Spatio-temporal classification for polyp diagnosis

Colonoscopy remains the gold standard investigation for colorectal cancer screening as it offers the opportunity to both detect and resect pre-cancerous polyps. Computer-aided polyp characterisation can determine which polyps need polypectomy and recent deep learning-based approaches have shown promising results as clinical decision support tools. Yet polyp appearance during a procedure can vary, making automatic predictions unstable. In this paper, we investigate the use of spatio-temporal information to improve the performance of lesions classification as adenoma or non-adenoma. Two methods are implemented showing an increase in performance and robustness during extensive experiments both on internal and openly available benchmark datasets.

Clonal Transitions and Phenotypic Evolution in Barrett's Esophagus

BACKGROUND & AIMS

Barrett's esophagus (BE) is a risk factor for esophageal adenocarcinoma but our understanding of how it evolves is poorly understood. We investigated BE gland phenotype distribution, the clonal nature of phenotypic change, and how phenotypic diversity plays a role in progression.

METHODS

Using immunohistochemistry and histology, we analyzed the distribution and the diversity of gland phenotype between and within biopsy specimens from patients with nondysplastic BE and those who had progressed to dysplasia or had developed postesophagectomy BE. Clonal relationships were determined by the presence of shared mutations between distinct gland types using laser capture microdissection sequencing of the mitochondrial genome.

RESULTS

We identified 5 different gland phenotypes in a cohort of 51 nondysplastic patients where biopsy specimens were taken at the same anatomic site (1.0-2.0 cm superior to the gastroesophageal junction. Here, we observed the same number of glands with 1 and 2 phenotypes, but 3 phenotypes were rare. We showed a common ancestor between parietal cell-containing, mature gastric (oxyntocardiac) and goblet cell-containing, intestinal (specialized) gland phenotypes. Similarly, we have shown a clonal relationship between cardiac-type glands and specialized and mature intestinal glands. Using the Shannon diversity index as a marker of gland diversity, we observed significantly increased phenotypic diversity in patients with BE adjacent to dysplasia and predysplasia compared to nondysplastic BE and postesophagectomy BE, suggesting that diversity develops over time.

CONCLUSIONS

We showed that the range of BE phenotypes represents an evolutionary process and that changes in gland diversity may play a role in progression. Furthermore, we showed a common ancestry between gastric and intestinal-type glands in BE.

Initial Responses to False Positives in AI-Supported Continuous Interactions: A Colonoscopy Case Study

The use of artificial intelligence (AI) in clinical support systems is increasing. In this article, we focus on AI support for continuous interaction scenarios. A thorough understanding of end-user behaviour during these continuous human-AI interactions, in which user input is sustained over time and during which AI suggestions can appear at any time, is still missing. We present a controlled lab study involving 21 endoscopists and an AI colonoscopy support system. Using a custom-developed application and an off-the-shelf videogame controller, we record participants’ navigation behaviour and clinical assessment across 14 endoscopic videos. Each video is manually annotated to mimic an AI recommendation, being either true positive or false positive in nature. We find that time between AI recommendation and clinical assessment is significantly longer for incorrect assessments. Further, the type of medical content displayed significantly affects decision time. Finally, we discover that the participant’s clinical role plays a large part in the perception of clinical AI support systems. Our study presents a realistic assessment of the effects of imperfect and continuous AI support in a clinical scenario.

Copper nanowire embedded hypromellose: An antibacterial nanocomposite film

The present work reports a novel antibacterial nanocomposite film comprising of copper nanowire impregnated biocompatible hypromellose using polyethylene glycol as a plasticiser. Detailed physico-chemical characterization using X-ray diffraction, Fourier transform infrared spectroscopy, UV-Visible spectroscopy and electron microscopy shows uniform dispersion of copper nanowire in the polymer matrix without any apparent oxidation. The film is flexible and shows excellent antibacterial activity against both Gram positive and negative bacteria at 4.8 wt% nanowire loading with MIC values of 400 μg/mL and 500 μg/mL for E. coli and S. aureus respectively. Investigation into the antibacterial mechanism of the composite indicates multiple pathways including cellular membrane damage caused by released copper ions and reactive oxygen species generation in the microbial cell. Interestingly, the film showed good biocompatibility towards normal human dermal fibroblast at minimum bactericidal concentration (MBC). Compared to copper nanoparticles as reported earlier in vitro studies, this low cytotoxicity of copper nanowires is due to the slow dissolution rate of the film and production of lower amount of ROS producing Cu²⁺ ions. Thus, the study indicates a strong potential for copper nanowire-based composites films in broader biomedical and clinical applications.

