Histopathology of Barrett's esophagus after ablation and endoscopic mucosal resection therapy

Inflammatory bowel disease- and Barrett's esophagus-associated neoplasia: the old, the new, and the persistent struggles

Early diagnosis of and adequate therapy for premalignant lesions in patients with inflammatory bowel disease (IBD) and Barrett's esophagus (BE) has been shown to decrease mortality. Endoscopic examination with histologic evaluation of random and targeted biopsies remains the gold standard for early detection and adequate treatment of neoplasia in both these diseases. Although eventual patient management (including surveillance and treatment) depends upon a precise histologic assessment of the initial biopsy, accurately diagnosing and grading IBD- and BE-associated dysplasia is still considered challenging by many general as well as subspecialized pathologists. Additionally, there are continuing updates in the literature regarding the diagnosis, surveillance, and treatment of these disease entities. This comprehensive review discusses the cancer risk, detailed histopathological features, diagnostic challenges, and updates as well as the latest surveillance and treatment recommendations in IBD- and BE-associated dysplasia.

Care of the Postablation Patient: Surveillance, Acid Suppression, and Treatment of Recurrence

Endoscopic eradication therapy is effective and durable for the treatment of Barrett's esophagus (BE), with low rates of recurrence of dysplasia but significant rates of recurrence of intestinal metaplasia. Identified risk factors for recurrence include age and length of BE before treatment and may also include presence of a large hiatal hernia, higher grade of dysplasia before treatment, and history of smoking. Current guidelines for surveillance following ablation are limited, with recommendations based on low-quality evidence and expert opinion. New modalities including optical coherence tomography and wide-area tissue sampling with computer-assisted analysis show promise as adjunctive surveillance modalities.

Diagnostic approaches and treatment of eosinophilic esophagitis. A review article

Eosinophilic Esophagitis (EoE) is a condition that involves eosinophilic influx into the esophageal epithelium. It affects both children and adults; Adults present with dysphagia whereas children with vague abdominal complaints. The clinical symptoms as well as pathologic features of EoE and gastro esophageal reflux disease (GERD) are similar. Since eosinophilia in the esophagus is a non-specific finding, the clinical presentation in conjunction with endoscopic findings and pathology, is crucial in determining a differential diagnosis. Infections such as parasites, allergic phenomenon, Crohn's disease, malignancies, medication, and chemotherapy are all associated with eosinophilia.

A primary endoscopic difference to note between EoE and GERD is that EoE often involves long segments of the esophagus, could be patchy or focal and frequently involves the proximal esophagus. GERD, however, typically involves the distal much more frequently than the proximal esophagus. Because of the similarity between them, GERD should be excluded by using high dose proton pump inhibitor (PPI) treatment or through evidence of a normal pH by esophageal testing, prior to treatment with an elimination diet or steroids. Until further research establishes different diagnostic tests and criteria, clinical and pathological response to therapy is considered to be the absolute confirmation of this diagnosis. The following is a more detailed discussion of this entity.

•

EoE is an eosinophilic influx into the esophagus epithelium.

•

It is an allergic reaction of esophagus to food particles and allergens.

•

Adults present with dysphagia and reflux-like symptoms whereas children with vague abdominal complaints.

•

Clinical presentation, endoscopic findings and pathology determine the definitive diagnosis.

•

Treatment starts with an elimination diet and followed by orally swallowed inhaled steroids.

Handling and Pathology Reporting of Gastrointestinal Endoscopic Mucosal Resection

Endoscopic mucosal resection (EMR) is a non-invasive alternative to surgery that is now frequently used for resection of early lesions in both upper and lower parts of the gastrointestinal (GI) tract. One of the main advantages of these techniques is providing tissue for histopathological examination. Pathological examination of endoscopically resected specimens of GI tract is a crucial component of these procedures and is useful for prediction of both the risk of metastasis and lymph node involvement.

As the first step, it is very important for the pathologist to handle the EMR gross specimen in the correct way: it should be oriented, and then the margins should be labeled and inked accurately before fixation.

In the second step, the EMR pathological report should include all the detailed information about the diagnosis, grading, depth of invasion (mucosa only or submucosal involvement), status of the margins, and the presence or absence of lymphovascular invasion.

The current literature (PubMed and Google Scholar) was searched for the words "endoscopic mucosal resection" to find all relevant publications about this technique with emphasis on the pathologist responsibilities.

