Buried Barrett's epithelium following photodynamic therapy shows reduced crypt proliferation and absence of DNA content abnormalities

Barrett's Esophagus and Associated Dysplasia

Early detection of dysplasia and effective management are critical steps in halting neoplastic progression in patients with Barrett's esophagus (BE). This review provides a contemporary overview of the BE-related dysplasia, its role in guiding surveillance and management, and discusses emerging diagnostic and therapeutic approaches that might further enhance patient management. Novel, noninvasive techniques for sampling and surveillance, adjunct biomarkers for risk assessment, and their limitations are also discussed.

An Endoscopic and Histologic Study on Healing of Radiofrequency Ablation Wounds in Patients With Barrett's Esophagus

INTRODUCTION

Radiofrequency ablation (RFA) of Barrett's esophagus (BE) inflicts a wound spanning 3 epithelial types (stratified squamous, Barrett's metaplasia, gastric epithelium), yet the esophageal injury heals almost completely with squamous epithelium. Knowledge of how this unique wound heals might elucidate mechanisms underlying esophageal metaplasia. We aimed to prospectively and systematically characterize the early endoscopic and histologic features of RFA wound healing.

METHODS

Patients with nondysplastic BE had endoscopy with systematic esophageal photographic mapping, biopsy, and volumetric laser endomicroscopy performed before and at 1, 2, and 4 weeks after RFA.

RESULTS

Seven patients (6 men; mean age 56.1 ± 10.9 years) completed this study. Squamous re-epithelialization of RFA wounds did not only progress exclusively through squamous cells extending from the proximal wound edge but also progressed through islands of squamous epithelium sprouting throughout the ablated segment. Volumetric laser endomicroscopy revealed significant post-RFA increases in subepithelial glandular structures associated with the squamous islands. In 2 patients, biopsies of such islands revealed newly forming squamous epithelium contiguous with immature-appearing squamous cells arising from esophageal submucosal gland ducts. Subsquamous intestinal metaplasia (SSIM) was found in biopsies at 2 and/or 4 weeks after RFA in 6 of 7 patients.

DISCUSSION

RFA wounds in BE are re-epithelialized, not just by squamous cells from the proximal wound margin but by scattered squamous islands in which esophageal submucosal gland duct cells seem to redifferentiate into the squamous progenitors that fuel squamous re-epithelialization. SSIM can be found in most patients during the healing process. We speculate that this SSIM might underlie Barrett's recurrences after apparently successful eradication.

Surgery versus radical endotherapies for early cancer and high-grade dysplasia in Barrett's oesophagus

BACKGROUND

Barrett's oesophagus is one of the most common pre-malignant lesions in the world. Currently the mainstay of therapy is surgical management of advanced cancer but this has improved the five-year survival very little since the 1980s. As a consequence, improved survival relies on early detection through endoscopic surveillance programmes. Success of this strategy relies on the fact that late-stage pre-malignant lesions or very early cancers can be cured by intervention. Currently there is considerable controversy over which method is best: that is conventional open surgery or endotherapy (techniques involving endoscopy).

OBJECTIVES

We used data from randomised controlled trials (RCTs) to examine the effectiveness of endotherapies compared with surgery in people with Barrett's oesophagus, those with early neoplasias (defined as high-grade dysplasia (HGD) and those with early cancer (defined as carcinoma in-situ, superficially invasive, early cancer or superficial cancer T-1m (T1-a) and T-1sm (T1-b)).

SEARCH METHODS

We used the Cochrane highly sensitive search strategy to identify RCTs in MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), ISI Web of Science, EBMR, Controlled Trials mRCT and ISRCTN, and LILACS, in July and August 2008. The searches were updated in 2009 and again in April 2012.

SELECTION CRITERIA

Types of studies: RCTs comparing endotherapies with surgery in the treatment of high-grade dysplasia or early cancer. All cellular types of cancer were included (i.e. adenocarcinomas, squamous cell carcinomas and more unusual types) but will be discussed separately.

TYPES OF PARTICIPANTS

patients of any age and either gender with a histologically confirmed diagnosis of early neoplasia (HGD and early cancer) in Barrett's or squamous lined oesophagus. Types of interventions; endotherapies (the intervention) compared with surgery (the control), all with curative intent.

DATA COLLECTION AND ANALYSIS

Reports of studies that meet the inclusion criteria for this review would have been analysed using the methods detailed in Appendix 9.

MAIN RESULTS

We did not identify any studies that met the inclusion criteria. In total we excluded 13 studies that were not RCTs but that compared surgery and endotherapies.

AUTHORS' CONCLUSIONS

This Cochrane review has indicated that there are no RCTs to compare management options in this vital area, therefore trials should be undertaken as a matter of urgency. The problems with such randomised methods are standardising surgery and endotherapies in all sites, standardising histopathology in all centres, assessing which patients are fit or unfit for surgery and making sure there are relevant outcomes for the study (i.e. long-term survival (over five or more years)) and no progression of HGD.

No Barrett's-No Cancer: A Proposed New Paradigm for Prevention of Esophageal Adenocarcinoma

Esophageal adenocarcinoma is inflammation-associated cancer with a recognizable preneoplastic stage, Barrett's. Barrett's describes the metaplastic transformation of esophageal squamous mucosa into columnar epithelium that typically results secondary to mucosal damage caused by acidic gastroduodenal reflux. Continued acid reflux may then result in mucosal inflammation which results in progressive inflammation-induced genetic instability that may eventuate in esophageal adenocarcinoma. Barrett's is the only recognized precursor lesion to esophageal carcinoma. Barrett's mucosa is unique among preneoplastic lesions; ablation therapy results in restitution of a squamous epithelium reducing or eliminating accumulated genetic instabilities and resetting the biological clock progressing toward invasive cancer. However, recurrence of Barrett's after ablation is common. We propose that both Barrett's and recurrence of Barrett's after ablation can be prevented and discuss how current approaches to therapy for gastroesophageal reflux disease, for Barrett's screening, chemoprevention, and ablation therapy all might be reconsidered. We propose (1) improved approaches to Barrett's prevention, (2) universal Barrett's screening by linking Barrett's screening to colon cancer screening, (3) ablation of all Barrett's mucosa along with (4) acid-suppressive-antireflux therapy tailored to prevent development of Barrett's or the recurrence of Barrett's after ablation therapy. We propose that ultimately, treatment decisions for gastroesophageal reflux disease and prevention of Barrett's and esophageal carcinoma should be based on assessing and maintaining esophageal mucosal integrity. This will require development and verification of specific measurements that reliably correlate with prevention of Barrett's. We outline the new research and technical advances needed to cost-effectively achieve these goals.