Utility and Cost-Effectiveness of a Nonendoscopic Approach to Barrett's Esophagus Surveillance After Endoscopic Therapy

BACKGROUND & AIMS

A non-endoscopic approach to Barrett's esophagus (BE) surveillance after radiofrequency ablation (RFA) would offer a less invasive method for monitoring. We assessed the test characteristics and cost-effectiveness of the Cytosponge (Medtronic, Minneapolis, MN) in post-RFA patients.

METHODS

We performed a multicenter study of dysplastic BE patients after at least one round of RFA. A positive Cytosponge before endoscopy was defined as intestinal metaplasia (IM) on cytological assessment and/or TFF3 immunohistochemistry. Sensitivity, specificity, and receiver operator characteristic (ROC) curves were calculated. Multivariable regression was used to estimate the odds of a positive Cytosponge in BE. A microsimulation cost-effectiveness model was performed to assess outcomes of various surveillance strategies: endoscopy-only, Cytosponge-only, and alternating endoscopy/Cytosponge.

RESULTS

Of 234 patients, Cytosponge adequately sampled the distal esophagus in 175 (75%). Of the 142 with both endoscopic and histologic data, 19 (13%) had residual/recurrent BE. For detecting any residual Barrett's, Cytosponge had a sensitivity of 74%, specificity of 85%, accuracy of 84%, and ROC curve showed an area under the curve of 0.74. The adjusted odds of a positive Cytosponge in BE were 17.1 (95% CI, 5.2-55.9). Cytosponge-only surveillance dominated all the surveillance strategies, being both less costly and more effective. Cytosponge-only surveillance required <1/4^th the endoscopies, resulting in only 0.69 additional EAC cases/1000 patients, and no increase in EAC deaths when compared to currently-practiced endoscopy-only surveillance.

CONCLUSIONS

A positive Cytosponge test was strongly associated with residual BE after ablation. While the assay needs further refinement in this context, it could serve as a cost-effective surveillance examination.

Accuracy of clinical staging for T2N0 oesophageal cancer: systematic review and meta-analysis

Oesophageal cancer is the sixth commonest cause of overall cancer mortality. Clinical staging utilizes multiple imaging modalities to guide treatment and prognostication. T2N0 oesophageal cancer is a treatment threshold for neoadjuvant therapy. Data on accuracy of current clinical staging tests for this disease subgroup are conflicting. We performed a meta-analysis of all primary studies comparing clinical staging accuracy using multiple imaging modalities (index test) to histopathological staging following oesophagectomy (reference standard) in T2N0 oesophageal cancer. Patients that underwent neoadjuvant therapy were excluded. Electronic databases (MEDLINE, Embase, Cochrane Library) were searched up to September 2019. The primary outcome was diagnostic accuracy of combined T&N clinical staging. Publication date, first recruitment date, number of centers, sample size and geographical location main histological subtype were evaluated as potential sources of heterogeneity. The search strategy identified 1,199 studies. Twenty studies containing 5,213 patients met the inclusion criteria. Combined T&N staging accuracy was 19% (95% CI, 15-24); T staging accuracy was 29% (95% CI, 24-35); percentage of patients with T downstaging was 41% (95% CI, 33-50); percentage of patients with T upstaging was 28% (95% CI, 24-32) and percentage of patients with N upstaging was 34% (95% CI, 30-39). Significant sources of heterogeneity included the number of centers, sample size and study region. T2N0 oesophageal cancer staging remains inaccurate. A significant proportion of patients were downstaged (could have received endotherapy) or upstaged (should have received neoadjuvant chemotherapy). These findings were largely unchanged over the past two decades highlighting an urgent need for more accurate staging tests for this subgroup of patients.

A clinically interpretable convolutional neural network for the real-time prediction of early squamous cell cancer of the esophagus: comparing diagnostic performance with a panel of expert European and Asian endoscopists

BACKGROUND AND AIMS

Intrapapillary capillary loops (IPCLs) are microvascular structures that correlate with the invasion depth of early squamous cell neoplasia and allow accurate prediction of histology. Artificial intelligence may improve human recognition of IPCL patterns and prediction of histology to allow prompt access to endoscopic therapy for early squamous cell neoplasia where appropriate.

