Optimizing endoscopic biopsy detection of early cancers in Barrett's high-grade dysplasia

Endoscopic Resection and Ablation for Early-Stage Esophageal Cancer

Endoscopic resection and ablation have become the preferred therapy for most patients with high-grade dysplasia or superficial esophageal cancer. Endoscopic therapy offers esophageal preservation with similar oncologic outcomes and significantly fewer complications compared with the alternative of esopahgectomy. The goal of endotherapy is eradication of all the premalignant intestinal metaplasia to minimize the risk for metachronous cancer development. Once accomplished, careful follow-up is necessary to address recurrent intestinal metaplasia or dysplasia and prevent long-term failure of an endoscopic approach in these patients.

Electrothermal MEMS fiber scanner for optical endomicroscopy

We report a novel MEMS fiber scanner with an electrothermal silicon microactuator and a directly mounted optical fiber. The microactuator comprises double hot arm and cold arm structures with a linking bridge and an optical fiber is aligned along a silicon fiber groove. The unique feature induces separation of resonant scanning frequencies of a single optical fiber in lateral and vertical directions, which realizes Lissajous scanning during the resonant motion. The footprint dimension of microactuator is 1.28 x 7 x 0.44 mm3. The resonant scanning frequencies of a 20 mm long optical fiber are 239.4 Hz and 218.4 Hz in lateral and vertical directions, respectively. The full scanned area indicates 451 μm x 558 μm under a 16 Vpp pulse train. This novel laser scanner can provide many opportunities for laser scanning endomicroscopic applications.

Quantitative analysis of high-resolution microendoscopic images for diagnosis of neoplasia in patients with Barrett's esophagus

BACKGROUND AND AIMS

Previous studies show that microendoscopic images can be interpreted visually to identify the presence of neoplasia in patients with Barrett's esophagus (BE), but this approach is subjective and requires clinical expertise. This study describes an approach for quantitative image analysis of microendoscopic images to identify neoplastic lesions in patients with BE.

METHODS

Images were acquired from 230 sites from 58 patients by using a fiberoptic high-resolution microendoscope during standard endoscopic procedures. Images were analyzed by a fully automated image processing algorithm, which automatically selected a region of interest and calculated quantitative image features. Image features were used to develop an algorithm to identify the presence of neoplasia; results were compared with a histopathology diagnosis.

RESULTS

A sequential classification algorithm that used image features related to glandular and cellular morphology resulted in a sensitivity of 84% and a specificity of 85%. Applying the algorithm to an independent validation set resulted in a sensitivity of 88% and a specificity of 85%.

CONCLUSIONS

This pilot study demonstrates that automated analysis of microendoscopic images can provide an objective, quantitative framework to assist clinicians in evaluating esophageal lesions from patients with BE. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01384227 and NCT02018367.).

ACG Clinical Guideline: Diagnosis and Management of Barrett's Esophagus

Barrett's esophagus (BE) is among the most common conditions encountered by the gastroenterologist. In this document, the American College of Gastroenterology updates its guidance for the best practices in caring for these patients. These guidelines continue to endorse screening of high-risk patients for BE; however, routine screening is limited to men with reflux symptoms and multiple other risk factors. Acknowledging recent data on the low risk of malignant progression in patients with nondysplastic BE, endoscopic surveillance intervals are attenuated in this population; patients with nondysplastic BE should undergo endoscopic surveillance no more frequently than every 3-5 years. Neither routine use of biomarker panels nor advanced endoscopic imaging techniques (beyond high-definition endoscopy) is recommended at this time. Endoscopic ablative therapy is recommended for patients with BE and high-grade dysplasia, as well as T1a esophageal adenocarcinoma. Based on recent level 1 evidence, endoscopic ablative therapy is also recommended for patients with BE and low-grade dysplasia, although endoscopic surveillance continues to be an acceptable alternative. Given the relatively common recurrence of BE after ablation, we suggest postablation endoscopic surveillance intervals. Although many of the recommendations provided are based on weak evidence or expert opinion, this document provides a pragmatic framework for the care of the patient with BE.

Prevention strategies for esophageal cancer: Perspectives of the East vs. West

Esophageal cancer is the eighth most common cancer worldwide. Esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC) are the two major phenotypes in Western and Eastern countries, respectively. Because of different pathways in carcinogenesis, the risk factors and effective steps for prevention of esophageal cancer are different between EAC and ESCC. The carcinogenesis of EAC is initiated by the acid exposure of the esophageal mucosa from stomach while that of the ESCC are related to the chronic irritation of carcinogens mainly by the alcohol, cigarette, betel quid, and hot beverage. To eliminate the burden of esophageal cancer on the global health, the effective strategy should be composed of the primary, secondary, and tertiary prevention. In this article, we perform a systematic review of the preventive strategies for esophageal cancer with special emphasis on the differences from the perspectives of Western and Eastern countries.

Spatial predisposition of dysplasia in Barrett's esophagus segments: a pooled analysis of the SURF and AIM dysplasia trials

OBJECTIVES

Surveillance endoscopy detects dysplasia within Barrett's esophagus (BE) and dictates treatment. Current biopsy regimens recommend uniformly spaced random biopsies. We assessed the distribution of dysplasia in BE to develop evidence-based biopsy regimens.

METHODS

We performed analysis of the distribution of dysplasia within BE using pretreatment biopsy data from two randomized controlled trials (RCTs) of radiofrequency ablation for dysplastic BE: the SURF (Surveillance vs. Radiofrequency Ablation) trial and the AIM Dysplasia (Ablation of Intestinal Metaplasia (AIM) Containing Dysplasia) trial. We used generalized linear models with generalized estimating equations (GEE) to estimate prevalence differences for dysplasia depending on the standardized location of biopsies. We performed Monte Carlo simulation of biopsy regimens to estimate their yield for any dysplasia within segments.

RESULTS

Dysplasia preferentially resides in the proximal-most half of the BE segment that is almost twice as likely to demonstrate dysplasia as the distal-most quartile. In pooled analysis, compared with the distal-most quarter, the prevalence difference in the proximal-most quarter was 22.6%, in the second proximal-most quarter 23.1%, and in the second distal-most quarter 15.3%. The best performing biopsy regimen in simulation studies acquired 8 biopsies in the most proximal cm of BE, 8 biopsies in the second cm, and 2 biopsies in each cm thereafter (q1cm: 8, 8, 2, 2…). A slightly simpler q2cm (every 2 cm) regimen (q2cm: 12, 12, 4…) was nearly as effective.

CONCLUSIONS

The post hoc analysis of two RCTs reveals a substantially increased prevalence of dysplasia proximally in BE segments. Our simulations suggest an altered biopsy regimen could increase sensitivity of biopsies in short-segment BE by >30%.