Post-ablation lymphocytic esophagitis in Barrett esophagus with high grade dysplasia or intramucosal carcinoma

In patients who have undergone ablation therapy for treatment of Barrett's esophagus with dysplasia, histologic features of eosinophilic esophagitis, but not lymphocytic esophagitis, have been described. We evaluated for histologic evidence of eosinophilic esophagitis and lymphocytic esophagitis and correlated with endoscopic findings in this population. A single-institution Barrett's esophagus registry was searched for patients who had received radiofrequency ablation, cryotherapy, or both for treatment of Barrett's esophagus with dysplasia. Clinical and endoscopic data were collected and biopsies were reviewed for inflammation and reactive changes at three time points: pre-intervention, first surveillance after ablation therapy, and most recent surveillance. Of the 173 patients initially identified, 102 met the inclusion criteria. Intraepithelial eosinophils were increased at first surveillance (60%, P=0.096) and last surveillance (69%, P=0.048) compared with pre-intervention (50%), although histologic evidence of post-ablation eosinophilic esophagitis was not significant. Prevalence of lymphocytic esophagitis was significantly higher at first surveillance (17%, P=0.02) and at last surveillance (43%, P<0.001), compared with pre-intervention (7%). Smoking, hyperlipidemia, and cryotherapy were identified as independent risk factors for developing histologic lymphocytic esophagitis. This is the first report that histologic evidence of lymphocytic esophagitis increased over time in patients undergoing ablation for Barrett's esophagus with dysplasia. Though the pathophysiology of lymphocytic esophagitis remains unknown, patients in our study with a history of smoking, hyperlipidemia, or cryotherapy were more likely to develop post-ablation lymphocytic esophagitis.

Post-ablation surveillance in Barrett's esophagus: A review of the literature

Barrett’s esophagus (BE) is a pre-malignant condition affecting up to 15% of patients with gastroesophageal reflux disease. Neoplastic Barrett’s mucosa is defined as harboring high grade dysplasia or intra-mucosal cancer, and carries a high risk of progression to esophageal adenocarcinoma. The rising incidence of Barrett’s lesions along with the high morbidity of surgical approaches has led to the development of numerous validated endoscopic techniques capable of eradicating neoplastic mucosa in a minimally invasive manner. While there has been widespread adoption of these techniques, less is known about optimal surveillance intervals in the post-therapy period. This is due in part to limitations in current surveillance methods, questions about durability of treatment response and the risk of subendothelial progression. As we are now able to achieve organ sparing eradication of superficial neoplasia in BE, we need to also then focus our attention on how best to manage these patients after eradication is achieved. Implementing optimal surveillance practices requires additional understanding of the biology of the disease, appreciation of the limits of current tools and treatments, and exploration of the role of adjunctive technologies. The aim of this article is to provide a comprehensive review of current literature surrounding post-ablation surveillance in neoplastic BE.

Label-free multi-photon imaging of dysplasia in Barrett's esophagus

Barrett's esophagus (BE) is a metaplastic disorder where dysplastic and early cancerous changes are invisible to the naked eye and where the practice of blind biopsy is hampered by large sampling errors. Multi-photon microscopy (MPM) has emerged as an alternative solution for fast and label-free diagnostic capability for identifying the histological features with sub-micron accuracy. We developed a compact, inexpensive MPM system by using a handheld mode-locked fiber laser operating at 1560nm to study mucosal biopsies of BE. The combination of back-scattered THG, back-reflected forward THG and SHG signals generate images of cell nuclei and collagen, leading to label-free diagnosis in Barrett's.

Endoscopic Optical Coherence Tomography for Clinical Gastroenterology

Optical coherence tomography (OCT) is a real-time optical imaging technique that is similar in principle to ultrasonography, but employs light instead of sound waves and allows depth-resolved images with near-microscopic resolution. Endoscopic OCT allows the evaluation of broad-field and subsurface areas and can be used ancillary to standard endoscopy, narrow band imaging, chromoendoscopy, magnification endoscopy, and confocal endomicroscopy. This review article will provide an overview of the clinical utility of endoscopic OCT in the gastrointestinal tract and of recent achievements using state-of-the-art endoscopic 3D-OCT imaging systems.

Nrf2 deficiency impairs the barrier function of mouse oesophageal epithelium

OBJECTIVE

As a major cellular defence mechanism, the Nrf2/Keap1 pathway regulates expression of genes involved in detoxification and stress response. Here we hypothesise that Nrf2 is involved in oesophageal barrier function and plays a protective role against gastro-oesophageal reflux disease (GERD).

DESIGN

Human oesophageal biopsy samples, mouse surgical models and Nrf2(-/-) mice were used to assess the role of the Nrf2/Keap1 pathway in oesophageal barrier function. Trans-epithelial electrical resistance (TEER) was measured with mini-Ussing chambers. HE staining and transmission electron microscopy were used to examine tissue morphology, while gene microarray, immunohistochemistry, western blotting and chromatin immunoprecipitation (ChIP) analysis were used to assess gene expression.