Subsquamous intestinal metaplasia is common in treatment-naïve Barrett's esophagus

BACKGROUND AND AIMS

Barrett's intestinal metaplasia may extend beneath normal squamous epithelium at the squamocolumnar junction (SCJ) and therefore escape surveillance biopsy sampling. The prevalence of subsquamous intestinal metaplasia (SSIM) in patients undergoing Barrett's esophagus (BE) surveillance is unknown. Our aim was to examine the prevalence and distribution of SSIM proximal to the SCJ in patients undergoing BE surveillance.

METHODS

We enrolled consecutive patients with biopsy specimen-proven BE. Biopsy specimens were obtained from the squamous epithelium at 5 mm and 10 mm above the SCJ. The primary outcomes were the proportion of patients with SSIM at each level. We further assessed factors associated with SSIM.

RESULTS

We examined 515 squamous epithelial biopsy specimens from 106 BE patients (95% men; mean age, 66 years) with a mean Barrett's length of 3.0 cm. SSIM was present in 39% at 5 mm (95% CI, 29.4-48.6) and 21% (95% CI, 11.7-32.1) at 10 mm proximal to the SCJ. Among all biopsy specimens, 13% (95% CI, 10.6-16.6) contained SSIM: 17% (95% CI, 13-21.6) of biopsy samples at 5 mm and 8% (95% CI, 4.3-12.2) at 10 mm proximal to the SCJ. SSIM was more common in the anterior/right lateral position compared with the posterior/left lateral position (21% vs 11%, P = .001). None of the biopsy specimens showed dysplasia. Length of BE or duration of reflux symptoms were not associated with the presence of SSIM.

CONCLUSIONS

This cross-sectional study found a surprisingly high proportion of SSIM in treatment-naïve patients proximal to the SCJ. These findings raise questions regarding BE management and the prevalence of SSIM in normal-appearing esophagus.

Influence and mechanism of 5-aminolevulinic acid-photodynamic therapy on the metastasis of esophageal carcinoma

BACKGROUD

Photodynamic therapy (PDT) for the treatment of esophageal cancer was more and more popularly used since it was approved for the treatment of advanced esophageal cancer in 1996. It has been reported to influence the tumor growth and metastasis via a variety of signaling pathways, but its mechanism remains to be further studied. This research studied the effects of ALA-PDT on esophageal carcinoma in vitro and in vivo, discovering its molecular regulating mechanism and the way to enhence the PDT effect.

METHODS

Eca-109 cells were incubated with a medium containing EGFR tyrphostin AG1478 or PI3K inhibitor LY294002, then with ALA, and the cells were irradiated with the laser 6h later. The cell viability was measured with MTT assay, and the migration ability was detected by transwell experiments 24h post-ALA-PDT. The gene and protein expression on EGFR/PI3K/AKT signaling pathway was analyzed by realtime PCR and Western blotting respectively. Then, RFP-Eca-109 burdened nude mice model was constructed, and were treated with ALA-PDT when the tumor volume reached 150-350mm³. The gene and protein expression were analyzed 24h and 50days post-ALA-PDT.

RESULTS

Our study showed that ALA-PDT respectively combined with AG1478, LY294002 could synergistically reduce the growth and migration ability of the Eca-109 cells in vitro and significantly down-regulate the protein expression of EGFR/PI3K and PI3K/AKT, meanwhile, significantly down-regulate the gene expression of EGFR when combining with AG1478. Forthermore, ALA-PDT could significantly decrease the tumor growth and metastasis and down-regulate the gene expression of EGFR and the protein expression of EGFR and PI3K in the tumor of mice.

CONCLUSION

This study revealed a molecular mechanism of ALA-PDT and developed a new modality application of therapy, by combining ALA-PDT with small molecular inhibitors, for better effect in the clinical practice of esophageal carcinoma.

Endoscopic Management of Early Esophagogastric Cancer

Esophagogastric cancer accounts for the second most common cause of cancer-related mortality worldwide. Significant efforts have been made to detect these malignancies at an earlier stage through the implementation of screening programs in high-risk individuals using advanced diagnostic techniques. Endoscopic management techniques, such as endoscopic mucosal resection and endoscopic submucosal dissection, have consistently demonstrated excellent outcomes in the management of these lesions. These techniques are associated with a lower risk of morbidity and mortality when compared with traditional surgical management.

Barrett's Esophagus: A Comprehensive and Contemporary Review for Pathologists

This review provides a summary of our current understanding of, and the controversies surrounding, the diagnosis, pathogenesis, histopathology, and molecular biology of Barrett's esophagus (BE) and associated neoplasia. BE is defined as columnar metaplasia of the esophagus. There is worldwide controversy regarding the diagnostic criteria of BE, mainly with regard to the requirement to histologically identify goblet cells in biopsies. Patients with BE are at increased risk for adenocarcinoma, which develops in a metaplasia-dysplasia-carcinoma sequence. Surveillance of patients with BE relies heavily on the presence and grade of dysplasia. However, there are significant pathologic limitations and diagnostic variability in evaluating dysplasia, particularly with regard to the more recently recognized unconventional variants. Identification of non-morphology-based biomarkers may help risk stratification of BE patients, and this is a subject of ongoing research. Because of recent achievements in endoscopic therapy, there has been a major shift in the treatment of BE patients with dysplasia or intramucosal cancer away from esophagectomy and toward endoscopic mucosal resection and ablation. The pathologic issues related to treatment and its complications are also discussed in this review article.