Detection and characterization of early malignancy in the esophagus: what is the best management algorithm?

Barrett's esophagus is a known precursor for esophageal adenocarcinoma. Early detection of dysplasia provides a window of opportunity for curative intervention. Several image-enhanced technologies have been developed to improve visualization of neoplasia. These however have not been found to be superior to the standard four quadrant random biopsy protocol. Patients are risk-stratified based on the degree of dysplasia found on biopsies and undergo either surveillance or treatment. Endoscopic therapy has become the mainstay of treatment for early neoplasia.

Improvement over time in outcomes for patients undergoing endoscopic therapy for Barrett's oesophagus-related neoplasia: 6-year experience from the first 500 patients treated in the UK patient registry

BACKGROUND

Barrett's oesophagus (BE) is a pre-malignant condition leading to oesophageal adenocarcinoma (OAC). Treatment of neoplasia at an early stage is desirable. Combined endoscopic mucosal resection (EMR) followed by radiofrequency ablation (RFA) is an alternative to surgery for patients with BE-related neoplasia.

METHODS

We examined prospective data from the UK registry of patients undergoing RFA/EMR for BE-related neoplasia from 2008 to 2013. Before RFA, visible lesions were removed by EMR. Thereafter, patients had RFA 3-monthly until all BE was ablated or cancer developed (endpoints). End of treatment biopsies were recommended at around 12 months from first RFA treatment or when endpoints were reached. Outcomes for clearance of dysplasia (CR-D) and BE (CR-IM) at end of treatment were assessed over two time periods (2008-2010 and 2011-2013). Durability of successful treatment and progression to OAC were also evaluated.

RESULTS

508 patients have completed treatment. CR-D and CR-IM improved significantly between the former and later time periods, from 77% and 56% to 92% and 83%, respectively (p<0.0001). EMR for visible lesions prior to RFA increased from 48% to 60% (p=0.013). Rescue EMR after RFA decreased from 13% to 2% (p<0.0001). Progression to OAC at 12 months is not significantly different (3.6% vs 2.1%, p=0.51).

CONCLUSIONS

Clinical outcomes for BE neoplasia have improved significantly over the past 6 years with improved lesion recognition and aggressive resection of visible lesions before RFA. Despite advances in technique, the rate of cancer progression remains 2-4% at 1 year in these high-risk patients.

TRIAL REGISTRATION NUMBER

ISRCTN93069556.

Effectiveness of focal vs. balloon radiofrequency ablation devices in the treatment of Barrett's esophagus

BACKGROUND AND AIMS

The safety and efficacy of radiofrequency ablation (RFA) in treatment of Barrett's esophagus (BE)-associated dysplasia has been well established. The effectiveness of focal and balloon RFA devices has not been compared. Therefore, the aim of our study was to assess the effectiveness of focal and balloon RFA devices in the treatment of BE by calculating absolute and percentage change in BE length with RFA therapy by comparing pre- and post-treatment BE length.

PATIENTS AND METHODS

This is a retrospective cross-sectional study of patients who underwent at least one treatment with either focal and/or balloon RFA devices who were identified from two tertiary centers. Patients' demographics, hiatal hernia, pre- and post-treatment BE length, prior use of endoscopic therapies and number of sessions were recorded.

RESULTS

Sixty-one patients who had undergone 161 RFA treatment sessions met inclusion criteria. There was no significant difference in percentage change in BE length with greater number of RFA sessions. RFA with a focal device resulted in greater percentage reduction in BE length compared to the balloon system (73% vs. 39%, p < 0.01). After adjusting for initial BE length, pre-treatment BE length, hernia status, prior endoscopic mucosal resection (EMR), prior RFA, and prior EMR/RFA sessions, RFA with a focal device at each session remained an independent predictor for a significant reduction in BE extent as compared to the balloon system.

CONCLUSION

The focal RFA device alone was more effective in treatment of BE compared to the balloon system, with a greater reduction in extent of BE. The focal RFA device for endoscopic eradication therapy of BE should be considered the preferred technique.

A Multiscale Model Evaluates Screening for Neoplasia in Barrett's Esophagus

Barrett’s esophagus (BE) patients are routinely screened for high grade dysplasia (HGD) and esophageal adenocarcinoma (EAC) through endoscopic screening, during which multiple esophageal tissue samples are removed for histological analysis. We propose a computational method called the multistage clonal expansion for EAC (MSCE-EAC) screening model that is used for screening BE patients in silico to evaluate the effects of biopsy sampling, diagnostic sensitivity, and treatment on disease burden. Our framework seamlessly integrates relevant cell-level processes during EAC development with a spatial screening process to provide a clinically relevant model for detecting dysplastic and malignant clones within the crypt-structured BE tissue. With this computational approach, we retain spatio-temporal information about small, unobserved tissue lesions in BE that may remain undetected during biopsy-based screening but could be detected with high-resolution imaging. This allows evaluation of the efficacy and sensitivity of current screening protocols to detect neoplasia (dysplasia and early preclinical EAC) in the esophageal lining. We demonstrate the clinical utility of this model by predicting three important clinical outcomes: (1) the probability that small cancers are missed during biopsy-based screening, (2) the potential gains in neoplasia detection probabilities if screening occurred via high-resolution tomographic imaging, and (3) the efficacy of ablative treatments that result in the curative depletion of metaplastic and neoplastic cell populations in BE in terms of the long-term impact on reducing EAC incidence.

Endoscopic screening for detecting cancer and cancer precursors in Barrett’s esophagus (BE) is currently informed by repeated systematic biopsying of the metaplastic BE tissue. Here we present a comprehensive multiscale model of the natural history of esophageal adenocarcinoma (EAC), which describes the entire multistage process beginning with the conversion event of normal squamous esophageal tissue to BE metaplasia, the spatio-temporal formation of independent dysplastic and malignant clones at the cell level, and finally the appearance of symptomatic EAC in BE. This model lends itself to a systematic exploration of the efficacy and sensitivity of current biopsy-based screening methods to detect neoplasia in BE patients, as well as alternative screening techniques based on high-resolution imaging of the BE tissue. Moreover, the model can also be used to predict the impact of ablative treatments on the risk of occurrence or recurrence of dysplasia or cancer. Due to the lack of studies that attempt to explicitly model the physical and biological dimensions of the screening process itself, our computational model provides a unique, publicly-available tool to improve understanding of factors that limit the efficacy of current screening protocols for BE patients.