RESULTS

Nrf2 was expressed in normal oesophageal epithelium and activated in GERD of both humans and mice. Nrf2 deficiency and gastro-oesophageal reflux in mice, alone or in combination, reduced TEER and increased intercellular space in oesophageal epithelium. Nrf2 target genes and gene sets associated with oxidoreductase activity, mitochondrial biogenesis and energy production were downregulated in the oesophageal epithelium of Nrf2(-/-) mice. Consistent with the antioxidative function of Nrf2, a DNA oxidative damage marker (8OHdG) dramatically increased in oesophageal epithelial cells of Nrf2(-/-) mice compared with those of wild-type mice. Interestingly, ATP biogenesis, Cox IV (a mitochondrial protein) and Claudin 4 (Cldn4) expression were downregulated in the oesophageal epithelium of Nrf2(-/-) mice, suggesting that energy-dependent tight junction integrity was subject to Nrf2 regulation. ChIP analysis confirmed the binding of Nrf2 to Cldn4 promoter.

CONCLUSIONS

Nrf2 deficiency impairs oesophageal barrier function through disrupting energy-dependent tight junction.

How good is the neosquamous epithelium?

BACKGROUND/AIMS

Endoscopic radiofrequency ablation of dysplastic Barrett's esophagus (BE) combined with proton pump inhibitor therapy is commonly utilized for preventing progression of dysplastic BE to esophageal adenocarcinoma. Fundamental to the success of this and all ablative approaches is the healing of the ablated areas of BE with a stratified squamous epithelium referred to as 'neosquamous epithelium' (NSE). Although NSE appears 'normal' endoscopically, the reemergence of BE over time in the previously ablated segments raises the question of the health and integrity of NSE.

METHODS

The health of NSE was recently investigated in endoscopic biopsies in vitro in a group of patients after ablation while on proton pump inhibitors. Biopsies of NSE were compared to upper squamous epithelium (USE) from the same patients morphologically (light microscopy) and with respect to barrier function by measuring electrical resistance and fluorescein flux in mini-Ussing chambers.

RESULTS

Compared to USE, NSE exhibited dilated intercellular spaces and inflammation and defective barrier function by low electrical resistance and high fluorescein flux. Moreover, NSE exhibited downregulation of claudin-4, a highly expressed protein in squamous tight junctions.

CONCLUSION

NSE has defective barrier function in part due to downregulation of claudin-4. Since downregulation of claudin-4 increases paracellular permeability to cations, e.g. hydrogen ions, NSE is more vulnerable to attack and damage by acidic and weakly acidic refluxates--a phenomenon that may contribute in part to the reemergence of BE.

Barrett esophagus: diagnostic challenges

The incidence of esophageal adenocarcinoma and associated mortality has risen dramatically over the past several decades, and, thus, it is increasingly important to understand its pathogenesis and risk factors. Barrett esophagus is the established precursor to esophageal adenocarcinoma that progresses through a metaplasia-dysplasia-carcinoma sequence. Its risk of transforming to carcinoma is not as high as previously reported and there appears to be a biological heterogeneity among patients with this disease. The overall prevalence of Barrett esophagus in the United States ranges from 1% to 25% and is closer to 5% in patients with gastroesophageal reflux disease. Because of the frequency of Barrett esophagus and associated implications, it is important for the practicing pathologist to have a thorough understanding of this disease and its diagnostic pitfalls. In this review, we will discuss issues associated with the diagnosis of Barrett esophagus, including the definition of Barrett esophagus and its distinction from carditis with intestinal metaplasia. We will also discuss challenges in the grading of dysplasia and new variants of dysplasia, including crypt dysplasia and foveolar-type dysplasia. Finally, we will touch upon the evaluation of dysplasia in endoscopic mucosal resection specimens.

Management controversies in Barrett's oesophagus

The management of Barrett's oesophagus and associated neoplasia has evolved considerably in recent years. Modern endoscopic strategies including endoscopic resection and mucosal ablation can eradicate dysplastic Barrett's and prevent progression to invasive oesophageal cancer. However, several aspects of Barrett's management remain controversial including the stage in the disease process at which to intervene, and the choice of endoscopic or surgical therapy. A review of articles pertaining to the management of Barrett's oesophagus with or without associated neoplasia, was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Medline, Embase and Cochrane databases were searched to identify literature relevant to eight pre-defined areas of clinical controversy. The following search terms were used: Barrett's oesophagus; dysplasia; intramucosal carcinoma; endotherapy; endoscopic resection; ablation; oesophagectomy. A significant body of evidence exists to support early endoscopic therapy for high-grade dysplasia (HGD). Although not supported by randomised controlled trial evidence, endoscopic therapy is now favoured ahead of oesophagectomy for most patients with HGD. Focal intramucosal (T1a) carcinomas can be managed effectively using endoscopic and surgical therapy, however surgery should be considered the first line therapy where there is submucosal invasion (T1b). Treatment of low grade dysplasia is not supported at present due to widespread over-reporting of the disease. The role of surveillance endoscopy in non-dysplastic Barrett's remains controversial.