Detection of buried Barrett's glands after radiofrequency ablation with volumetric laser endomicroscopy

BACKGROUND AND AIMS

The prevalence and clinical relevance of buried Barrett's glands (BB) after radiofrequency ablation (RFA) in Barrett's esophagus (BE) are debated. Recent optical coherence tomography studies demonstrated a high prevalence of BBs. Direct histological correlation, however, has been lacking. Volumetric laser endomicroscopy (VLE) is a second-generation optical coherence tomography system capable of scanning a large surface of the esophageal wall layers with low-power microscopy resolution. The aim was to evaluate whether post-RFA subsquamous glandular structures (SGSs), detected with VLE, actually correspond to BBs by pursuing direct histological correlation with VLE images.

METHODS

In vivo VLE was performed to detect SGSs in patients with endoscopic regression of BE post-RFA. A second in vivo VLE scan was performed to confirm correct delineation of the SGSs. After endoscopic resection, the specimens were imaged ex vivo with VLE. Extensive histological sectioning of SGS areas was performed, and all histology slides were evaluated by an expert BE pathologist.

RESULTS

Seventeen patients underwent successful in vivo VLE (histological diagnosis before endoscopic treatment: early adenocarcinoma in 8 patients and high-grade dysplasia in 9). In 4 of 17 patients, no SGSs were identified during VLE, and a random resection was performed. In the remaining 13 patients (76%), VLE detected SGS areas, which were all confirmed on a second in vivo VLE scan and subsequently resected. Most SGSs identified by VLE corresponded to normal histological structures (eg, dilated glands and blood vessels). However, 1 area containing BBs was found on histology. No specific VLE features to distinguish between BBs and normal SGSs were identified.

CONCLUSIONS

VLE is able to detect subsquamous esophageal structures. One area showed BBs beneath endoscopically normal-appearing neosquamous epithelium; however, most post-RFA SGSs identified by VLE correspond to normal histological structures. (

CLINICAL TRIAL REGISTRATION NUMBER

NTR4056.).

Endoscopic Management of Early Esophageal Cancer

The absolute incidence of esophageal adenocarcinoma has increased 7-fold over the past 5 decades, and esophageal adenocarcinoma is the most rapidly increasing epithelial malignancy in the United States. The incidence of early esophageal cancer has also increased proportionately. In the past decade, radiofrequency ablation has become the standard first-line therapy for high-grade dysplasia when found in the precursor lesion to esophageal adenocarcinoma, Barrett's esophagus. Success in the endoscopic management of high-grade dysplasia has furthered efforts to treat early esophageal cancers endoscopically. Although surgery remains the mainstay of treatment for more advanced tumors, national guidelines now recommend endoscopic mucosal resection followed by radiofrequency ablation for intramucosal carcinomas and T1a cancers. T1b cancers represent a more challenging group-very good results have been reported in highly selected subsets of patients with T1b tumors; however, many recommendations favor individualization or a surgical approach for this stage. This review examines the current data and recommendations regarding the endoscopic management of early esophageal adenocarcinomas.

Sixteen-year follow-up of Barrett's esophagus, endoscopically treated with argon plasma coagulation

OBJECTIVE

The thermal destruction of non-dysplastic Barrett's esophagus (BE) and its replacement by squamous epithelium is an attractive, but unproven strategy to avoid further development of dysplasia or cancer. The goal of this study was to estimate the persistence of restoration of squamous epithelium and the risk of cancer in BE that was eradicated using argon plasma coagulation (APC) in the absence of high-grade dysplasia, 16 years after its application.

DESIGN

We followed 32 patients with BE who underwent eradication of metaplastic epithelium using APC, up to 16 years later.

RESULTS

At the end of the initial treatment, 25 of 32 patients (78%) had complete endoscopic eradication, there was partial squamous re-epithelialization in four patients (13%) and it was absent in three patients (9%). We observed buried metaplastic glands under new squamous epithelium in 6 of the 25 patients who had complete endoscopic eradication. At follow-up, sustained complete endoscopic eradication was observed in 16 of 32 patients (50%), partial eradication in 11 of 32 patients (35%); there were two patients (6%) lost to follow-up and three patients (9%) developed esophageal adenocarcinoma. Two of the latest cases arose from the buried glands under neosquamous epithelium after complete eradication and one arose from a small remaining Barrett's segment.

CONCLUSIONS

We observed long-term re-epithelialization in the majority of patients who had previously had complete eradication of Barrett's esophagus. This did not provide protection against cancer development, as the incidence of cancers arising from buried glands or from residual Barrett's esophagus was similar to that observed in patients undergoing no specific treatment.

Markers suggest reduced malignant potential of subsquamous intestinal metaplasia compared with Barrett's esophagus

Esophageal subsquamous intestinal metaplasia (SSIM) is frequently observed in patients with Barrett's esophagus (BE) and can also be found in patients after endoscopic ablative treatments for dysplastic BE. While these 'buried glands' appear identical to BE glands, features of SSIM and its malignant potency have yet to be fully elucidated. To determine differences in malignant potential between nondysplastic BE and SSIM, the Automated Cellular Imaging System was used to assess and compare changes in DNA content between SSIM and BE. Samples were further immunostained for Ki67 and Lgr5 to gauge general proliferative and possible stem cell features, respectively, in SSIM cells compared with BE glands. No significant differences were found between SSIM and BE with regards to DNA ploidy aberrance. However, significant differences were noted between SSIM and BE upon immunohistochemical analysis. SSIM was found to be negative for both Ki67 and Lgr5 while BE was positive for both markers. SSIM cells appear to be relatively quiescent and behave differently from BE, suggesting a reduced proclivity toward cancer progression.

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.

Subsquamous intestinal metaplasia after ablation of Barrett's esophagus: frequency and importance

PURPOSE OF REVIEW

This article reviews reports on the prevalence of subsquamous intestinal metaplasia (SSIM) in patients with Barrett's esophagus, and the implications of SSIM in the neoplastic progression of Barrett's esophagus to esophageal adenocarcinoma.