Australian clinical practice guidelines for the diagnosis and management of Barrett's esophagus and early esophageal adenocarcinoma

Barrett's esophagus (BE), a common condition, is the only known precursor to esophageal adenocarcinoma (EAC). There is uncertainty about the best way to manage BE as most people with BE never develop EAC and most patients diagnosed with EAC have no preceding diagnosis of BE. Moreover, there have been recent advances in knowledge and practice about the management of BE and early EAC. To aid clinical decision making in this rapidly moving field, Cancer Council Australia convened an expert working party to identify pertinent clinical questions. The questions covered a wide range of topics including endoscopic and histological definitions of BE and early EAC; prevalence, incidence, natural history, and risk factors for BE; and methods for managing BE and early EAC. The latter considered modification of lifestyle factors; screening and surveillance strategies; and medical, endoscopic, and surgical interventions. To answer each question, the working party systematically reviewed the literature and developed a set of recommendations through consensus. Evidence underpinning each recommendation was rated according to quality and applicability.

Multiband mucosectomy for advanced dysplastic lesions in the upper digestive tract

Endoscopic resection (ER) is at present an accepted treatment for superficial gastrointestinal neoplasia. ER provides similar efficacy to surgery; however, it is minimally invasive and less expensive. Endoscopic mucosal resection (EMR) is superior to biopsy for diagnosing advanced dysplasia and can change the diagnostic grade and the management. Several EMR techniques have been described that are alternatively used dependent upon the endoscopist personal experience, the anatomic conditions and the endoscopic appearance of the lesion to be resected. The literature suggests that EMR offers comparable outcomes to surgery for selected indications. EMR techniques using a cap fitted endoscope and EMR using a ligation device [multiband mucosectomy (MBM)] are the most frequently use. MBM technique does not require submucosal injection as with the endoscopic resection-cap technique, multiple resections can be performed with the same snare, pre-looping the endoscopic resection-snare in the ridge of the cap is not necessary, MBM does not require withdrawal of the endoscope between resections and up to six consecutive resections can be performed. This reduces the time and cost required for the procedure, while also reducing patient discomfort. Despite the increasing popularity of MBM, data on the safety and efficacy of this technique in upper gastrointestinal lesions with advanced dysplasia, defined as those lesions that have high-grade dysplasia or early cancer, is limited.

Progression of esophageal dysplasia to cancer

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the evolution of low-grade squamous and glandular dysplasia to invasive carcinoma; the mutational spectra of Barrett's esophagus and adenocarcinoma; the risk of p53-immunoreactive glandular dysplasia compared to non-immunoreactive mucosa for progression to cancer; the role of lectins in progression to adenocarcinoma; and the role of racemase immunoreactivity in the prediction of risk of adenocarcinoma.

Smoking as an independent determinant of Barrett's esophagus and, to a lesser degree, of reflux esophagitis

PURPOSE

To evaluate the role of smoking in Barrett's esophagus (BE) and erosive esophagitis (E) compared to endoscopic controls with no BE or E. Smoking is considered a cause of both BE and E, but results on this topic are quite controversial.

METHODS

Patients with BE (339), E (462) and controls (619: 280 with GERD (gastroesophageal reflux disease)-negative and 339 with GERD-positive anamnesis) were recruited in 12 Italian endoscopy units. Data were obtained from structured questionnaires.

RESULTS

Among former smokers, a remarkable upward linear trend was found in BE for all smoking-related predictors. In particular, having smoked for more than 32 years increased the risk more than two times (OR 2.44, 95 % CL 1.33-4.45). When the analysis was performed in the subgroup of subjects with GERD-negative anamnesis, the risk of late quitters (<9 years) passed from OR 2.11 (95 % CL 1.19-3.72) to OR 4.42 (95 % CL 1.52-12.8). A noticeably positive dose-response relationship with duration was seen also among current smokers. As regards E, no straightforward evidence of association was detected, but for an increased risk of late quitters (OR 1.84, 95 % CL 1.14-2.98) in former smokers and for early age at starting (OR 3.63, 95 % CL 1.19-11.1) in GERD-negative current smokers.

CONCLUSIONS

Smoking seems to be an independent determinant of BE and, to a lesser degree, of E. The elevation in risk is independent from GERD and is already present in light cigarette smokers. Smoking cessation may reduce, but not remove this risk.

Utility of liquid-based cytologic examination of distal esophageal brushings in the management of Barrett esophagus: a prospective study of 45 cases

INTRODUCTION

The goal of Barrett esophagus surveillance is to identify high-grade dysplasia (HGD) for eradication. Surveillance programs currently rely on limited histologic sampling; however, the role of cytology in this setting is not well studied.

MATERIALS AND METHODS

From December 1, 2011 to March 30, 2014, 45 patients underwent 4 circumferential brushings of the distal tubular esophagus followed by standard 4-quadrant biopsies. One ThinPrep slide and 1 Cellient cellblock (Hologic, Boxborough, Mass) were prepared. Six cytopathologists evaluated each for adequacy, intestinal metaplasia (IM) and dysplasia. Findings were classified using the traditional 5-tier system used for biopsies. A prospectively modified 3-tier cytologic classification was also tested: negative for HGD, indeterminate for HGD, and HGD. Sensitivity, specificity, and kappa values (interobserver agreement) for cytology were calculated.

RESULTS

Ten of 45 patients had nondiagnostic cytologies; none of whom had dysplasia on biopsy. Cytology had good sensitivity (82%) and specificity (88%) for identifying IM compared with biopsy with moderate interobserver agreement (pairwise average of Fleiss and Krippendorf kappa value = 0.589, 79% agreement). One case had IM on cytology not detected on histology. Six of 45 patients had dysplasia on biopsy including 1 intramucosal adenocarcinoma, 1 indeterminate for dysplasia, 2 high-grade dysplasias, and 2 low-grade dysplasias. A non-negative adequate cytology sample had a sensitivity of 100% and a specificity of 88% and 94% for the 5-tier and the 3-tier classification, respectively.

CONCLUSIONS

Cytology appears to have good sensitivity and specificity for diagnosis of HGD, and cytology may be poised to synergize with advances in other techniques for management of patients with Barrett esophagus. Improvements in brushing devices may help to decrease the nondiagnostic rate.

