Management of nondysplastic Barrett's esophagus: where are we now?

Upregulation of mucin glycoprotein MUC1 in the progression to esophageal adenocarcinoma and therapeutic potential with a targeted photoactive antibody-drug conjugate

BACKGROUND

Mucin glycoprotein 1 (MUC1) is a glycosylated transmembrane protein on epithelial cells. We investigate MUC1 as a therapeutic target in Barrett's epithelium (BE) and esophageal adenocarcinoma (EA) and provide proof of concept for a light based therapy targeting MUC1.

RESULTS

MUC1 was present in 21% and 30% of significantly enriched pathways comparing BE and EA to squamous epithelium respectively. MUC1 gene expression was x2.3 and x2.2 higher in BE (p=<0.001) and EA (p=0.03). MUC1 immunohistochemical expression increased during progression to EA and followed tumor invasion. HuHMFG1 based photosensitive antibody drug conjugates (ADC) showed cell internalization, MUC1 selective and light-dependent cytotoxicity (p=0.0006) and superior toxicity over photosensitizer alone (p=0.0022).

METHODS

Gene set enrichment analysis (GSEA) evaluated pathways during BE and EA development and quantified MUC1 gene expression. Immunohistochemistry and flow cytometry evaluated the anti-MUC1 antibody HuHMFG1 in esophageal cells of varying pathological grade. Confocal microscopy examined HuHMFG1 internalization and HuHMFG1 ADCs were created to deliver a MUC1 targeted phototoxic payload.

CONCLUSIONS

MUC1 is a promising target in EA. Molecular and light based targeting of MUC1 with a photosensitive ADC is effective in vitro and after development may enable treatment of locoregional tumors endoscopically.

Endoscopic Therapy of Early Carcinoma of the Oesophagus

Background

Oesophageal cancer is a comparatively rare disease in the Western world. Prognosis is highly dependent on the choice of treatment. Early stages can be treated by endoscopic resection, whereas surgery needs to be performed in the case of advanced carcinomas. Technical progress has enabled high-definition endoscopes and technical add-ons which help the endoscopist in finding fine irregularities in the oesophageal mucosa, though interpretation still remains challenging.

Methods

In this review, we discuss both novel and old diagnostic procedures and their value, as well as the current recommendations for the diagnosis and treatment of early oesophageal carcinomas. The database of PubMed and Medline was searched and analysed to provide all relevant literature for this review.

Results and Conclusion

Endoscopic resection is the therapy of choice in early oesophageal cancer. In case of adenocarcinoma it is mandatory to perform subsequent ablation of all residual Barrett's mucosa to avoid metachronous lesions.

Current issues in Barrett's esophagus and Barrett's-related dysplasia

Surgical pathologists frequently encounter biopsies in patients with Barrett's esophagus (BE), defined as replacement of the normal stratified squamous epithelium of the distal esophagus by metaplastic columnar epithelium containing goblet cells. Thus, one of the primary roles of the pathologist is to definitively identify goblet cells, best done on routine stained sections. It has recently been questioned as to whether goblet cells should be absolutely necessary to render a diagnosis of BE, given immunohistochemical and flow cytometric similarities between columnar-lined esophagus with and without goblet cells. Once a diagnosis of BE is rendered, the pathologist must state, using a simple classification, whether the biopsy is negative for dysplasia or shows dysplasia (low-grade dysplasia or high-grade dysplasia). However, there are a number of known pitfalls in distinguishing dysplasia from reactive epithelium, and it can be similarly difficult to distinguish low-grade dysplasia from high-grade dysplasia. In addition, there are some cases in which the distinction of high-grade dysplasia from intramucosal adenocarcinoma can be challenging. All of these issues are summarized in this paper.

Confocal laser endomicroscopy for in vivo diagnosis of Barrett's oesophagus and associated neoplasia: a pilot study conducted in a single Italian centre

BACKGROUND

Diagnosis and management of Barrett's oesophagus are controversial. Technical improvements in real-time recognition of intestinal metaplasia and neoplastic foci provide the chance for more effective target biopsies. Confocal laser endomicroscopy allows to analyze living cells during endoscopy.

AIMS

To assess the diagnostic accuracy, inter- and intra-observer variability of endomicroscopy for detecting in vivo neoplasia (dysplasia and/or early neoplasia) in Barrett's oesophagus.

METHODS

Prospective pilot study. Patients referred for known Barrett's oesophagus were screened. Endomicroscopy was carried out in a circular fashion, every 1-2 cm, on the whole columnar-lined distal oesophagus. Visible lesions, when present, were analyzed first. Targeted biopsies were taken. Confocal images were classified according to confocal Barrett classification. Endomicroscopic and histological findings were compared.

RESULTS

Forty-eight out of 50 screened patients underwent endomicroscopy. Visible lesions were observed in 3 patients. In a per-biopsy analysis, Barrett's-oesophagus-associated neoplasia could be predicted with an accuracy of 98.1%. The agreement between endomicroscopic and histological results was substantial (κ=0.76).