RECENT FINDINGS

Endoscopic eradication therapy for dysplastic Barrett's esophagus has become an encouraging alternative to esophagectomy or continued endoscopic surveillance. However, the presence of SSIM before and after ablation is concerning because this tissue may have potential for malignant progression, is not visible by conventional endoscopy, and may evade detection by random esophageal biopsy sampling methods. Advances in endoscopic high-resolution three-dimensional optical coherence tomography recently have revealed SSIM in a majority of patients both before and after complete eradication of Barrett's esophagus by radiofrequency ablation. Studies suggest that although cells of Barrett's glands are highly proliferative, the cells of these buried glands are more dormant. Nevertheless, the malignant potential of SSIM cells remains undetermined.

SUMMARY

Novel endoscopic imaging demonstrates that SSIM is present in the majority of patients with Barrett's esophagus, both before and after ablative therapy. Although these subsquamous cells exhibit less proliferative activity than those of typical surface Barrett's glands, the malignant potential of the buried glands, especially when challenged by injurious factors, remains largely unknown. Future methods to detect subsurface dysplasia will be needed.

Managing Barrett's esophagus with radiofrequency ablation

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

Endoscopic therapy for Barrett's esophagus and early esophageal adenocarcinoma

Endoscopic therapy for Barrett's esophagus is feasible and likely to decrease the future risk of development of esophageal adenocarcinoma. The most commonly used therapy is radiofrequency ablation, which has been shown to produce reproducible superficial injury in the esophagus. Other thermal therapies include multipolar coagulation, argon plasma coagulation, and thermal laser therapy. The other end of the ablative spectrum includes cryotherapy, which involves freezing tissue to produce mucosal necrosis. Photodynamic therapy has been used to photochemically eliminate abnormal mucosa. Endoscopic therapy has been demonstrated to be effective in high-risk situations such as Barrett's esophagus with high-grade dysplasia.

Surgery versus radical endotherapies for early cancer and high-grade dysplasia in Barrett's oesophagus

BACKGROUND

Barrett's oesophagus is one of the most common pre-malignant lesions in the world. Currently the mainstay of therapy is surgical management of advanced cancer but this has improved the five-year survival very little since the 1980s. As a consequence, improved survival relies on early detection through endoscopic surveillance programmes. Success of this strategy relies on the fact that late-stage pre-malignant lesions or very early cancers can be cured by intervention. Currently there is considerable controversy over which method is best: that is conventional open surgery or endotherapy (techniques involving endoscopy).

OBJECTIVES

We used data from randomised controlled trials (RCTs) to examine the effectiveness of endotherapies compared with surgery in people with Barrett's oesophagus, those with early neoplasias (defined as high-grade dysplasia (HGD) and those with early cancer (defined as carcinoma in-situ, superficially invasive, early cancer or superficial cancer T-1m (T1-a) and T-1sm (T1-b)).

SEARCH METHODS

We used the Cochrane highly sensitive search strategy to identify RCTs in MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), ISI Web of Science, EBMR, Controlled Trials mRCT and ISRCTN, and LILACS, in July and August 2008. The searches were updated in 2009 and again in April 2012.

SELECTION CRITERIA

Types of studies: RCTs comparing endotherapies with surgery in the treatment of or early cancer. All cellular types of cancer were included (i.e. adenocarcinomas, squamous cell carcinomas and more unusual types) but will be discussed separately.

TYPES OF PARTICIPANTS

patients of any age and either gender with a histologically confirmed diagnosis of early neoplasia (HGD and early cancer) in Barrett's or squamous lined oesophagus.Types of interventions; endotherapies (the intervention) compared with surgery (the control), all with curative intent.

DATA COLLECTION AND ANALYSIS

Reports of studies that meet the inclusion criteria for this review would have been analysed using the methods detailed in Appendix 9.

MAIN RESULTS

We did not identify any studies that met the inclusion criteria. In total we excluded 13 studies that were not RCTs but that compared surgery and endotherapies.

AUTHORS' CONCLUSIONS

This Cochrane review has indicated that there are no RCTs to compare management options in this vital area, therefore trials should be undertaken as a matter of urgency. The problems with such randomised methods are standardising surgery and endotherapies in all sites, standardising histopathology in all centres, assessing which patients are fit or unfit for surgery and making sure there are relevant outcomes for the study (i.e. long-term survival (over five or more years)) and no progression of HGD.

Molecular biomarkers and ablative therapies for Barrett's esophagus

Barrett's esophagus is the major risk factor for esophageal adenocarcinoma. Endoscopic interventions that ablate Barrett's esophagus mucosa lead to replacement with a new squamous (neosquamous) mucosa, but it can be difficult to achieve complete ablation. Knowing whether cancer is less likely to develop in neosquamous mucosa or residual Barrett's esophagus after ablation is critical for determining the efficacy of treatment. This issue can be informed by assessing biomarkers that are associated with an increased risk of progression to adenocarcinoma. Although there are few postablation biomarker studies, evidence suggests that neosquamous mucosa may have a reduced risk of adenocarcinoma in patients who have been treated for dysplasia or cancer, but some patients who do not have complete eradication of nondysplastic Barrett's esophagus may still be at risk. Biomarkers could be used to optimize endoscopic surveillance strategies following ablation, but this needs to be assessed by clinical studies and economic modeling.

Medical and endoscopic management of high-grade dysplasia in Barrett's esophagus

The management of high-grade dysplasia in Barrett's esophagus has clearly changed over recent years. The risk of cancer development is still substantial, with about one in three patients developing cancer, but a number of patients do not develop cancer. The nature of high-grade dysplasia has also been genetically elucidated with more evidence of chromosomal instability being present at this stage than previously thought. Therapy of the condition has evolved more toward endoscopic therapy, given the good results of radio-frequency ablation and photodynamic therapy in eliminating dysplasia and decreasing cancer development in randomized controlled trial. The best candidates for treatment include compliant patients that have relatively short segments of Barrett's esophagus, an anatomically straight segment, lack of nodularity, and an intact p16. However, even with excellent long-term results similar to surgical resection, the risk of recurrence is present in over 14% of patients, which indicates that there will be a need to continue surveillance endoscopy in these patients.