METHODS

One hundred fifteen patients were recruited at 2 academic Taiwanese hospitals. Magnification endoscopy narrow-band imaging videos of squamous mucosa were labeled as dysplastic or normal according to their histology, and IPCL patterns were classified by consensus of 3 experienced clinicians. A convolutional neural network (CNN) was trained to classify IPCLs, using 67,742 high-quality magnification endoscopy narrow-band images by 5-fold cross validation. Performance measures were calculated to give an average F1 score, accuracy, sensitivity, and specificity. A panel of 5 Asian and 4 European experts predicted the histology of a random selection of 158 images using the Japanese Endoscopic Society IPCL classification; accuracy, sensitivity, specificity, positive and negative predictive values were calculated.

RESULTS

Expert European Union (EU) and Asian endoscopists attained F1 scores (a measure of binary classification accuracy) of 97.0% and 98%, respectively. Sensitivity and accuracy of the EU and Asian clinicians were 97%, 98% and 96.9%, 97.1%, respectively. The CNN average F1 score was 94%, sensitivity 93.7%, and accuracy 91.7%. Our CNN operates at video rate and generates class activation maps that can be used to visually validate CNN predictions.

CONCLUSIONS

We report a clinically interpretable CNN developed to predict histology based on IPCL patterns, in real time, using the largest reported dataset of images for this purpose. Our CNN achieved diagnostic performance comparable with an expert panel of endoscopists.

Cryoballoon ablation for treatment of patients with refractory esophageal neoplasia after first line endoscopic eradication therapy

Background and study aims  Cryoablation with the Cryoballoon device is a novel ablative therapy that uses cycles of freezing and thawing to induce cell death. This single-center prospective study evaluated the feasibility of the focal cryoablation device for the treatment of areas of refractory esophageal neoplasia in patients who had undergone first line endoscopic eradication therapy (EET). Complete remission of dysplasia (CR-D) and complete remission of intestinal metaplasia (CR-IM) at first follow-up endoscopy, durability of disease reversal, rates of stenosis and adverse events were studied. Patients and methods  Eighteen cases were treated. At baseline, nine patients had low-grade dysplasia (LGD), six had high-grade dysplasia (HGD) and three had intramucosal carcinoma (IMC). Median length of dysplastic Barrett's esophagus (BE) treated was 3 cm. The median number of ablations per patient was 11. Each selected area of visible dysplasia received 10 seconds of ablation. One session of cryoablation was performed per patient. Biopsies were performed at around 3 months post-ablation. Results  CR-D was achieved in 78 % and CR-IM in 39 % of patients. There were no device malfunction or adverse events. Stenosis was noted in 11 % of cases. At a median follow up of 19-months, CR-D was maintained in 72 % of patients and CR-IM in 33 %. Conclusions  Cryoablation appears to be a viable rescue strategy in patients with refractory neoplasia. It is well tolerated and successful in obtaining CR-D and CR-IM in patients with treatment-refractory BE. Further trials of dosimetry, efficacy and safety in treatment-naïve patients are underway.

The cost-effectiveness of radiofrequency ablation for treating patients with gastric antral vascular ectasia refractory to first line endoscopic therapy

Objective: This economic evaluation aims to provide a preliminary assessment of the cost-effectiveness of radiofrequency ablation (RFA) compared with argon plasma coagulation (APC) when used to treat APC-refractory gastric antral vascular ectasia (GAVE) in symptomatic patients.Methods: A Markov model was constructed to undertake a cost-utility analysis for adults with persistent symptoms secondary to GAVE refractory to first line endoscopic therapy. The economic evaluation was conducted from a UK NHS and personal social services (PSS) perspective, with a 20-year time horizon, comparing RFA with APC. Patients transfer between health states defined by haemoglobin level. The clinical effectiveness data were sourced from expert opinion, resource use and costs were reflective of the UK NHS and benefits were quantified using Quality Adjusted Life Years (QALYs) with utility weights taken from the literature. The primary output was the Incremental Cost-Effectiveness Ratio (ICER), expressed as cost per QALY gained.Results: Over a lifetime time horizon, the base case ICER was £4840 per QALY gained with an 82.2% chance that RFA was cost-effective at a threshold of £20,000 per QALY gained. The model estimated that implementing RFA would result in reductions in the need for intravenous iron, endoscopic intervention and requirement for blood transfusions by 27.1%, 32.3% and 36.5% respectively. Compared to APC, RFA was associated with an estimated 36.7% fewer procedures.Conclusions: RFA treatment is likely to be cost-effective for patients with ongoing symptoms following failure of first line therapy with APC and could lead to substantive reductions in health care resource.