British Society of Gastroenterology guidelines on the diagnosis and management of Barrett's oesophagus

These guidelines provide a practical and evidence-based resource for the management of patients with Barrett's oesophagus and related early neoplasia. The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument was followed to provide a methodological strategy for the guideline development. A systematic review of the literature was performed for English language articles published up until December 2012 in order to address controversial issues in Barrett's oesophagus including definition, screening and diagnosis, surveillance, pathological grading for dysplasia, management of dysplasia, and early cancer including training requirements. The rigour and quality of the studies was evaluated using the SIGN checklist system. Recommendations on each topic were scored by each author using a five-tier system (A+, strong agreement, to D+, strongly disagree). Statements that failed to reach substantial agreement among authors, defined as >80% agreement (A or A+), were revisited and modified until substantial agreement (>80%) was reached. In formulating these guidelines, we took into consideration benefits and risks for the population and national health system, as well as patient perspectives. For the first time, we have suggested stratification of patients according to their estimated cancer risk based on clinical and histopathological criteria. In order to improve communication between clinicians, we recommend the use of minimum datasets for reporting endoscopic and pathological findings. We advocate endoscopic therapy for high-grade dysplasia and early cancer, which should be performed in high-volume centres. We hope that these guidelines will standardise and improve management for patients with Barrett's oesophagus and related neoplasia.

Barrett Esophagus: Evolving Concepts in Diagnosis and Neoplastic Progression

Surgical pathologists need to answer 2 questions when evaluating biopsies from the distal esophagus or gastroesophageal junction in patients with a history of gastroesophageal reflux disease: Are the findings consistent with Barrett esophagus? and Is there any evidence of dysplasia? Pathologists should be well informed about the controversy around the definition of Barrett esophagus and the common pitfalls that lead to a false-positive diagnosis of Barrett esophagus or Barrett esophagus-associated dysplasia. A concise description of distinct morphologic types of dysplasia in Barrett esophagus and a summary of recent data on the natural history of BE are provided in this review.

Esophageal squamous cell carcinoma arising after endoscopic ablation therapy of Barrett's esophagus with high-grade dysplasia. Report of a case

Patients with Barrett's esophagus are at risk for dysplasia and esophageal adenocarcinoma. Although surgery was the mainstay treatment for Barrett's dysplasia and cancer, patients with high-grade dysplasia and early cancers now have several nonsurgical treatment options. Most of the endoscopic therapies are relatively safe but do carry a risk for complications. Treatment failure with progression of the disease is the most severe complication, especially among patients with low surgical risk. Cryoablation has been used with promising results in both high-grade dysplasia and early esophageal cancer. A patient with a well-documented history of Barrett's esophagus with high-grade dysplasia that underwent multiple sessions of photodynamic therapy and salvage cryoablation for residual high-grade dysplasia was presented. The patient was diagnosed with squamous cell carcinoma of the distal esophagus approximately 1 year after cryoablation. This is the first complete report of squamous cell carcinoma occurring after endoscopic ablation for Barrett's neoplasia. Careful follow up is necessary in any endoscopic ablation program due to the risk of recurrent neoplasia.

Structural markers observed with endoscopic 3-dimensional optical coherence tomography correlating with Barrett's esophagus radiofrequency ablation treatment response (with videos)

BACKGROUND

Radiofrequency ablation (RFA) is effective for treating Barrett's esophagus (BE) but often involves multiple endoscopy sessions over several months to achieve complete response.

OBJECTIVE

Identify structural markers that correlate with treatment response by using 3-dimensional (3-D) optical coherence tomography (OCT; 3-D OCT).

DESIGN

Cross-sectional.

SETTING

Single teaching hospital.

PATIENTS

Thirty-three patients, 32 male and 1 female, with short-segment (<3 cm) BE undergoing RFA treatment.

INTERVENTION

Patients were treated with focal RFA, and 3-D OCT was performed at the gastroesophageal junction before and immediately after the RFA treatment. Patients were re-examined with standard endoscopy 6 to 8 weeks later and had biopsies to rule out BE if not visibly evident.

MAIN OUTCOME MEASUREMENTS

The thickness of BE epithelium before RFA and the presence of residual gland-like structures immediately after RFA were determined by using 3-D OCT. The presence of BE at follow-up was assessed endoscopically.