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.

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.

Buried metaplasia after endoscopic ablation of Barrett's esophagus: a systematic review

OBJECTIVES

Endoscopic ablation of Barrett's esophagus can bury metaplastic glands under a layer of neosquamous epithelium. To explore the frequency and importance of buried metaplasia, we have conducted a systematic review of reports on endoscopic ablation.

METHODS

We performed computerized and manual searches for articles on the results of photodynamic therapy (PDT) and radiofrequency ablation (RFA) for Barrett's esophagus. We extracted information on the number of patients treated, biopsy protocol, biopsy depth, and frequency of buried metaplasia.

RESULTS

We found 9 articles describing 34 patients with neoplasia appearing in buried metaplasia (31 after PDT). We found five articles describing a baseline prevalence of buried metaplasia (before ablation) ranging from 0% to 28%. In 22 reports on PDT for 953 patients, buried metaplasia was found in 135 (14.2%); in 18 reports on RFA for 1,004 patients, buried metaplasia was found in only 9 (0.9%). A major problem limiting the conclusions that can be drawn from these reports is that they do not describe specifically how frequently biopsy specimens contained sufficient subepithelial lamina propria to be informative for buried metaplasia.

CONCLUSIONS

Endoscopic ablation can bury metaplastic glands with neoplastic potential but, even without ablation, buried metaplasia often is found in areas where Barrett's epithelium abuts squamous epithelium. Buried metaplasia is reported less frequently after RFA than after PDT. However, available reports do not provide crucial information on the adequacy of biopsy specimens and, therefore, the frequency and importance of buried metaplasia after endoscopic ablation remain unclear.

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.

Long-term remission of nondysplastic Barrett's esophagus after multipolar electrocoagulation ablation: report of 139 patients with 10 years of follow-up

BACKGROUND

Ablation of Barrett's esophagus (BE) has been advocated as a method to eliminate the risk of malignant transformation of BE.

OBJECTIVE

To provide longer follow-up and determine safety and efficacy of multipolar ablation for nondysplastic BE.

DESIGN

Prospective cohort study.

SETTING

Gastroenterology Unit at the Policlinica Metropolitana, a tertiary care center in Caracas, Venezuela.

PATIENTS

One hundred sixty-six patients with nondysplastic BE and histologic evidence of intestinal metaplasia.

INTERVENTIONS

Patients underwent multipolar electrocoagulation ablation therapy to areas of BE identified with magnification chromoendoscopy. The identified areas were treated with a 50-W energy source and a 7F "gold" probe. After complete ablation, patients were followed on an annual basis with magnification chromoendoscopy. At annual visits, biopsy specimens were taken in areas identified at baseline as BE. Targeted biopsy specimens were taken in areas of recurrent BE identified by using magnification chromoendoscopy.

MAIN OUTCOME MEASUREMENTS

Mortality, incidence of recurrent BE, incidence of adenocarcinoma in ablated BE, and morbidity associated with multipolar electrocoagulation.

RESULTS

One hundred sixty-six patients were recruited for the study; 139 completed at least 10 years of follow-up. Complications developed in less than 5% of patients, all of which were minor. Recurrent BE occurred in less than 5% of patients. No adenocarcinoma or high-grade dysplasia of the esophagus developed in any of the patients.

LIMITATION

Uncontrolled clinical trial.

CONCLUSIONS

Long-term follow-up of ablation of BE with multipolar electrocoagulation ablation therapy indicates that this is a safe, effective method to ablate BE over the long term.

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.

The role of radiofrequency ablation in the management of Barrett's esophagus

Studies in the last several years have consistently shown radiofrequency ablation (RFA) to be effective, safe, and well tolerated in the treatment of nondysplastic and dysplastic Barrett's esophagus (BE). The results found at academic medical centers have been reproduced in the community setting. RFA provides a safe and cost-effective alternative to surgery or surveillance in the management of high-grade dysplasia (HGD). RFA should be given serious consideration as first-line therapy for HGD. This article reviews the evidence behind RFA to differentiate it from other management strategies in terms of efficacy, durability, safety, tolerability, and cost-effectiveness. The role of RFA in the management of BE is described, including endoscopic resection. Future directions are identified for research that will help to better define the role of RFA in the management of BE.

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."

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.

The role of epidermal growth factor receptor in photodynamic therapy: a review of the literature and proposal for future investigation

The epidermal growth factor receptor (EGFR) pathway seems to be an important contributor to the antiproliferative response to photodynamic therapy (PDT), in terms of cell death, apoptosis and tumour destruction. We reviewed all preclinical investigations in the scientific literature on the role of the EGFR pathway in PDT. A systematic search of Medline-indexed references up to March 2010 using the recommended strategies for Medline information retrieval and identifying relevant studies from systematic reviews, revealed 16 full articles that were exhaustively analysed. EGFR inhibition/degradation appeared to be a major effect of PDT in all investigations. PDT was found to result in a time-dependent reduction of EGFR expression, inhibition of tyrosine phosphorylation and induction of apoptosis during the regression of tumours. Within the time period of the PDT reaction, normal and malignant cells lose their responsiveness to EGF. The ERK1/2 and EGFR-PI3K-Akt pathways seem to be involved in cellular survival after PDT. Pharmacotherapy and immunotherapy to block EGFR activity combined with PDT seem to be very effective in reducing malignant tumours in vivo. The effect of PDT is associated with inactivation of the EGFR pathway, but biochemical and cellular phenomena are important and scarcely investigated. EGFR inhibitors and PDT act synergistically, and this is highly relevant for clinical use.

New Endoscopic Techniques: Challenges and Opportunities for Surgical Pathologists

In recent years, significant clinical and technological advances have been made in endoscopic methods for diagnosis and treatment of early gastrointestinal neoplasms. However, essential information related to these novel techniques and their implications for practicing surgical pathologists have largely been missing in the general pathology literature. This article provides a general introduction to these novel therapeutic and diagnostic methods, and discusses their indications, contraindications, and potential limitations. The article aims to enable surgical pathologists to interact more efficiently with basic scientists and clinical colleagues to help implement and improve the existing clinical methods and to advance the new technologies.