Intrapapillary capillary loop classification in magnification endoscopy: open dataset and baseline methodology

PURPOSE

Early squamous cell neoplasia (ESCN) in the oesophagus is a highly treatable condition. Lesions confined to the mucosal layer can be curatively treated endoscopically. We build a computer-assisted detection system that can classify still images or video frames as normal or abnormal with high diagnostic accuracy.

METHODS

We present a new benchmark dataset containing 68K binary labelled frames extracted from 114 patient videos whose imaged areas have been resected and correlated to histopathology. Our novel convolutional network architecture solves the binary classification task and explains what features of the input domain drive the decision-making process of the network.

RESULTS

The proposed method achieved an average accuracy of 91.7% compared to the 94.7% achieved by a group of 12 senior clinicians. Our novel network architecture produces deeply supervised activation heatmaps that suggest the network is looking at intrapapillary capillary loop patterns when predicting abnormality.

CONCLUSION

We believe that this dataset and baseline method may serve as a reference for future benchmarks on both video frame classification and explainability in the context of ESCN detection. A future work path of high clinical relevance is the extension of the classification to ESCN types.

Outcomes from an international multicenter registry of patients with acute gastrointestinal bleeding undergoing endoscopic treatment with Hemospray

BACKGROUND AND AIM

Acute gastrointestinal bleeding carries poor outcomes unless prompt endoscopic hemostasis is achieved. Mortality in these patients remains significant. Hemospray is a novel intervention that creates a mechanical barrier over bleeding sites. We report the largest dataset of patient outcomes after treatment with Hemospray from an international multicenter registry.

PATIENTS AND METHODS

Prospective data (Jan 2016-May 2018) from 12 centers across Europe were collected. Immediate hemostasis was defined as endoscopic cessation of bleeding within 5 min after application of Hemospray. Rebleeding was defined as subsequent drop in hemoglobin, hematemesis, persistent melena with hemodynamic compromise post-therapy.

RESULTS

Three hundred and fourteen cases were recruited worldwide (231 males, 83 females). Median pretreatment Blatchford score was 11 (IQR: 8-14) and median complete Rockall score (RS) was 7 (IQR: 6-8) for all patients. Peptic ulcer disease (PUD) was the most common pathology (167/314 = 53%) and Forrest Ib the most common bleed type in PUD (100/167 = 60%). 281 patients (89.5%) achieved immediate hemostasis after successful endoscopic therapy with Hemospray. Rebleeding occurred in 29 (10.3%) of the 281 patients who achieved immediate hemostasis. Seven-day and 30-day all-cause mortality were 11.5% (36/314) and 20.1% (63/314), respectively (lower than the predicted rates as per the RS). Similar hemostasis rates were noted in the Hemospray monotherapy (92.4%), combination therapy (88.7%) and rescue therapy (85.5%) groups.

CONCLUSIONS

These data show high rates of immediate hemostasis overall and in all subgroups. Rebleeding and mortality rates were in keeping/lower than predicted rates.

Achalasia diagnosed despite normal integrated relaxation pressure responds favorably to therapy

BACKGROUND

Achalasia diagnosis requires elevated integrated relaxation pressure (IRP; manometric marker of lower esophageal sphincter [LES] relaxation). Yet, some patients exhibit clinical features of achalasia despite normal IRP and have LES dysfunction demonstrable by other means. We hypothesized these patients to exhibit equivalent therapeutic response compared to standard achalasia patients.

METHODS

Symptomatic achalasia-like cases, despite normal IRP, displayed evidence of impaired LES relaxation using rapid drink challenge (RDC), solid swallows during high-resolution manometry, and/or barium esophagogram; were treated with achalasia therapies and compared to standard achalasia patients with raised IRP. Outcomes included equivalence for short- and long-term symptom response and stasis on barium esophagogram.