Aberrant TP53 detected by combining immunohistochemistry and DNA-FISH improves Barrett's esophagus progression prediction: a prospective follow-up study

Barrett's esophagus (BE) goes through a sequence of low grade dysplasia (LGD) and high grade dysplasia (HGD) to esophageal adenocarcinoma (EAC). The current gold standard for BE outcome prediction, histopathological staging, can be unreliable. TP53 abnormalities may serve as prognostic biomarkers. TP53 protein accumulation detected by immunohistochemistry (IHC) indirectly assesses TP53 mutations. DNA fluorescent in situ hybridization (FISH) on brush cytology specimens directly evaluates gene locus loss. We evaluated if IHC and FISH are complementary tools to assess TP53 abnormalities and tested their prognostic value in a long-term prospective follow-up of a BE cohort. TP53 IHC on tissue sections and FISH on brush cytology specimens were evaluated for 116 BE patients with respect to the different histological stages. The TP53 abnormalities were further studied in a panel of cell lines representative of the Barrett's carcinogenic sequence. For 91patients, the predictive value of TP53 abnormalities with respect to progression to HGD/EAC was tested after long term follow-up. The frequency of IHC and FISH TP53 abnormalities increased significantly with increasing histological stage (P < 0.001, Chi(2) -test). Combining the techniques detected TP53 abnormalities in 100% of patients with LGD, HGD, and EAC. Multivariate analysis showed that IHC (hazard ratio: 17, 95% CI: 3.2-96, P = 0.001) and FISH (hazard ratio: 7.3, 95% CI: 1.3-41, P = 0.02) were both independent significant predictors of progression. Combining FISH and IHC in assessing TP53 abnormalities leads to an increased detection rate of TP53 aberrations and improved accuracy for predicting BE progression.

Long-term follow-up in patients with indeterminate Barrett esophagus

BACKGROUND

Barrett esophagus (BE) is a major risk factor for adenocarcinoma of the distal esophagus. Reliable detection of BE during upper endoscopy is therefore mandatory. According to most guidelines, diagnosis of BE requires both endoscopy and histology for confirmation. However, since adenocarcinomas were also described in patients with indeterminate BE, i.e. endoscopic visible columnar metaplasia but no histological confirmation of goblet cells or vice versa, debate has risen on the risk of malignancy and the need for endoscopic surveillance in such patients.

PATIENTS AND METHODS

The study was aimed to assess long-term follow-up data on 209 patients with indeterminate BE (on histopathology or endoscopy) initially examined between 1999 and 2000. Patients or referring physicians were contacted concerning the most recent endoscopic and histopathological results.

RESULTS

Follow-up data could be assessed in 149/209 patients (65.1%) after a mean follow-up period of 9.4 years (SD ±2.4 years). Neoplasia was not reported for any patient. The previous endoscopic-histopathological diagnoses could be confirmed in 3 patients only. In the group with endoscopic diagnosis of BE but no histopathological confirmation, BE was described histopathologically in 1 patient during follow-up.

CONCLUSION

Persistence of indeterminate BE is poor during long-term follow up. The risk of cancer appears to be negligible. Hence, surveillance of these patients appears equivocal.

Ablative therapy for esophageal dysplasia and early malignancy: focus on RFA

Ablative therapies have been utilized with increasing frequency for the treatment of Barrett's esophagus with and without dysplasia. Multiple modalities are available for topical ablation of the esophagus, but radiofrequency ablation (RFA) remains the most commonly used. There have been significant advances in technique since the introduction of RFA. The aim of this paper is to review the indications, techniques, outcomes, and most common complications following esophageal ablation with RFA.

Barrett's Esophagus

OPINION STATEMENT

Barrett's esophagus (BE) is the most important and recognizable precursor lesion for esophageal adenocarcinoma (EAC), which is the one of the fastest-growing cancers in the Western world (600 % in the U.S. in the last 40 years), and therefore it is critical to manage the risk of cancer present in BE. New developments in imaging and molecular markers, as well as an armamentarium of novel and effective endoscopic eradication therapy - especially radio-frequency ablation (RFA) and endoscopic mucosal resection (EMR) - are now available to the interventional endoscopist to help curb the significant rise of esophageal adenocarcinoma (EAC). Endoscopic surveillance is currently recommended by most gastroenterology societies worldwide, although there is no data to support this practice in relation to reducing mortality from EAC. Paradoxically, the cancer risk in Barrett's esophagus is being progressively downgraded, which raises fundamental questions about our understanding of the risk factors and molecular biology of the Barrett's metaplasia-dysplasia-adenocarcinoma sequence. The recent discovery of a strong association of transcriptionally active high-risk human papillomavirus (hr-HPV) with Barrett's dysplasia (BD) and EAC may shed some light on this anomaly. It is imperative that we identify the high-risk group of progressors to EAC. While p53 immunohistochemistry is currently probably the best clinical molecular marker for predicting disease progression in BD, we must think outside the box and cast the net wide in search of additional biomarkers (e.g., high-risk human papilloma virus (hr-HPV)].

Lissajous fiber scanning for forward viewing optical endomicroscopy using asymmetric stiffness modulation

We report a fully packaged and compact forward viewing endomicroscope by using a resonant fiber scanner with two dimensional Lissajous trajectories. The fiber scanner comprises a single mode fiber with additional microstructures mounted inside a piezoelectric tube with quartered electrodes. The mechanical cross-coupling between the transverse axes of a resonant fiber with a circular cross-section was completely eliminated by asymmetrically modulating the stiffness of the fiber cantilever with silicon microstructures and an off-set fiber fragment. The Lissajous fiber scanner was fully packaged as endomicroscopic catheter passing through the accessory channel of a clinical endoscope and combined with spectral domain optical coherence tomography (SD-OCT). Ex-vivo 3D OCT images were successfully reconstructed along Lissajous trajectory. The preview imaging capability of the Lissajous scanning enables rapid 3D imaging with high temporal resolution. This endoscopic catheter provides many opportunities for on-demand and non-invasive optical biopsy inside a gastrointestinal endoscope.

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.

I-SCAN targeted versus random biopsies in Barrett's oesophagus

BACKGROUND

The accuracy and effectiveness of targeted oesophageal biopsies in Barrett's oesophagus to detect dysplasia using new magnification techniques are unknown. Aim of this study was to investigate whether the combined use of acetic acid, magnification and electronic filters allows the same accuracy as the four-quadrant random biopsies pattern; pathologist interobserver agreement both in low grade and high grade dysplasia was also assessed.

METHODS

Fifty-four consecutive patients newly diagnosed with Barrett's oesophagus were enrolled in a prospective study from a single endoscopy unit. Biopsies were evaluated by the local pathologist and by an expert pathologist from another pathology unit.

MAIN OUTCOME MEASUREMENT

Dysplasia detection rate and interobserver agreement for the histologic diagnosis of dysplasia.

RESULTS

The use of acetic acid, magnification and electronic filters showed an unacceptably low dysplasia detection rate by the two pathologists (9.2% and 5.5% for targeted biopsies, respectively). The interobserver agreement for low grade dysplasia between pathologists was low (Cohen's K weighted=0.45).

CONCLUSIONS

In an average setting, the standard four-quadrant method should still be preferred, along with the implementation of a routine second evaluation by an expert pathologist.