Surgery versus radical endotherapies for early cancer and high grade dysplasia in Barrett's oesophagus

BACKGROUND

Barrett's oesophagus is one of the most common premalignant lesions in the world. Currently the mainstay of therapy is surgical management of advanced cancer but this has improved the five-year survival very little in the last 30 years. As a consequence, improved survival relies on early detection through endoscopic surveillance programmes. Success of this strategy relies on the fact that late stage premalignant lesions or very early cancers can be cured by intervention. Currently there is considerable controversy over which method is best: i.e. conventional open surgery or endotherapy (techniques involving endoscopy).

OBJECTIVES

We used data from randomised controlled trials to examine the effectiveness of endotherapies compared with surgery, in people with Barrett's Oesophagus; those with early neoplasias (defined as high grade dysplasia (HGD), and those with early cancer (defined as carcinoma in-situ, superficially invasive, early cancer or superficial cancer T-1m (T1-a) and T-1sm (T1-b)).

SEARCH STRATEGY

We used the Cochrane highly sensitive search strategy to identify randomised trials in MEDLINE, EMBASE, CENTRAL, ISI Web of Science, EBMR, Controlled Trials mRCT and ISRCTN and LILACS, in July and August 2008.

SELECTION CRITERIA

Types of studies: randomised controlled trials comparing endotherapies with surgery in the treatment of high grade dysplasia (HGD), or early cancer. All cellular types of cancer were included (i.e. adenocarcinomas, squamous cell carcinomas and more unusual types) but will be discussed separately.

TYPES OF PARTICIPANTS

patients of any age and either gender with a histologically confirmed diagnosis of early neoplasia (HGD and early cancer) in Barrett's or squamous lined oesophagus.Types of interventions; endotherapies (the intervention) compared with surgery (the control), all with curative intent.

DATA COLLECTION AND ANALYSIS

Reports of studies which meet the inclusion criteria for this review would have been analysed using the methods detailed in Appendix 9.

MAIN RESULTS

We did not identify any studies which met the inclusion criteria.

AUTHORS' CONCLUSIONS

This Cochrane review has indicated that there are no randomised control trials to compare management options in this vital area, therefore trials should be undertaken as a matter of urgency. The problems with such randomised methods are standardising surgery and endotherapies in all sites; standardising histopathology in all centres; assessing which patients are fit or unfit for surgery; and making sure there are relevant outcomes for the study i.e. long term survival (over five or more years) and no progression of high grade dysplasia.

Prevalence and predictors of recurrent neoplasia after ablation of Barrett's esophagus

BACKGROUND

The incidence and risk factors for recurrence of dysplasia after ablation of Barrett's esophagus (BE) have not been well defined.

OBJECTIVE

To determine the rate and predictors of dysplasia/neoplasia recurrence after photodynamic therapy (PDT) in BE.

SETTING

Retrospective analysis of a prospective cohort of BE patients seen at a specialized BE unit.

METHODS

Patients underwent a standard protocol assessment with esophagogastroduodenoscopy and 4-quadrant biopsies every centimeter at 3-month intervals after ablation. Recurrence was defined as the appearance of any grade of dysplasia or neoplasia after 2 consecutive endoscopies without dysplasia. Entry histology, demographics, length of BE, presence and length of diaphragmatic hernia, EMR, stricture formation, nonsteroidal anti-inflammatory drug use, smoking, and the presence of nondysplastic BE or squamous epithelium were assessed for univariate associations. Time-to-recurrence analysis was done by using Cox proportional hazards regression. A multivariate model was constructed to establish independent associations with recurrence.

RESULTS

A total of 363 patients underwent PDT with or without EMR. Of these, 261 patients were included in the final analysis (44 lost to follow-up, 46 had residual dysplasia, and 12 had no dysplasia at baseline). Indication for ablation was low-grade dysplasia (53 patients, 20%), high-grade dysplasia (152 patients, 58%), and intramucosal cancer (56 patients, 21%). Median follow-up was 36 months (interquartile range 18-79 months). Recurrence occurred in 45 patients. Median time to recurrence was 17 months (interquartile range 8-45 months). Significant predictors of recurrence on the multivariate model were older age (hazard ratio [HR] 1.04, P=.029), presence of residual nondysplastic BE (HR 2.88, P=.012), and a history of smoking (HR 2.68, P=.048).

LIMITATIONS

Possibility of missing prevalent dysplasia despite aggressive surveillance.

CONCLUSION

Recurrence of dysplasia/neoplasia after PDT ablation is associated with advanced age, smoking, and residual BE.

Biomarkers in Barrett's Esophagus

Biomarkers are substances that can be used to indicate normal or diseased states. In clinical settings, the term biomarker generally refers to a molecular marker produced by tissues whose detection heralds a diseased state. For patients with Barrett's esophagus, there are at least three clinical settings in which the use of molecular biomarkers has been proposed including 1) stratifying the risk of neoplastic progression, 2) serving as an adjunct to aid in the diagnosis of dysplasia, and 3) predicting response to ablative therapies. Although the routine clinical use of biomarkers in any of these clinical settings is not yet recommended, it seems reasonable to assume that biomarker validation studies will be carried out in the coming years and that movement into the clinics will be inevitable. This article reviews the current progress in using biomarkers in each of the clinical settings described above with a focus on the molecular biomarkers which have advanced the farthest toward use in routine clinical practice.

History, molecular mechanisms, and endoscopic treatment of Barrett's esophagus

This report is an adjunct to the American Gastroenterological Association Institute's medical position statement and technical review on the management of Barrett's esophagus, which will be published in the near future. Those documents will consider a number of broad questions on the diagnosis, clinical features, and management of patients with Barrett's esophagus, and the reader is referred to the technical review for an in-depth discussion of those topics. In this report, we review historical, molecular, and endoscopic therapeutic aspects of Barrett's esophagus that are of interest to clinicians and researchers.