KEY RESULTS

Twenty-nine normal IRP achalasia cases (14 males, median age 50 year, median Eckardt 6, barium stasis 12 ± 7 cm) and 29 consecutive standard achalasia controls underwent therapy. Among cases, LES dysfunction was most often identified by RDC and/or barium esophagogram. Short-term symptomatic success was equivalent in cases vs controls (90% vs 93%; 95% CI for difference: -19% to 13%). Median short-term (1 vs 1; 95% CI for difference: 0-1) and long-term Eckardt scores (2 vs 1; 95% CI for difference: 0-2) were similar in cases and controls, respectively. Adequate clearance was observed in 67% of cases vs 81% of controls on post-therapy esophagogram.

CONCLUSIONS AND INFERENCES

We described a subset of achalasia patients with normal IRP, but impaired LES relaxation identifiable only on additional provocative tests. These patients benefited from treatment, suggesting that such tests should be performed to increase the number of clinically relevant diagnoses.

Radiofrequency ablation compared with argon plasma coagulation after endoscopic resection of high-grade dysplasia or stage T1 adenocarcinoma in Barrett's esophagus: a randomized pilot study (BRIDE)

BACKGROUND AND AIMS

Endoscopic resection (ER) is safe and effective for Barrett's esophagus (BE) containing high-grade dysplasia (HGD) or mucosal adenocarcinoma (T1A). The risk of metachronous neoplasia is reduced by ablation of residual BE by using radiofrequency ablation (RFA) or argon plasma coagulation (APC). These have not been compared directly. We aimed to recruit up to 100 patients with BE and HGD or T1A confirmed by ER over 1 year in 6 centers in a randomized pilot study.

METHODS

Randomization was 1:1 to RFA or APC (4 treatments allowed at 2-month intervals). Recruitment, retention, dysplasia clearance, clearance of benign BE, adverse events, healthcare costs, and quality of life by using EQ-5D, EORTC QLQ-C30, or OES18 were assessed up to the end of the trial at 12 months.

RESULTS

Of 171 patients screened, 76 were randomized to RFA (n = 36) or APC (n = 40). The mean age was 69.7 years, and 82% were male. BE was <5 cm (n = 27), 5 to 10 cm (n = 45), and >10 cm (n = 4). Sixty-five patients completed the trial. At 12 months, dysplasia clearance was RFA 79.4% and APC 83.8% (odds ratio [OR] 0.7; 95% confidence interval [CI], 0.2-2.6); BE clearance was RFA 55.8%, and APC 48.3% (OR 1.4; 95% CI, 0.5-3.6). A total of 6.1% (RFA) and 13.3% (APC) had buried BE glands. Adverse events (including stricture rate after starting RFA 3/36 [8.3%] and APC 3/37 [8.1%]) and quality of life scores were similar, but RFA cost $27491 more per case than APC.

CONCLUSION

This pilot study suggests similar efficacy and safety but a cost difference favoring APC. A fully powered non-inferiority trial is appropriate to confirm these findings. (Clinical trial registration number: NCT01733719.).

Artificial intelligence for the real-time classification of intrapapillary capillary loop patterns in the endoscopic diagnosis of early oesophageal squamous cell carcinoma: A proof-of-concept study

Background

Intrapapillary capillary loops (IPCLs) represent an endoscopically visible feature of early squamous cell neoplasia (ESCN) which correlate with invasion depth - an important factor in the success of curative endoscopic therapy. IPCLs visualised on magnification endoscopy with Narrow Band Imaging (ME-NBI) can be used to train convolutional neural networks (CNNs) to detect the presence and classify staging of ESCN lesions.

Methods

A total of 7046 sequential high-definition ME-NBI images from 17 patients (10 ESCN, 7 normal) were used to train a CNN. IPCL patterns were classified by three expert endoscopists according to the Japanese Endoscopic Society classification. Normal IPCLs were defined as type A, abnormal as B1-3. Matched histology was obtained for all imaged areas.

Results

This CNN differentiates abnormal from normal IPCL patterns with 93.7% accuracy (86.2% to 98.3%) and sensitivity and specificity for classifying abnormal IPCL patterns of 89.3% (78.1% to 100%) and 98% (92% to 99.7%), respectively. Our CNN operates in real time with diagnostic prediction times between 26.17 ms and 37.48 ms.