Temporal and spatial evolution of somatic chromosomal alterations: a case-cohort study of Barrett's esophagus

All cancers are believed to arise by dynamic, stochastic somatic genomic evolution with genome instability, generation of diversity, and selection of genomic alterations that underlie multistage progression to cancer. Advanced esophageal adenocarcinomas have high levels of somatic copy number alterations. Barrett's esophagus is a risk factor for developing esophageal adenocarcinoma, and somatic chromosomal alterations (SCA) are known to occur in Barrett's esophagus. The vast majority (∼95%) of individuals with Barrett's esophagus do not progress to esophageal adenocarcinoma during their lifetimes, but a small subset develop esophageal adenocarcinoma, many of which arise rapidly even in carefully monitored patients without visible endoscopic abnormalities at the index endoscopy. Using a well-designed, longitudinal case-cohort study, we characterized SCA as assessed by single-nucleotide polymorphism arrays over space and time in 79 "progressors" with Barrett's esophagus as they approach the diagnosis of cancer and 169 "nonprogressors" with Barrett's esophagus who did not progress to esophageal adenocarcinoma over more than 20,425 person-months of follow-up. The genomes of nonprogressors typically had small localized deletions involving fragile sites and 9p loss/copy neutral LOH that generate little genetic diversity and remained relatively stable over prolonged follow-up. As progressors approach the diagnosis of cancer, their genomes developed chromosome instability with initial gains and losses, genomic diversity, and selection of SCAs followed by catastrophic genome doublings. Our results support a model of differential disease dynamics in which nonprogressor genomes largely remain stable over prolonged periods, whereas progressor genomes evolve significantly increased SCA and diversity within four years of esophageal adenocarcinoma diagnosis, suggesting a window of opportunity for early detection.

Magnifying endoscopy for the diagnosis of specialized intestinal metaplasia in short-segment Barrett’s esophagus

AIM: To determine whether magnified observation of short-segment Barrett’s esophagus (BE) is useful for the detection of specialized intestinal metaplasia (SIM).

METHODS: Thirty patients with suspected short-segment BE underwent magnifying endoscopy up to × 80. The magnified images were analyzed with respect to their pit-patterns, which were simultaneously classified into five epithelial types [I (small round), II (straight), III (long oval), IV (tubular), V (villous)] by Endo’s classification. Then, a 0.5% solution of methylene blue (MB) was sprayed over columnar mucosa. The patterns of the magnified image and MB staining were analyzed. Biopsies were obtained from the regions previously observed by magnifying endoscopy and MB chromoendoscopy.

RESULTS: Three of five patients with a type V (villous) epithelial pattern had SIM, whereas 21 patients with a non-type V epithelial patterns did not have SIM. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of pit-patterns in detecting SIM were 100%, 91.3%, 92.3%, 60% and 100%, respectively (P = 0.004). Three of the 12 patients with positive MB staining had SIM, whereas 14 patients with negative MB staining did not have SIM. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of MB staining in detecting SIM were 100%, 60.9%, 65.4%, 25% and 100%, respectively (P = 0.085). The specificity and accuracy of pit-pattern evaluation were significantly superior compared with MB staining for detecting SIM by comparison with the exact McNemar’s test (P = 0.0391).

CONCLUSION: The magnified observation of a short-segment BE according to the mucosal pattern and its classification can be predictive of SIM.

Association between obesity and Barrett's esophagus in a Japanese population: a hospital-based, cross-sectional study

Background

The association between obesity and Barrett’s esophagus (BE) in the Japanese population remains unclear. The prevalence of BE and its associated risk factors was examined.

Methods

A cross-sectional study of 1581 consecutive individuals who underwent upper gastrointestinal endoscopy was conducted. The prevalence of endoscopically suspected BE (ESBE) was evaluated. Obesity was evaluated by body mass index (BMI, ≥ 25 kg/m²) and waist circumference (WC) (males, ≥ 85 cm; females, ≥ 90 cm). Because endoscopic diagnosis of ultra-short ESBE (<1 cm in extent) is difficult and highly unreliable, this type of ESBE was excluded from the study.

Results

In proton pump inhibitor (PPI) non-users, the prevalence of ESBE ≥ 1 cm was 5.6%. In univariate analysis, male sex and reflux esophagitis (RE) were significantly associated with BE, but BMI, WC, and reflux symptoms were not. In multivariate logistic regression analysis, only RE (odds ratio [OR] = 3.48, 95% confidence interval [CI] 1.89-6.41, p < 0.0001) was an independent risk factor for BE; obesity and the other factors were not. In contrast, RE (OR 5.67, p = 0.0004) and large WC (OR 5.09, p = 0.0005) were significant risk factors for ESBE ≥ 1 cm in PPI users. Only male sex, but not obesity or the other risk factors, was associated with an increased risk of RE in patients not taking PPIs.

Conclusions

RE, but not obesity, may have an independent association with the risk of ESBE in the Japanese population. Furthermore, obesity measures were not independent risks for RE. Interestingly, PPI-refractory RE and large WC were risk factors for ESBE ≥1 cm in patients taking PPIs.

Radiofrequency ablation in the management of Barrett's esophagus: present role and future perspective

Esophageal adenocarcinoma is the most rapidly increasing gastrointestinal cancer. Barrett's esophagus has been identified as a precancerous condition and major risk factor for esophageal cancer. Radiofrequency ablation has been shown to be a highly efficient in promoting remission of intestinal metaplasia. This technology has seen widespread clinical use since 2005. Radiofrequency ablation is common with all other ablative techniques; the concern that sound oncological principles are not being adhered to, that is, appropriate pathological staging, followed by appropriate definitive therapy. Endoscopic mucosal excision techniques are technically demanding; however, they are more attractive from an oncological perspective. Future research endeavors focusing on facilitation of large population screening, the identification of high risk phenotypes, endoscopic mucosal resection techniques will combat the esophageal adenocarcinoma epidemic.

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.

Radiofrequency ablation and endoscopic mucosal resection for dysplastic barrett's esophagus and early esophageal adenocarcinoma: outcomes of the UK National Halo RFA Registry

BACKGROUND & AIMS

Patients with Barrett's esophagus (BE) and high-grade dysplasia (HGD) or early neoplasia increasingly receive endoscopic mucosal resection and radiofrequency ablation (RFA) therapy. We analyzed data from a UK registry that follows the outcomes of patients with BE who have undergone RFA for neoplasia.