CONCLUSIONS

This study suggests that endomicroscopy can provide in vivo diagnosis of Barrett's oesophagus-associated neoplasia. Because it allows for the study of larger surface areas of the mucosa, endomicroscopy may lead to significant improvements in the in vivo screening and surveillance of Barrett's oesophagus.

Endoscopic management of Barrett's esophagus: advances in endoscopic techniques

Barrett's esophagus (BE) is a well-known premalignant condition that can be associated with the development of dysplasia and adenocarcinoma. In the past, esophagectomy was the standard treatment for patients with BE with high grade dysplasia (HGD) and early cancer (EC). However, esophagectomy is not necessarily the only treatment response to HGD and EC anymore. Over the past decade, a number of endoscopic therapies have been developed for management of BE. These include endoscopic mucosal resection, thermal ablation techniques that use laser irradiation, multipolar electrocoagulation, argon plasma coagulation, photodynamic therapy, and the recently developed cryotherapy and radiofrequency ablation.

[Barrett's esophagus. An update]

Barrett's esophagus (BE), a well-known complication of gastroesophageal reflux disease (GERD), constitutes a precancerous condition for adenocarcinoma of the distal esophagus. The so-called Barrett's carcinoma shows increasing incidences in countries of the western hemisphere; new data, however, indicate that the rise in incidence is not quite as dramatic as previously assumed. The definition of BE is currently changing: despite good reasons for a purely endoscopic definition of BE, goblet cells are still mandatory for this diagnosis in Germany and the USA. Dysplastic changes in the epithelium are the most important risk factor for the development of Barrett's adenocarcinoma and recently dysplasia was subclassified into a more frequent adenomatous (intestinal) and a non-adenomatous (gastric-foveolar) types. The gold standard for diagnosing dysplasia is still H&E staining. The histological diagnosis of dysplasia is still encumbered by a significant interobserver variability, especially regarding the differentiation between low grade dysplasia and inflammatory/reactive changes and the discrimination between high grade dysplasia and adenocarcinoma. Current data, however, show much higher interobserver agreement in endoscopic resection specimens than in biopsies. Nevertheless, the histological diagnosis of dysplasia should be corroborated by an external second opinion because of its clinical consequences. In endoscopic resections of early Barrett's adenocarcinoma, the pathological report has to include a risk stratification for the likelihood of lymphogenic metastases.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The minimal incubation period from the onset of Barrett's oesophagus to symptomatic adenocarcinoma

Background:

The interval between the onset of Barrett's oesophagus (BO) and oesophageal adenocarcinoma (OAC) can be termed the incubation period. However, the unrecorded onset of BO precludes its direct observation.

Methods:

Determining the range of intervals between BO diagnosis and OAC within the longest observational BO follow-up study. Exclusion criteria were presence of high-grade dysplasia (HGD) or OAC at baseline, death within <2 years of BO diagnosis, oesophagectomy without HGD/OAC and loss to follow-up. A total of 133 patients (M/F 73/60) were taken into account.

Results:

In 1967 person years of follow-up there were 13 cases of HGD/OAC, (0.66% p.a.; 95% CI 0.58–0.74), 96 patients died without HGD/OAC and 24 survived without HGD/OAC. The mean intervals between BO diagnosis and either HGD/OAC, death or end of follow-up were 10.8, 12.6 and 25.5 years, respectively, and the mean ages at endpoint were 72.5, 80.0 and 68.3 years, respectively. The survivors without HGD/OAC had a lower age at BO diagnosis (mean 42.8 vs 61.2 and 67.4 years, P<0.001). Baseline presence of low-grade dysplasia was associated with progression to HGD/OAC (log rank P<0.001).

Conclusion:

The Rotterdam BO follow-up cohort revealed a long incubation period between onset of BO and development of HGD/OAC, in patients without HGD/OAC at baseline as illustrated by 24 patients diagnosed with BO at a young age and followed for a mean period of 25.5 years. Their tumour-free survival established a minimum incubation period, suggesting a true incubation period of three decades or more.

Barrett's adenocarcinoma of the esophagus: better outcomes through new methods of diagnosis and treatment

BACKGROUND

Esophageal adenocarcinoma has attracted more attention among gastroenterologists recently because of its rapidly rising incidence in Western countries. Many new epidemiological findings have been published, and there have been numerous technical advances in diagnostic procedures and in multimodal treatment based on the staging of the disease.

METHODS

In this paper, we selectively review the literature on esophageal adenocarcinoma, also considering the evidence-based recommendations contained in the guidelines of the German Society for Digestive and Metabolic Diseases (Deutsche Gesellschaft für Verdauungs- und Stoffwechselkrankheiten, DGVS) as well as the latest data from our own research team.

RESULTS AND CONCLUSION

here have been major recent advances in the diagnosis and treatment of esophageal adenocarcinoma. New refinements in endoscopic techniques now make endoscopic treatment possible for early esophageal carcinoma. New surgical techniques and new strategies of neoadjuvant chemotherapy have lowered the morbidity and improved the outcome of patients with locally advanced disease. Molecular therapies, too, have shown promising initial results.