RESULTS

BE mucosa was significantly thinner in patients who achieved complete eradication of intestinal metaplasia than in patients who did not achieve complete eradication of intestinal metaplasia at follow-up (257 ± 60 μm vs 403 ± 86 μm; P < .0001). A threshold thickness of 333 μm derived from receiver operating characteristic curves corresponded to a 92.3% sensitivity, 85% specificity, and 87.9% accuracy in predicting the presence of BE at follow-up. The presence of OCT-visible glands immediately after RFA also correlated with the presence of residual BE at follow-up (83.3% sensitivity, 95% specificity, 90.6% accuracy).

LIMITATIONS

Single center, cross-sectional study in which only patients with short-segment BE were examined.

CONCLUSION

Three-dimensional OCT assessment of BE thickness and residual glands during RFA sessions correlated with treatment response. Three-dimensional OCT may predict responses to RFA or aid in making real-time RFA retreatment decisions in the future.

Ablation of Barrett's oesophagus: towards improved outcomes for oesophageal cancer?

Barrett's oesophagus is the major risk factor for the development of oesophageal adenocarcinoma. The management of Barrett's oesophagus entails treating reflux symptoms with acid-suppressing medication or surgery (fundoplication). However, neither form of anti-reflux therapy produces predictable regression, or prevents cancer development. Patients with Barrett's oesophagus usually undergo endoscopic surveillance, which aims to identify dysplastic changes or cancer at its earliest stage, when treatment outcomes should be better. Alternative endoscopic interventions are now available and are suggested for the treatment of early cancer and prevention of progression of Barrett's oesophagus to cancer. Such treatments could minimize the risks associated with oesophagectomy. The current status of these interventions is reviewed. Various endoscopic interventions have been described, but with long-term outcomes uncertain, they remain somewhat controversial. Radiofrequency ablation of dysplastic Barrett's oesophagus might reduce the risk of cancer progression, although cancer development has been reported after this treatment. Endoscopic mucosal resection (EMR) allows a 1.5-2 cm diameter piece of oesophageal mucosa to be removed. This provides better pathology for diagnosis and staging, and if the lesion is confined to the mucosa and fully excised, EMR can be curative. The combination of EMR and radiofrequency ablation has been used for multifocal lesions, but long-term outcomes are unknown. The new endoscopic interventions for Barrett's oesophagus and early oesophageal cancer have the potential to improve clinical outcomes, although evidence that confirms superiority over oesphagectomy is limited. Longer-term outcome data and data from larger cohorts are required to confirm the appropriateness of these procedures.

Comparison of Tissue Architectural Changes between Radiofrequency Ablation and Cryospray Ablation in Barrett's Esophagus Using Endoscopic Three-Dimensional Optical Coherence Tomography

Two main nonsurgical endoscopic approaches for ablating dysplastic and early cancer lesions in the esophagus have gained popularity, namely, radiofrequency ablation (RFA) and cryospray ablation (CSA). We report a uniquely suited endoscopic and near-microscopic imaging modality, three-dimensional (3D) optical coherence tomography (OCT), to assess and compare the esophagus immediately after RFA and CSA. The maximum depths of architectural changes were measured and compared between the two treatment groups. RFA was observed to induce 230~260 μm depth of architectural changes after each set of ablations over a particular region, while CSA was observed to induce edema-like spongiform changes to ~640 μm depth within the ablated field. The ability to obtain micron-scale depth-resolved images of tissue structural changes following different ablation therapies makes 3D-OCT an ideal tool to assess treatment efficacy. Such information could be potentially used to provide real-time feedback for treatment dosing and to identify regions that need further retreatment.

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

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

Radiofrequency ablation for dysplasia in Barrett's esophagus restores β-catenin activation within esophageal progenitor cells

BACKGROUND AND AIMS

Endoscopic therapies for Barrett's esophagus (BE) associated dysplasia, particularly radiofrequency ablation (RFA), are popular alternatives to surgery. The effect of such therapies on dysplastic stem/progenitor cells (SPC) is unknown. Recent studies suggest that AKT phosphorylation of β-Catenin occurs in SPCs and may be a marker of activated SPCs. We evaluate the effect of RFA in restoring AKT-mediated β-Catenin signaling in regenerative epithelium.

METHODS

Biopsies were taken from squamous, non-dysplastic BE, dysplastic BE and esophageal adenocarcinoma (EAC). Also, post-RFA, biopsies of endoscopically normal appearing neosquamous epithelium were taken at 3, 6, and 12 months after successful RFA. Immunohistochemistry and Western blot analysis was performed for Pβ-Catenin(552) (Akt-mediated phosphorylation of β-Catenin), Ki-67 and p53.