METHODS

We collected data on 335 patients with BE and neoplasia (72% with HGD, 24% with intramucosal cancer, 4% with low-grade dysplasia [mean age, 69 years; 81% male]), treated at 19 centers in the United Kingdom from July 2008 through August 2012. Mean length of BE segments was 5.8 cm (range, 1-20 cm). Patients' nodules were removed by endoscopic mucosal resection, and the patients then underwent RFA every 3 months until all areas of BE were ablated or cancer developed. Biopsies were collected 12 months after the first RFA; clearance of HGD, dysplasia, and BE were assessed.

RESULTS

HGD was cleared from 86% of patients, all dysplasia from 81%, and BE from 62% at the 12-month time point, after a mean of 2.5 (range, 2-6) RFA procedures. Complete reversal dysplasia was 15% less likely for every 1-cm increment in BE length (odds ratio = 1.156; SE = 0.048; 95% confidence interval: 1.07-1.26; P < .001). Endoscopic mucosal resection before RFA did not provide any benefit. Invasive cancer developed in 10 patients (3%) by the 12-month time point and disease had progressed in 17 patients (5.1%) after a median follow-up time of 19 months. Symptomatic strictures developed in 9% of patients and were treated by endoscopic dilatation. Nineteen months after therapy began, 94% of patients remained clear of dysplasia.

CONCLUSIONS

We analyzed data from a large series of patients in the United Kingdom who underwent RFA for BE-related neoplasia and found that by 12 months after treatment, dysplasia was cleared from 81%. Shorter segments of BE respond better to RFA; http://www.controlled-trials.com, number ISRCTN93069556.

Endoscopic diagnosis of dysplasia in Barrett's esophagus

Barrett's esophagus, or columnar metaplasia with gastric cardiac cells or intestinal cells, develops in the squamous epithelium of the esophageal mucosa in relation to gastroesophageal reflux. An increased risk of neoplasia justifies surveillance at regular intervals. Conventional guidelines recommend detection of areas with intestinal metaplasia or dysplasia by taking random four-quadrant biopsies at every 1 or 2 cm. Alternatively, image processing with narrow band imaging (NBI), is proposed to improve detection. This international and randomized study in persons with Barrett's esophagus compares conventional endoscopy in white light with random four-quadrant biopsies and NBI imaging with focused biopsies only. Randomization enrolled 123 patients with Barrett's esophagus who successively underwent exploration with the two methods. The study confirmed that NBI had the same efficacy as white light in the detection of intestinal metaplasia, with a higher proportion of dysplasia detected (30 vs 21%) and a lower number of biopsies per patient (3.6 vs 7.6).

[Screening for adenocarcinoma in Barrett's esophagus: yes or no, when and how?]

Barrett's esophagus (BE) is the main recognized risk factor for the development of esophageal adenocarcinoma (EAC). The incidence of this cancer and its associated mortality has increased in developed countries during the last few years. Detection of EAC at earlier stages could potentially improve survival dramatically in these patients, which is especially important as mortality from EAC remains high despite the available treatments. Therefore, endoscopic surveillance is an attractive option for patients with Barrett's esophagus. Consequently, periodic endoscopic surveillance is recommended by all the International Gastroenterology Societies in an attempt to detect EAC at an early and potentially curable stage. Currently, the frequency of endoscopic surveillance and its need in Barrett's esophagus with low-grade dysplasia or without dysplasia are under discussion. This review presents the available evidence in order to assist clinicians in the decision-making process.

Management strategies of Barrett's esophagus

Barrett’s esophagus is a condition resulting from chronic gastro-esophageal reflux disease with a documented risk of esophageal adenocarcinoma. Current strategies for improved survival in patients with Barrett's adenocarcinoma focus on detection of dysplasia. This can be obtained by screening programs in high-risk cohorts of patients and/or endoscopic biopsy surveillance of patients with known Barrett’s esophagus (BE). Several therapies have been developed in attempts to reverse BE and reduce cancer risk. Aggressive medical management of acid reflux, lifestyle modifications, antireflux surgery, and endoscopic treatments have been recommended for many patients with BE. Whether these interventions are cost-effective or reduce mortality from esophageal cancer remains controversial. Current treatment requires combinations of endoscopic mucosal resection techniques to eliminate visible lesions followed by ablation of residual metaplastic tissue. Esophagectomy is currently indicated in multifocal high-grade neoplasia or mucosal Barrett’s carcinoma which cannot be managed by endoscopic approach.

Role of cytopathology in the diagnosis and management of gastrointestinal tract cancers

Cytology of gastro-intestinal (GI) tract lesions can be used successfully to diagnose neoplastic and non-neoplastic conditions, especially when combined with biopsies. Cytologic evaluation is widely accepted as a cost-effective method that allows rapid interpretation and triaging of material. Technical advances over the years have allowed simultaneous visualization of abnormal tissue and procurement of needle aspirates, brushings and biopsies from mucosal and deeper seated lesions. Successful cytologic examination of the GI tract is highly dependent on the skill of the endoscopist, specimen preparation, the expertise of the pathologist, and the recognition of the limitations of cytology. This article reviews the key cytologic features of important GI tract lesions, differential diagnoses, and pitfalls, and addresses the advantages and limitations of different collection techniques.

Management of Barrett's oesophagus and intramucosal oesophageal cancer: a review of recent development

Barrett's oesophagus is the most important and recognizable precursor lesion for oesophageal adenocarcinoma, which is the one of the fastest growing cancers in the Western World. The incidence of oesophageal adenocarcinoma has increased 600% in the United States between 1975 and 2001 and is thought to represent a real increase in burden rather than a result of histologic or anatomical misclassification or overdiagnosis. Thus, the cancer risk in Barrett's oesophagus has to be managed and involves prevention (surveillance endoscopy), treating underlying gastroesophageal reflux disease (medically and or surgically) and endoscopic therapy to remove diseased epithelium in appropriate patient subgroups. In the last decade, new developments in imaging and molecular markers as well as an armamentarium of novel and effective endoscopic eradication therapy has become available to the endoscopist to combat this exponential rise in oesophageal adenocarcinoma. Paradoxically, the cancer risk in Barrett's oesophagus gets progressively downgraded which raises fundamental questions about our understanding of the known and unknown risk factors and molecular aberrations that are involved in the Barrett's metaplasia-dysplasia-carcinoma sequence. Future research has to be directed at these areas to fine tune our screening and surveillance programs to identify more accurately the high-risk group of progressors to oesophageal adenocarcinoma who would benefit most from endoscopic therapy.