Treatment for Barrett's oesophagus

BACKGROUND

Treatments for Barrett's oesophagus, the precursor lesion of adenocarcinoma, are available but whether these therapies effectively prevent the development of adenocarcinoma, and in some cases eradicate the Barrett's oesophagus segment, remains unclear.

OBJECTIVES

To summarise, quantify and compare the efficacy of pharmacological, surgical and endoscopic treatments for the eradication of dysplastic and non-dysplastic Barrett's oesophagus and prevention of these states from progression to adenocarcinoma.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library 2004, issue 4), MEDLINE (1966 to June 2008) and EMBASE (1980 to June 2008).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing medical, endoscopic or non-resectional surgical treatments for Barrett's oesophagus. The primary outcome measures were complete eradication of Barrett's and dysplasia at 12 months, and reduction in the number of patients progressing to cancer at five years or latest time point.

DATA COLLECTION AND ANALYSIS

Three authors independently extracted data and assessed the quality of the trials included in the analysis.

MAIN RESULTS

Sixteen studies, including 1074 patients, were included. The mean number of participants in the studies was small (n = 49; range 8 to 208). Most studies did not report on the primary outcomes. Medical and surgical interventions to reduce symptoms and sequelae of gastro-oesophageal reflux disease (GORD) did not induce significant eradication of Barrett's oesophagus or dysplasia. Endoscopic therapies (photodynamic therapy (PDT with aminolevulinic acid or porfimer sodium), argon plasma coagulation (APC) and radiofrequency ablation (RFA)) all induced regression of Barrett's oesophagus and dysplasia. The data for photodynamic therapy were heterogeneous with a mean eradication rate of 51% for Barrett's oesophagus and between 56% and 100% for dysplasia, depending on the treatment regimens. The variation in photodynamic therapy eradication rates for dysplasia was dependent on the drug, source and dose of light. Radiofrequency ablation resulted in eradication rates of 82% and 94% for Barrett's oesophagus and dysplasia respectively, compared to a sham treatment. Endoscopic treatments were generally well tolerated, however all were associated with some buried glands, particularly following argon plasma coagulation and photodynamic therapy, as well as photosensitivity and strictures induced by porfimer sodium based photodynamic therapy in particular.

AUTHORS' CONCLUSIONS

Despite their failure to eradicate Barrett's oesophagus, the role of medical and surgical interventions to reduce the troubling symptoms and sequelae of GORD is not questioned. Whether therapies for GORD reduce the cancer risk is not yet known. Ablative therapies have an increasing role in the management of dysplasia within Barrett's and current data would favour the use of radiofrequency ablation compared with photodynamic therapy. Radiofrequency ablation has been shown to yield significantly fewer complications than photodynamic therapy and is very efficacious at eradicating both dysplasia and Barrett's itself. However, long-term follow-up data are still needed before radiofrequency ablation can be used in routine clinical care without the need for very careful post-treatment surveillance. More clinical trial data and in particular randomised controlled trials are required to assess whether or not the cancer risk is reduced in routine clinical practice.

The role of photodynamic therapy in the esophagus

Photodynamic therapy (PDT) is a drug and device therapy using photosensitizer drugs activated by laser light for mucosal ablation. Porfimer sodium PDT has been used extensively with proven long-term efficacy and durability for the ablation of Barrett esophagus and high-grade dysplasia. and early esophageal adenocarcinoma. However, continued use is hampered by an associated stricture risk and prolonged photosensitivity (4-6 weeks). Promising single-center European studies using other forms of PDT, such as aminolevulinic acid PDT, have not been replicated elsewhere, limiting the widespread use of other forms of PDT. Future use of PDT in esophageal disease depends on the development of improved dosimetry and patient selection to optimize treatment outcomes, while minimizing adverse events and complications.

Barrett's Esophagus and esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has risen dramatically over the past three decades in western countries. The importance of Barrett's esophagus (BE) derives from its potential to transform to adenocarcinoma. BE is characterized by endoscopically recognized displacement of the squamocolumnar junction proximal to the gastroesophageal junction, with replacement of squamous mucosa with columnar lined mucosa. Adenocarcinomas of the esophagus appear to arise from Barrett's mucosa through progressive degrees of dysplasia, but the pathogenesis and natural history of this process are still unclear. Much of our knowledge regarding BE and the risk of EAC is based on observational and cross-sectional analyses, and recommendations regarding management have traditionally represented "expert opinion." The past few years have seen an explosion in new information and the initiation of longitudinal studies to define the risk of adenocarcinoma in BE, the identification of predictive and prognostic markers of cancer risk, sensitive and cost-effective methods of surveillance, and methods of management of dysplasia and early neoplasia including disease prevention.

Advanced pathology under squamous epithelium on initial EMR specimens in patients with Barrett's esophagus and high-grade dysplasia or intramucosal carcinoma: implications for surveillance and endotherapy management

BACKGROUND

Prior studies report the presence of buried Barrett's epithelium under squamous mucosa after endoscopic ablative therapies for Barrett's esophagus (BE) with high-grade dysplasia (HGD) or intramucosal carcinoma (IMC). However, there still exists significant controversy about whether these glands represent a neoablative phenomenon or predate endoscopic therapy.

OBJECTIVE

To determine the prevalence of buried BE underneath squamous epithelium on initial mucosectomy specimens for complete Barrett's eradication EMR (CBE-EMR) for BE with HGD or IMC.

DESIGN

Retrospective double-blinded review.

SETTING

A tertiary-care academic referral center.

PATIENTS AND METHODS

Histopathology slides of all initial mucosectomy specimens for all patients who underwent CBE-EMR for BE with HGD or IMC at our center between August 2003 and February 2008 were reviewed retrospectively in a double-blinded fashion by 2 expert GI pathologists. None of the patients had undergone prior endoscopic ablative therapy for dysplastic BE.

MAIN OUTCOME MEASUREMENTS

The prevalence of buried BE underneath squamous epithelium in initial mucosectomy specimens from CBE-EMR for BE with HGD or IMC.