Barrett's esophagus: A historical perspective, an update on core practicalities and predictions on future evolutions of management

Interpretation of exploding knowledge about Barrett's esophagus is impaired by use of several conflicting definitions. Because any histological type of esophageal columnar metaplasia carries risk for esophageal adenocarcinoma, the diagnosis of Barrett's esophagus should no longer require demonstration of intestinal-type metaplasia. Endoscopic recognition and grading of Barrett's esophagus remains a significant source of ambiguity. Reflux disease is a key factor for development of Barrett's esophagus, but other factors must underlie its development, since it occurs in only a minority of reflux disease patients. Neither antireflux surgery nor proton pump inhibitor (PPI) therapy has major impacts on cancer risk. Within a year, a major trial should indicate whether low-dose aspirin usefully reduces cancer risk. The best referral centers have transformed the accuracy of screening and surveillance for early curable esophageal adenocarcinoma by use of enhanced and novel endoscopic imaging, visually-guided, rather than blind biopsies and by partnership with expert pathologists. General endoscopists now need to upgrade their skills and equipment so that they can rely mainly on visual targeting of biopsies on mucosal areas of concern in their surveillance practice. General pathologists need to greatly improve their interpretation of biopsies. Endoscopic therapy now achieves very high rates of cure of high-grade dysplasia and esophageal adenocarcinoma with minimal morbidity and risk. Such results will only be achieved by skilled interventional endoscopists. Esophagectomy should now be mainly restricted to patients whose cancer has extended into and beyond the submucosa. Weighing risks and benefits in the management of Barrett's esophagus is difficult, as is the process of adequately informing patients about their specific cancer risk.

Effect of medical and surgical treatment of Barrett’s metaplasia

Barrett’s esophagus (BE) is a change in the esophageal mucosa as a result of long-standing gastroesophageal reflux disease. The importance of BE is that it is the main risk factor for the development of esophageal adenocarcinoma, whose incidence is currently growing faster than any other cancer in the Western world. The aim of this review was to compare the common treatment modalities of BE, with the focus on proton pump inhibitors and operative fundoplication. We performed a literature search on medical and surgical treatment of BE to determine eligible studies for this review. Studies on medical and surgical treatment of BE are discussed with regard to treatment effect on progression and regression of disease. Although there is some evidence for control of reflux with either medical or surgical therapy, there is no definitive evidence that either treatment modality decreases the risk of progression to dysplasia or cancer. Even though there is a trend toward antireflux surgery being superior, there are no definitive studies to prove this.

Cost-effectiveness of treatment and endoscopic surveillance of precancerous lesions to prevent gastric cancer

BACKGROUND

Although surveillance for Barrett esophagus and other gastrointestinal precancerous conditions is recommended, no analogous guidelines exist for gastric lesions. The objective of this study was to estimate the clinical benefits and cost-effectiveness of treatment and endoscopic surveillance to prevent gastric cancer.

METHODS

The authors developed a state-transition decision model for a cohort of US men with a recent incidental diagnosis of gastric precancerous lesions (dysplasia, intestinal metaplasia, or atrophy). Strategies included 1) no surveillance or treatment and 2) referral for surveillance and treatment, and varied by surveillance frequency (none, every 10 years, every 5 years, or every year) and treatment modality for dysplastic and cancerous lesions (surgery or endoscopic mucosal resection [EMR]). The term "post-treatment surveillance" was restricted to surveillance of individuals after treatment. Data were based on published literature and databases. Outcomes included lifetime gastric cancer risk, quality-adjusted life expectancy, lifetime costs, and incremental cost-effectiveness ratios.

RESULTS

For a cohort of men with dysplasia aged 50 years, the lifetime gastric cancer risk was 5.9%. EMR with annual surveillance reduced the lifetime cancer risk by 90% and cost $39,800 per quality-adjusted life year (QALY). Addition of post-treatment surveillance every 10 years provided little incremental benefit ( approximately 5%) but cost >$1 million per QALY. Results were most sensitive to surgical risks and the proportion of lesions completely removed with EMR. For intestinal metaplasia, surveillance every 10 years reduced lifetime cancer risk by 61% and cost $544,500 per QALY.

CONCLUSIONS

EMR with surveillance every 1 to 5 years for gastric dysplasia was promising for secondary cancer prevention and had a cost-effectiveness ratio that would be considered attractive in the United States. Endoscopic surveillance of less advanced lesions did not appear to be cost-effective, except possibly for immigrants from high-risk countries.

Review: treatment of gastroesophageal reflux disease in the elderly

The prevalence of gastroesophageal reflux disease (GERD) increases with age; older patients are more likely to develop severe disease. Common symptoms of GERD in the elderly include dysphagia, vomiting, and respiratory problems. Older patients are more likely to require aggressive therapy, and usually their management is compounded by the presence of comorbidities and consumption of various medications. Proton pump inhibitors are the mainstay of GERD treatment in the elderly because of their profound and consistent acid suppressive effect. Overall, proton pump inhibitors seem to be safe for both short- and long-term therapy in elderly patients with GERD. Antireflux surgery may be safe and effective in a subset of elderly patients with GERD.

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

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