Activation of Wnt signalling promotes development of dysplasia in Barrett's oesophagus

Barrett's oesophagus is a precursor of oesophageal adenocarcinoma, via intestinal metaplasia and dysplasia. Risk of cancer increases substantially with dysplasia, particularly high-grade dysplasia. Thus, there is a clinical need to identify and treat patients with early-stage disease (metaplasia and low-grade dysplasia) that are at high risk of cancer. Activated Wnt signalling is critical for normal intestinal development and homeostasis, but less so for oesophageal development. Therefore, we asked whether abnormally increased Wnt signalling contributes to the development of Barrett's oesophagus (intestinal metaplasia) and/or dysplasia. Forty patients with Barrett's metaplasia, dysplasia or adenocarcinoma underwent endoscopy and biopsy. Mice with tamoxifen- and β-naphthoflavone-induced expression of activated β-catenin were used to up-regulate Wnt signalling in mouse oesophagus. Immunohistochemistry of β-catenin, Ki67, a panel of Wnt target genes, and markers of intestinal metaplasia was performed on human and mouse tissues. In human tissues, expression of nuclear activated β-catenin was found in dysplasia, particularly high grade. Barrett's metaplasia did not show high levels of activated β-catenin. Up-regulation of Ki67 and Wnt target genes was also mostly associated with high-grade dysplasia. Aberrant activation of Wnt signalling in mouse oesophagus caused marked tissue disorganization with features of dysplasia, but only selected molecular indicators of metaplasia. Based on these results in human tissues and a mouse model, we conclude that abnormal activation of Wnt signalling likely plays only a minor role in initiation of Barrett's metaplasia but a more critical role in progression to dysplasia.

Optical imaging modalities for biomedical applications

Optical photographic imaging is a well known imaging method that has been successfully translated into biomedical applications such as microscopy and endoscopy. Although several advanced medical imaging modalities are used today to acquire anatomical, physiological, metabolic, and functional information from the human body, optical imaging modalities including optical coherence tomography, confocal microscopy, multiphoton microscopy, multispectral endoscopy, and diffuse reflectance imaging have recently emerged with significant potential for non-invasive, portable, and cost-effective imaging for biomedical applications spanning tissue, cellular, and molecular levels. This paper reviews methods for modeling the propagation of light photons in a biological medium, as well as optical imaging from organ to cellular levels using visible and near-infrared wavelengths for biomedical and clinical applications.

The risk of lymph-node metastases in patients with high-grade dysplasia or intramucosal carcinoma in Barrett's esophagus: a systematic review

OBJECTIVES

Endoscopic eradication therapy is used to treat mucosal neoplasms in Barrett's esophagus, but cannot cure cancers that have metastasized to lymph nodes. The risk of such metastases has been proposed as a reason to consider esophagectomy rather than endoscopic therapy for esophageal mucosal neoplasia. The objective of our study was to determine the frequency of lymph-node metastases in patients with high-grade dysplasia (HGD) and intramucosal carcinoma in Barrett's esophagus.

METHODS

We performed a systematic review using the PRISMA guidelines to identify studies that included patients who had esophagectomy for HGD or intramucosal carcinoma in Barrett's esophagus, and that reported final pathology results after examination of esophagectomy specimens.

RESULTS

We identified 70 relevant reports that included 1,874 patients who had esophagectomy performed for HGD or intramucosal carcinoma in Barrett's esophagus. Lymph-node metastases were found in 26 patients (1.39 % , 95 % CI 0.86 – 1.92). No metastases were found in the 524 patients who had a final pathology diagnosis of HGD, whereas 26 (1.93 % , 95 % CI 1.19 – 2.66 %) of the 1,350 patients with a final pathology diagnosis of intramucosal carcinoma had positive lymph nodes.

CONCLUSIONS

The risk of unexpected lymph-node metastases for patients with mucosal neoplasms in Barrett's esophagus is in the range of 1 – 2 %. Esophagectomy has a mortality rate that often exceeds 2 %, with substantial morbidity and no guarantee of curing metastatic disease. Therefore, the risk of lymph node metastases alone does not warrant the choice of esophagectomy over endoscopic therapy for HGD and intramucosal carcinoma in Barrett's esophagus.

Advanced endoscopic imaging in Barrett's oesophagus

Barrett's oesophagus is a metaplastic condition with an inherent risk of progression to adenocarcinoma. It is essential to identify dysplastic changes within Barrett's oesophagus in order to individualise surveillance strategies and establish which patients warrant endoscopic treatment. There is a trend towards endoscopic resection of focal high-grade dysplasia followed by whole segment ablation. However, endoscopic identification of dysplastic lesions is unreliable and subjective making targeted therapy extremely difficult. In addition, the current practice of taking random quadrantic biopsies may miss dysplastic disease and intramucosal adenocarcinoma. Several advanced endoscopic imaging techniques have been described and tested in clinical trials in an effort to improve the detection of early lesions, although none are routinely used in clinical practice. In this article we will review these techniques and discuss their potential for clinical implementation. We will also discuss the potential benefits of multimodal imaging and highlight several newer techniques which have shown early promise for in vivo diagnosis.

Endoscopic therapy for Barrett's esophagus: a review of its emerging role in optimal diagnosis and endoluminal therapy

Barrett's esophagus (BE) is a premalignant lesion known to sequentially progress to esophageal adenocarcinoma. Management of BE has changed significantly over the last 5 years with the development of endoscopic resection and ablation, which has replaced esophagectomy as the treatment of choice in BE with high-grade dysplasia. The aim of this review is to discuss the details of these new endotherapies in regards to response and durability and to define the role of these new therapies in the current management of BE.

History of cancer in first degree relatives of Barrett's esophagus patients: a case-control study

BACKGROUND AND OBJECTIVE

Familial clusters of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) have been reported. This study evaluates the history of cancer in BE patients families.

METHODS

In two years, patients with BE (272), esophagitis (456) and controls (517) were recruited in 12 Italian Endoscopy Units. Cancer family history in first-degree (FD) relatives was determined by a questionnaire.

RESULTS

Approximately 53% of BE, 51% of esophagitis, and 48% of controls had at least one relative affected by any type of malignancy. Probands with at least one esophageal or gastric (E/G) cancer-affected relative showed a BE risk which was at least eighty-five percent higher than that of probands without affected relatives. The relative risk of BE was 4.18, 95% CL=0.76-23.04 if a FD relative had early (mean age ≤ 50 years) onset E/G cancer compared to late onset E/G cancer.

CONCLUSION

In this sample there was no evidence that a family history of cancer was associated with the diagnosis of BE. An intriguing result was the association between the occurrence of E/G cancers at earlier ages (< 50 years) among BE relatives with respect the control group. This could suggest a genetic contribution in onset of these tumors, but the sample was too small to demonstrate a significant association. Further exploration of family history of E/G cancer and a diagnosis of BE in larger samples is warranted.