RESULTS

A total of 47 patients' initial mucosectomy slides were reviewed. The presence of Barrett's epithelium underneath the squamous resection margin (Z line) was identified in 13 of 47 patients (28%) at initial mucosectomy. The linear distance of the Barrett's epithelium from the resection's squamous margin ranged from 0.8 to 5.6 mm (mean 2.3 mm and median 1.9 mm). Histopathology revealed nondysplastic buried BE in 3 patients, HGD in 9 patients, and IMC in 1 patient. Thus, 10 of 13 patients (21% of 47 total) had buried glands with advanced pathology (HGD or IMC), whereas 3 of 13 (6% of 47 total) had specialized intestinal metaplasia without dysplasia.

LIMITATIONS

A single-center, modest study population size.

CONCLUSIONS

Our results revealed a significant prevalence of buried Barrett's epithelium with or without dysplasia under squamous mucosa (squamocolumnar junction) on initial mucosectomy specimens. Given the neoplastic potential of BE, the presence of these subsquamous BE glands may affect the extent and adequacy of mucosal resection margins. Based on these findings, surveillance biopsies and ablative therapy should extend to 1 cm proximal to the endoscopically determined squamocolumnar junction.

Increased p53 expression in the malignant transformation of Barrett's esophagus is accompanied by an upward shift of the proliferative compartment

Neoplastic progression in Barrett's esophagus (BE) occurs by a multistep process associated with early molecular and morphological changes. This study evaluated cell proliferation and p53 expression and their correlation in the development and progression of esophageal adenocarcinoma. PCNA and p53 expressions were analyzed in biopsy samples by immunohistochemistry including patients with reflux esophagitis, BE, BE with concomitant esophagitis, Barrett's dysplasia, esophageal adenocarcinoma and a control group without any histological changes. Progressive increase in cell proliferation and p53 expression was found in the sequence of malignant transformation of the esophageal mucosa. While cell proliferation was significantly lower in the control group compared with all other groups, there was no increase in p53 expression of esophageal tissues that were negative for dysplasia. Dysplastic BE tissues revealed significantly higher cell proliferation and p53 expression levels compared to BE, reflux esophagitis or BE with concomitant esophagitis. Both, cell proliferation and p53 expression were significantly higher in adenocarcinoma compared to BE or Barrett's dysplasia. Interestingly, while just BE with concomitant esophagitis showed significantly higher p53 expression levels than BE, both, BE with concomitant esophagitis and reflux esophagitis revealed significantly higher cell proliferation levels compared to BE. Alterations of cell proliferation and p53 expression showed a strong correlation. Simultaneous activation of cell proliferation and p53 expression strongly suggest their association with esophageal epithelial tumor genesis and particularly, their specific role in the biology of esophageal adenocarcinoma. Quantification of these parameters in BE is thought to be useful to identify patients at higher risk for progression to adenocarcinoma.

Surgery versus radical endotherapies for early cancer and high grade dysplasia in Barrett's oesophagus

BACKGROUND

Barrett's oesophagus is one of the most common premalignant lesions in the world. Currently the mainstay of therapy is surgical management of advanced cancer but this has improved the five-year survival very little in the last 30 years. As a consequence, improved survival relies on early detection through endoscopic surveillance programmes. Success of this strategy relies on the fact that late stage premalignant lesions or very early cancers can be cured by intervention. Currently there is considerable controversy over which method is best: i.e. conventional open surgery or endotherapy (techniques involving endoscopy).

OBJECTIVES

We used data from randomised controlled trials to examine the effectiveness of endotherapies compared with surgery, in people with Barrett's Oesophagus; those with early neoplasias (defined as high grade dysplasia (HGD), and those with early cancer (defined as carcinoma in-situ, superficially invasive, early cancer or superficial cancer T-1m (T1-a) and T-1sm (T1-b)).

SEARCH STRATEGY

We used the Cochrane highly sensitive search strategy to identify randomized trials in MEDLINE, EMBASE, CENTRAL, ISI Web of Science, EBMR, Controlled Trials mRCT and ISRCTN and LILACS, in July and August 2008.

SELECTION CRITERIA

Types of studies: randomised controlled trials comparing endotherapies with surgery in the treatment of high grade dysplasia (HGD), or early cancer. All cellular types of cancer were included (i.e. adenocarcinomas, squamous cell carcinomas and more unusual types) but will be discussed separately.

TYPES OF PARTICIPANTS

patients of any age and either gender with a histologically confirmed diagnosis of early neoplasia (HGD and early cancer) in Barrett's or squamous lined oesophagus.Types of interventions; endotherapies (the intervention) compared with surgery (the control), all with curative intent.

DATA COLLECTION AND ANALYSIS

Reports of studies which meet the inclusion criteria for this review would have been analysed using the methods detailed in Appendix 9.

MAIN RESULTS

We did not identify any studies which met the inclusion criteria.

AUTHORS' CONCLUSIONS

This Cochrane review has indicated that there are no randomised control trials to compare management options in this vital area, therefore trials should be undertaken as a matter of urgency. The problems with such randomised methods are standardising surgery and endotherapies in all sites; standardising histopathology in all centres; assessing which patients are fit or unfit for surgery; and making sure there are relevant outcomes for the study i.e. no progression of high grade dysplasia or long term survival i.e. over five years.

New treatments, new challenges: pathology's perspective on esophageal carcinoma

While frank esophageal carcinoma rarely presents a diagnostic challenge, early lesions are often tricky to assess. This difficulty stems in part from drawbacks in the classification systems designed to stratify early lesions as a guide for deciding treatment. These systems are complex and wrought with specific pathologic challenges brought on by new treatment modalities. Such interventions as endoscopic mucosal resection, photodynamic therapy, and chemotherapy/radiation combinations present the pathologist with new histologic challenges that have a direct impact on patient care. In this article, we discuss staging issues pertinent to early cancers, histologic sequelae of various treatments, and how these factors affect the pathologist's role in evaluating esophageal carcinoma.