RESULTS

There was no difference in Pβ-Catenin552 in squamous, GERD, small bowel and non-dysplastic BE. There was a fivefold increase in Pβ-Catenin(552) in dysplasia and EAC compared to non-dysplastic BE (P < 0.05). Also, there was a persistent threefold increase in Pβ-Catenin(552) in neosquamous epithelium 3 months after RFA compared to native squamous epithelium (P < 0.05) that correlated with increased Ki-67. Six months after RFA, Pβ-Catenin(552) and Ki-67 are similar to native squamous epithelium.

CONCLUSIONS

Enhanced AKT-mediated β-Catenin activation is seen in BE-associated carcinogenesis. Three months after RFA, squamous epithelial growth from SPC populations exhibited increased levels of Pβ-Catenin(552). This epithelial response becomes quiescent at 6 months after RFA. These data suggest that elevated Pβ-Catenin(552) after RFA denotes a repair response in the neosquamous epithelium 3 months post-RFA.

Endoscopic therapies for the prevention and treatment of early esophageal neoplasia

Esophageal cancers have traditionally been diagnosed late and prognosis has been dire. For many years the only real treatment option was esophagectomy with substantial morbidity and mortality. This situation has now changed dramatically. Improvements have been achieved in surgical outcomes and there is an array of new effective treatment options now available, particularly for the increasing proportion diagnosed with early-stage disease. Minimally invasive endoscopic therapies can now prevent, cure or palliate esophageal cancers. This article aims to investigate the role and evidence base for these new therapeutic options.

Efficacy and safety of EMR to completely remove Barrett's esophagus: experience in 41 patients

BACKGROUND

EMR is typically used to remove focal abnormalities of the esophageal mucosa. However, larger areas of Barrett's esophagus (BE) can be resected through side-by-side resections.

OBJECTIVE

To assess the efficacy and safety of EMR to completely remove BE.

DESIGN

Retrospective, single-center study.

SETTING

University of Iowa Hospitals and Clinics.

PATIENTS

Between January 2006 and December 2010, 46 patients underwent EMR for complete removal of BE. Three were lost to follow-up, one died of unrelated causes before completion, and one was still undergoing EMR treatment at the conclusion of the study. The remaining 41 patients were included for analysis. The worst histologic grade was low-grade dysplasia in 4 patients, high-grade dysplasia without cancer in 26 patients, and high-grade dysplasia with superficial adenocarcinoma in 11 patients. BE was circumferential in 65.9% of cases, and the mean (± SD) length was 3.3 ± 2.3 cm.

INTERVENTION

EMR was performed by using a cap (n = 4), a multiband ligator device (n = 31), or both (n = 6), with a mean (± SD) of 2.4 ± 1.2 sessions per patient.

MAIN OUTCOME MEASUREMENTS

Remission rates and complications.

RESULTS

Remission of high-grade dysplasia and cancer, all dysplasia, and all BE was achieved in 94.6%, 85.4%, and 78.0%, respectively. Complications included minor bleeding (31.7%), perforations (4.9%), and strictures (43.9%). All complications were managed conservatively.

LIMITATIONS

Retrospective design.

CONCLUSION

Complete removal of BE with EMR is effective but associated with a high complication rate, which is mainly related to stricture formation. This needs to be considered when choosing between available treatment modalities.

Comparison of COX-2, Ki-67, and BCL-2 expression in normal esophageal mucosa, Barrett's esophagus, dysplasia, and adenocarcinoma with postablation mucosa and implications for ablative therapies

BACKGROUND

The neosquamous mucosa that replaces ablated esophageal endothelium after endoscopic mucosal ablation for Barrett's metaplasia or high-grade dysplasia (HGD) may retain buried glandular tissue. This study aimed to assess the neoplastic potential, cellular proliferation, and resistance to apoptosis of this buried glandular tissue by measuring COX-2, Ki-67, and BCL-2 expression in these tissues.

METHODS

A prospectively collected database was sourced for esophageal biopsy specimens with normal histologic appearance, Barrett's metaplasia, HGD, adenocarcinoma, and postablation mucosa comprising ablated Barrett's and ablated HGD. Quantitative analysis of cellular markers was achieved immunohistochemically using monoclonal antibodies for the COX-2 enzyme (suggesting increased neoplastic potential), Ki-67 antigen (suggesting cellular proliferation), and BCL-2 oncoprotein (suggesting oncogenic resistance to apoptosis). Grading was performed by independent, blinded observers, and the pre- and postablation cellular disparities were subsequently noted.