Conclusion

Our novel and proof-of-concept application of computer-aided endoscopic diagnosis shows that a CNN can accurately classify IPCL patterns as normal or abnormal. This system could be used as an in vivo, real-time clinical decision support tool for endoscopists assessing and directing local therapy of ESCN.

Radiofrequency ablation for patients with refractory symptomatic anaemia secondary to gastric antral vascular ectasia

Background

Gastric antral vascular ectasia (GAVE) is a rare cause of gastrointestinal bleeding, often causing iron deficiency anaemia. Previous studies have looked at the management of this with argon plasma coagulation, laser therapy and endoscopic band ligation.

Methods

This was a single-centre prospective study to evaluate the efficacy and safety of radiofrequency ablation (RFA) in patients with GAVE with persistent anaemia refractory to at least one session of first-line endoscopic therapy. Patients were treated with a through-the-scope (TTS) radiofrequency catheter at two endoscopic sessions six weeks apart. The primary outcome was change in haemoglobin at six months posttreatment. The secondary outcomes were reduction in blood or iron requirements, endoscopic surface area regression and complications.

Results

Twenty patients were treated. The mean change in haemoglobin at six months was +12.6 g/l (95% confidence interval 11.7-24.3 g/l), paired t test p < 0.001. At six months, three of 14 individuals who had required blood transfusions had ongoing blood transfusions and five of 17 who had required iron had ongoing iron needs. Surface area regression was scored as 74% ± 25% but no correlation was seen between this and other outcomes. Three of 20 patients experienced pain which was managed with oral analgesia. Of the 14 patients who had reached 12-month follow-up, three required retreatment (21%).

Discussion

This small study suggests that RFA is a safe and effective treatment for GAVE. Our study uses the TTS catheter compared to other studies, and demonstrates prolonged improvement in haemoglobin and reduction in blood and iron requirements with a novel assessment of surface area regression.

Risk of lymph node metastases in patients with T1b oesophageal adenocarcinoma: A retrospective single centre experience

AIM

To assess clinical outcomes for submucosal (T1b) oesophageal adenocarcinoma (OAC) patients managed with either surgery or endoscopic eradication therapy.

METHODS

Patients found to have T1b OAC following endoscopic resection between January 2008 to February 2016 at University College London Hospital were retrospectively analysed. Patients were split into low-risk and high-risk groups according to established histopathological criteria and were then further categorised according to whether they underwent surgical resection or conservative management. Study outcomes include the presence of lymph-node metastases, disease-specific mortality and overall survival.

RESULTS

A total of 60 patients were included; 22 patients were surgically managed (1 low-risk and 21 high-risk patients) whilst 38 patients were treated conservatively (12 low-risk and 26 high-risk). Overall, lymph node metastases (LNM) were detected in 10 patients (17%); six of these patients had undergone conservative management and LNM were detected at a median of 4 mo after endoscopic mucosal resection (EMR). All LNM occurred in patients with high-risk lesions and this represented 21% of the total high-risk lesions. Importantly, there was no statistically significant difference in tumor-related deaths between those treated surgically or conservatively (P = 0.636) and disease-specific survival time was also comparable between the two treatment strategies (P = 0.376).

CONCLUSION

T1b tumours without histopathological high-risk markers of LNM can be treated endoscopically with good out-comes. In selected patients, endoscopic therapy may be appropriate for high-risk lesions.

Development of Evidence-Based Surveillance Intervals After Radiofrequency Ablation of Barrett's Esophagus

BACKGROUND & AIMS

Barrett's esophagus (BE) recurs in 25% or more of patients treated successfully with radiofrequency ablation (RFA), so surveillance endoscopy is recommended after complete eradication of intestinal metaplasia (CEIM). The frequency of surveillance is informed only by expert opinion. We aimed to model the incidence of neoplastic recurrence, validate the model in an independent cohort, and propose evidence-based surveillance intervals.

METHODS

We collected data from the United States Radiofrequency Ablation Registry (US RFA, 2004-2013) and the United Kingdom National Halo Registry (UK NHR, 2007-2015) to build and validate models to predict the incidence of neoplasia recurrence after initially successful RFA. We developed 3 categories of risk and modeled intervals to yield 0.1% risk of recurrence with invasive adenocarcinoma. We fit Cox proportional hazards models assessing discrimination by C statistic and 95% confidence limits.