Novel probe-based confocal laser endomicroscopy criteria and interobserver agreement for the detection of dysplasia in Barrett's esophagus

OBJECTIVES

Probe-based confocal laser endomicroscopy (pCLE) is an imaging technique that allows real-time in vivo histological assessment of Barrett's esophagus (BE). The objectives of this study were to create and test novel pCLE criteria for dysplastic BE (phase I), and to evaluate accuracy, interobserver variability, and learning curve in dysplasia prediction (phase II) using these criteria.

METHODS

In phase I, using 50 pCLE videos, a pCLE expert and gastrointestinal pathologist formulated new BE criteria by consensus. These criteria were tested and refined in an independent set of 30 pCLE videos. In phase II, a formal training session for all assessors (three each experts/trainees) was conducted. Finally, using 75 testing videos, each video was interpreted as dysplasia (high-grade dysplasia (HGD)/cancer) vs. no dysplasia and the assessors' confidence in interpretation was noted. Interobserver agreement and accuracy (95% confidence interval (CI)) were determined for BE histology prediction.

RESULTS

Of multiple pCLE criteria tested (phase I), only those with ≥70% sensitivity or specificity were included in the final set: epithelial surface: saw-toothed; cells: enlarged; cells: pleomorphic; glands: not equidistant; glands: unequal in size and shape; goblet cells: not easily identified. Overall accuracy in diagnosing dysplasia was 81.5% (95% CI: 77.5-81), with no difference between experts vs. non-experts. Accuracy of prediction was significantly higher when endoscopists were "confident" about their diagnosis (98% (95-99) vs. 62% (54-70), P<0.001). Accuracy of dysplasia prediction for the first 30 videos was not different from the last 45 (93 vs. 81%, P=0.51). Overall agreement of the criteria was substantial, κ=0.61 (0.53-0.69), with no difference between experts and non-experts.

CONCLUSIONS

We demonstrate the development and validation of new pCLE criteria for the prediction of HGD/cancer in BE patients. Using these criteria, this study demonstrated that overall accuracy in predicting dysplasia was high with substantial interobserver agreement. After a structured teaching session, accuracy and agreement between experienced and non-experienced observers was not different, suggesting a short learning curve.

Gastroesophageal reflux disease symptom severity, proton pump inhibitor use, and esophageal carcinogenesis

HYPOTHESIS

Screening for esophageal adenocarcinoma has focused on identifying Barrett esophagus (BE) in patients with severe, long-standing symptoms of gastroesophageal reflux disease (GERD). Unfortunately, 95% of patients who develop esophageal adenocarcinoma are unaware of the presence of BE before their cancer diagnosis, which means they never had been selected for screening. One possible explanation is that no correlation exists between the severity of GERD symptoms and cancer risk. We hypothesize that severe GERD symptoms are not associated with an increase in the prevalence of BE, dysplasia, or cancer in patients undergoing primary endoscopic screening.

DESIGN

Cross-sectional study.

SETTING

University hospital.

PATIENTS

A total of 769 patients with GERD.

INTERVENTIONS

Primary screening endoscopy performed from November 1, 2004, through June 7, 2007.

MAIN OUTCOMES MEASURES

Symptom severity, proton pump inhibitor therapy, and esophageal adenocarcinogenesis (ie, BE, dysplasia, or cancer).

RESULTS

Endoscopy revealed adenocarcinogenesis in 122 patients. An increasing number of severe GERD symptoms correlated positively with endoscopic findings of esophagitis (odds ratio, 1.05; 95% confidence interval, 1.01-1.09). Conversely, an increasing number of severe GERD symptoms were associated with decreased odds of adenocarcinogenesis (odds ratio, 0.94; 95% confidence interval, 0.89-0.98). Patients taking proton pump inhibitors were 61.3% and 81.5% more likely to have adenocarcinogenesis if they reported no severe typical or atypical GERD symptoms, respectively, compared with patients taking proton pump inhibitors, who reported that all symptoms were severe.

CONCLUSIONS

Medically treated patients with mild or absent GERD symptoms have significantly higher odds of adenocarcinogenesis compared with medically treated patients with severe GERD symptoms. This finding may explain the failure of the current screening paradigm in which the threshold for primary endoscopic examination is based on symptom severity.

Management of cancer risk in Barrett's esophagus

The importance of Barrett's esophagus (BE) lies in its potential to give rise to esophageal adenocarcinoma (EAC), postulated to be through a series of progressive degrees of dysplasia; from intestinal metaplasia to low-grade dysplasia, high-grade dysplasia, and subsequently, to cancer. The management strategies for the detection and treatment of dysplasia and early esophageal cancer on a background of BE have changed significantly in the last few decades, with the emergence of newer and less invasive non-operative alternatives. This review aims to outline BE and its relation to EAC, the rationale and cost-effectiveness of both screening and surveillance programs, methods of diagnosing and identifying dysplasia and early cancer in Barrett's, and approaches to individualizing their endoscopic and surgical management based on best-available staging techniques.

Evaluation of difluoromethylornithine for the chemoprevention of Barrett's esophagus and mucosal dysplasia

Patients with Barrett's esophagus (BE) and dysplasia are candidates for chemopreventive strategies to reduce cancer risk. We determined the effects of difluoromethylornithine (DMFO) on mucosal polyamines, gene expression, and histopathology in BE. Ten patients with BE and low-grade dysplasia participated in a single-arm study of DFMO (0.5 g/m(2)/d) given continuously for 6 months. Esophagoscopy with biopsies was conducted at baseline, 3, 6, and 12 months. Dysplasia was graded by a gastrointestinal pathologist. Audiology was assessed (at baseline and at 6 months). Mucosal polyamines were measured by high-performance liquid chromatography. Microarray-based gene expression was analyzed using a cDNA two-color chip. DFMO suppressed levels of the polyamines putrescine (P = 0.02) and spermidine (P = 0.02) and the spermidine/spermine ratio (P < 0.01) in dysplastic BE (6 months vs. baseline) that persisted at 6 months following drug cessation. Among the top 25 modulated genes, we found those regulating p53-mediated cell signaling (RPL11), cell-cycle regulation (cyclin E2), and cell adhesion and invasion (Plexin1). DFMO downregulated Krüppel-like factor 5 (KLF5), a transcription factor promoting cell proliferation, and suppressed RFC5 whose protein interacts with proliferating cell nuclear antigen. Histopathology showed regression of dysplasia (n = 1), stable disease (n = 8), and progression to high-grade dysplasia (n = 1). Polyamines were suppressed in the responder to a greater extent than in stable cases. DFMO was well tolerated, and one patient had subclinical, unilateral ototoxicity. DFMO suppressed mucosal polyamines and modulated genes that may be mechanistically related to its chemopreventive effect. Further study of DFMO for the chemoprevention of esophageal cancer in BE patients is warranted.