RESULTS

The buried glandular elements of postablation mucosa demonstrated universally greater COX-2, Ki-67, and BCL-2 expression than normal esophagus. Barrett's esophagus and adenocarcinoma expressed significantly greater COX-2 and Ki-67 at the deep glandular level than postablation mucosa. HGD demonstrated greater Ki-67 expression than the postablation tissue but only within the superficial glands. Overall, the expression of COX-2 correlated significantly with Ki-67 expression in deep glandular tissue.

CONCLUSIONS

Ablation of pathologic mucosa in Barrett's esophagus and HGD reduces the expression of some markers of neoplastic behavior. However, the buried glandular tissue of the postablation mucosa still exhibits a higher expression than normal esophageal epithelium. This has potential implications for the follow-up treatment of these patients because it is unclear whether the true risk of neoplastic progression is adequately reduced. A more comprehensive study is required to address this issue.

Staging of early adenocarcinoma in Barrett's esophagus

The main goal in the staging of patients with early neoplasia arising in the context of Barrett's esophagus (BE) is to identify individuals who are eligible for endoscopic therapy and differentiate them from those who require surgical management. To make the proper patient selection a combined staging strategy consisting of endoscopy evaluation, endoscopic ultrasonography, and endoscopic mucosal resection is necessary. In this article, the authors summarize the evidence behind each different staging modality in the setting of early BE adenocarcinoma and propose a staging approach that helps to select patients who are suitable for endoscopic therapy.

Does ablative therapy for Barrett esophagus affect the depth of subsequent esophageal biopsy as compared with controls?

BACKGROUND

Photodynamic therapy (PDT) and radiofrequency ablation (RFA) are associated with high rates of complete eradication of Barrett esophagus (BE). However, if ablation were to induce fibrosis in the regenerated squamous epithelium, then postablation biopsies may not penetrate deeply enough to detect subsquamous intestinal metaplasia (SSIM) and, therefore, complete response rates could be over-estimated.

GOALS

To assess the depth of esophageal biopsies from the squamous epithelium of ablation-naive controls and from the neosquamous epithelium of post-PDT and post-RFA patients to determine if prior ablation results in a reduced proportion of biopsies containing lamina propria (LP) as compared with controls.

STUDY

Review of archived esophageal specimens from a prospective multicenter cohort study (post-RFA) and 2 retrospective consecutive case series (ablation-naive controls, post-PDT).

SETTING

Eight US centers and 1 US gastrointestinal pathology laboratory.

PATIENTS

Ablation-naive controls with GERD, dyspepsia, and/or BE. Post-PDT and post-RFA BE patients with biopsies more than 6 months after achieving complete eradication of BE.

INTERVENTIONS

Review of endoscopic biopsies from ablation-naive controls, post-PDT patients, and post-RFA patients.

MAIN OUTCOME MEASUREMENTS

One GI pathology lab processed all tissue and slides. One expert GI pathologist, blinded to cohort, graded the depth of each esophageal specimen as: partial epithelium, full epithelium, LP, muscularis mucosae, or submucosa. Each specimen was also evaluated for SSIM.

RESULTS

There were 82 patients [ablation-naive (12), post-PDT (10), post-RFA (60)] with 899 biopsy specimens. The proportion of specimens containing "LP or deeper" was similar between groups: ablation-naive (88%), post-PDT (88%), post-RFA (91%) (P>0.05). No SSIM was detected in any group.

CONCLUSIONS

There is no difference in esophageal biopsy depth between ablation-naive squamous epithelium and post-PDT/post-RFA neo-squamous epithelium, thus refuting the concern of ablation-induced mucosal resistance to procurement of adequate biopsy specimens. Most biopsies (88% to 91%) from both ablation cohorts were deep enough to detect SSIM, in that they included "LP or deeper."

Endoscopic mucosal resection in the management of esophageal neoplasia: current status and future directions

Endoscopic mucosal resection has expanded the role of the gastroenterologist in the management of esophageal neoplasia from screening and diagnosis to staging and endoscopic treatment. Its rise to prominence is a reflection of the long-identified need to obtain histologic information regarding depth of invasion and neoplastic margins during therapy that previously could not be achieved with ablative techniques. The resultant improvement in diagnosis and staging has allowed for better selection of patients for endoscopic therapy who may be spared invasive surgery. The clinical indications, endoscopic techniques, outcomes, and complications in the management of esophageal neoplasia are reviewed. Training requirements to achieve proficiency in endoscopic mucosal resection as well as potential quality measures to assess competence also are proposed in this review.

Biopsy depth after radiofrequency ablation of dysplastic Barrett's esophagus

BACKGROUND

After endoscopic radiofrequency ablation (RFA) of dysplastic Barrett's esophagus (BE), endoscopic biopsy samples are obtained to assess response to therapy. Whether these biopsies are of adequate depth to assess efficacy is unknown.

