esophagitis, Barrett's esophagus) and extraesophageal (asthma, laryngeal disease) disease manifestations (GERD) are increasing common problems in children and adults. There are virtually no published longitudinal outcome studies that describe the natural history of childhood-onset GER throughout a person's lifetime. The aim of this study was to compare the frequency of recalled childhood reflux symptoms in adult patients currently with and without GER symptoms.

METHODS

Four hundred adult patients were classified as refluxers (225 patients; 57%), nonrefluxers (154 patients; 38%), and those who claimed to not know if they had reflux (21 patients; 5%; excluded from analysis). Subjects were given a questionnaire asking them to recall childhood symptoms attributed to GER. Of the 225 refluxers, 141 (63%) recalled at least one childhood symptom, compared with 54 of the 154 nonrefluxers (35%) ( < 0.001).

CONCLUSIONS

Adult refluxers were more likely to recall having developed GER symptoms at an earlier age, beginning at infancy and developing statistically significant GER compared with nonrefluxers after age 11. Adults suffering from GER were far more likely than nonrefluxers to recall having experienced GER symptoms during childhood. Well-designed, population-based epidemiologic studies are needed to more accurately assess the extent of GER in the overall population and the extent of its impact on health care in the United States.

Innovative endoscopic mapping technique of Barrett's mucosa

Barrett's esophagus is the most common premalignant lesion of the upper gastrointestinal tract. This metaplastic change in the normal esophageal epithelium occurs in 10% to 15% of patients with chronic reflux esophagitis and is associated with a 30- to 40-fold increased risk of developing esophageal cancer. Cancers of the esophagus and gastroesophageal junction are increasing in incidence faster than any other cancer in the Western world. Despite the importance of this cancer epidemic and its well-known precursor lesion, most investigators have taken a subjective approach to quantifying the extent of disease, the location of abnormal tissues, and the effect of ablation techniques. Our ability to impact on this epidemic may be dependent on our ability to apply modern technologies to document quantitatively both the extent of disease and the severity of molecular derangement of the intrinsic growth regulatory mechanism of the metaplastic cells. This review will focus on the challenge of addressing the quantitative endoscopic findings in Barrett's esophagus.

The treatment, management and prevention of oesophageal cancer

The combination of a rising incidence and a poor survival rate makes oesophageal cancer a major health issue. Adenocarcinoma of the oesophagus is associated with one of the commonest pre-malignant lesions recognised, Barrett's metaplasia. This provides a focus for early detection and intervention. The subjects of acid suppression, bile reflux, COX-2 inhibition and ablation therapy will be discussed herewith. Established carcinoma is now rarely treated by surgery alone and this review discusses the benefits of multimodality therapy combined with more accurate staging techniques. Finally an emerging understanding of the molecular events that characterise the transition to carcinoma may provide novel targets in cancer therapy such as epidermal growth factor receptor (EGFR) and TNF-alpha. This review will focus on some of the future developments in the treatment of oesophageal cancer.

Tumor cell death induced by topoisomerase-targeting drugs

DNA topoisomerases are double-edged swords. They are essential for many vital functions of DNA during normal cell growth. However, they are also highly vulnerable under various physiological and nonphysiological stresses because of their delicate act on breaking and rejoining DNA. These stresses (e.g. exposure to topoisomerase poisons, acidic pH, and oxidative stresses) can convert DNA topoisomerases into DNA-breaking nucleases, resulting in cell death and/or genomic instability. The importance of topoisomerase-mediated DNA cleavage in tumor cell death and carcinogenesis has been recognized. This review focuses on recent findings concerning the molecular mechanisms of the stress responses to topoisomerase-mediated DNA damage. The involvement of ubiquitin/26S proteasome and SUMO/UBC9 in these processes, as well as the role of topoisomerase cleavable complexes in apoptotic cell death are discussed.