OBJECTIVE

To compare the depth of endoscopic biopsy samples after RFA with those of untreated controls and to determine the prevalence of subepithelial structures in endoscopic biopsy fragments.

DESIGN

Secondary analysis of the AIM Dysplasia Trial, a multicenter, randomized, sham-controlled study.

SETTING

Nineteen treatment centers.

PATIENTS

Subjects with dysplastic BE, either status post RFA or ablation naïve (sham).

MAIN OUTCOME MEASUREMENTS

The proportion of biopsy samples demonstrating subepithelial structures, stratified by tissue type (columnar vs squamous) in sham- and RFA-treated subjects.

RESULTS

A total of 5648 biopsy fragments were analyzed from 113 subjects (78 RFA, 35 sham; mean 50.0 fragments per subject). Most fragments (4653, 82.4%) contained subepithelium. Squamous biopsy samples from RFA and sham subjects demonstrated subepithelium at similar rates (78.4% vs 79.1%, respectively, P = not significant [NS]). Columnar biopsy samples from RFA and sham subjects also included subepithelium at similar rates (99.0% vs 98.8%, respectively, P = NS). Regardless of treatment assignment, more columnar than squamous biopsy samples demonstrated subepithelium (98.8% vs 78.5%, P < .001).

LIMITATIONS

Biopsy samples were not individually mounted.

CONCLUSIONS

In both squamous and columnar tissue, endoscopic biopsy samples after RFA were as likely to demonstrate subepithelium as untreated controls. Almost 80% of all biopsy samples were adequate to evaluate for subsquamous intestinal metaplasia. The primary determinant of biopsy depth is the type of epithelium that underwent biopsy, with squamous less likely to yield subepithelium than columnar. Biopsy samples after RFA appear to be of adequate depth to assess response to therapy. (Clinical trial registration number NCT00282672.).

The case for endoscopic treatment of non-dysplastic and low-grade dysplastic Barrett's esophagus

Non-dysplastic mucosa (ND-) in Barrett's esophagus (BE) shows clonal molecular aberrations, loss of cell cycle control, and other features of "neoplasia." These changes occur prior to morphologic expression of neoplasia (dysplasia). Morphologic evaluation of dysplasia is fraught with error, and, as a result, often leads to false-negative and false-positive diagnoses. Early "crypt dysplasia" is difficult to detect, and is often missed in routine biopsy specimens. Some studies show substantial progression rates of low-grade dysplasia (LGD), and crypt dysplasia, to esophageal adenocarcinoma (EAC). Dysplasia, even when fully developed, may, in certain circumstances, be difficult to differentiate from non-dysplastic (regenerating) BE. Radiofrequency ablation (RFA) is a safe and effective method for removing mucosa at risk of cancer. Given the difficulties of dysplasia assessment in mucosal biopsies, and the molecular characteristics of ND-BE, this technique should be considered for treatment of all BE patients, including those with ND or LGD. Post-ablation neo-squamous epithelium reveals no molecular abnormalities, and is biologically stable. Given that prospective randomized controlled trials of ablative therapy for ND-BE aiming at reducing EAC incidence and mortality are unlikely to be completed in the near future, endoscopic ablation is a valid management option. The success of RFA in achieving safe, uniform, reliable, and predictable elimination of BE allows surgeons to combine fundoplication with RFA. Currently, there is no type of treatment for dysplastic or non-dysplastic BE that achieves a complete response in 100% of patients, eliminates all risk of developing cancer, results in zero adverse events, is less expensive in terms of absolute costs than surveillance, is durable for 20+ years, or eliminates the need for surveillance. Regardless, RFA shows established safety, efficacy, durability, and cost-effective profiles that should be considered in the management of patients with non-dysplastic or low-grade dysplastic BE.

Endoscopic mucosal resection for staging and therapy of adenocarcinoma of the esophagus, gastric cardia, and upper gastric third

Minamally invasive endoscopic resection techniques allow definitive histological staging for dysplasia and early cancer and in many cases curative treatment. In Barrett's esophagus with High Grade Dysplasia (HGD) or early mucosal cancer, endoscopic mucosal resection (EMR) should be considered both as diagnostic and therapeutic first line procedure, with the possibility to repeat the procedure in case of residual Barrett's dysplasia or mucosal cancer. In early cancer of the the submucosa, surgical resection should be discussed. Endoscopic submucosal dissection (ESD) is a useful therapeutic option for HGD or early cancer in the squamous epithelium of the esophagus or in the stomach when en bloc resection is needed in large lesions.