RESULTS

The incidence of neoplastic recurrence was associated with most severe histologic grade before CEIM, age, endoscopic mucosal resection, sex, and baseline BE segment length. In multivariate analysis, a model based solely on most severe pre-CEIM histology predicted neoplastic recurrence with a C statistic of 0.892 (95% confidence limit, 0.863-0.921) in the US RFA registry. This model also performed well when we used data from the UK NHR. Our model divided patients into 3 risk groups based on baseline histologic grade: non-dysplastic BE; indefinite for dysplasia, low-grade dysplasia, and high-grade dysplasia; or intramucosal adenocarcinoma. For patients with low-grade dysplasia, we propose surveillance endoscopy at 1 and 3 years after CEIM; for patients with high-grade dysplasia or intramucosal adenocarcinoma, we propose surveillance endoscopy at 0.25, 0.5, and 1 year after CEIM, then annually.

CONCLUSION

In analyses of data from the US RFA and UK NHR for BE, a much-attenuated schedule of surveillance endoscopy would provide protection from invasive adenocarcinoma. Adherence to the recommended surveillance intervals could decrease the number of endoscopies performed yet identify unresectable cancers at rates less than 1/1000 endoscopies.

Long-term outcomes of the randomized controlled trial comparing 5-aminolaevulinic acid and Photofrin photodynamic therapy for Barrett's oesophagus related neoplasia

OBJECTIVE

Photodynamic therapy (PDT) was used as therapy for early neoplasia associated with Barrett's oesophagus (BE). This is 5-year follow-up of patients enrolled into randomised controlled trial of 5-aminolaevulinic acid (ALA) vs. Photofrin PDT.

METHODS

Biopsies were taken from original Barrett's segment during endoscopic follow up using Seattle protocol. Endoscopic mucosal resection (EMR) ± radiofrequency ablation (RFA) was preferred therapy in patients who failed PDT and/or had recurrent neoplasia.

RESULTS

Fifty eight of 64 patients enrolled in the original trial were followed up including 31 patients treated with ALA PDT (17 patients with ≤6 cm, 14 patients with >6 cm segment of BE) and 27 treated with Photofrin PDT (14 patients with ≤6 cm, 13 patients with >6 cm BE). Initial success was achieved in 65% (20/31) ALA and 48% (13/27) Photofrin patients (p = .289). Thirty five percent patients (7/20) relapsed in ALA group and 54% (7/13) relapsed in Photofrin group (p = .472). At a median follow-up of 67 months, no significant difference was found in long-term complete reversal of intestinal metaplasia (CR-IM) and complete reversal of dysplasia (CR-D) between ALA and Photofrin groups (78% vs. 63%; p = .18; 90% vs. 76%; p = .26). Original length of BE did not alter long-term outcome. Four patients from each group progressed to invasive oesophageal adenocarcinoma. Initial success of ALA PDT was associated with significantly better likelihood of long-term remission (p = .03).

CONCLUSIONS

Initial response to PDT plays key role in long term outcome. RFA ± EMR have, however, become preferred minimally invasive ablative therapy for BE-related neoplasia due to poor efficacy of PDT.

Impaired motility in Barrett's esophagus: A study using high-resolution manometry with physiologic challenge

BACKGROUND

Esophageal dysmotility may predispose to Barrett's esophagus (BE). We hypothesized that high-resolution manometry (HRM) performed with additional physiologic challenge would better delineate dysmotility in BE.

METHODS

Included patients had typical reflux symptoms and underwent endoscopy, HRM with single water swallows and adjunctive testing with solids and rapid drink challenge (RDC) before ambulatory pH-impedance monitoring. BE and endoscopy-negative reflux disease (ENRD) subjects were compared against functional heartburn patient-controls (FHC). Primary outcome was incidence of HRM contractile abnormalities with standard and adjunctive swallows. Secondary outcomes included clearance measures and symptom association on pH-impedance.

KEY RESULTS

Seventy-eight patients (BE 25, ENRD 27, FHC 26) were included. Water swallow contractility was reduced in both BE (median DCI 87 mm Hg/cm/s) and ENRD (442 mm Hg/cm/s) compared to FHC (602 mm Hg/cm/s; P < .001 and .04, respectively). With the challenge of solid swallows and RDC, these parameters improved in ENRD (solids = 1732 mm Hg/cm/s), becoming similar to FHC (1242 mm Hg/cm/s; P = .93), whereas abnormalities persisted in BE (818 mm Hg/cm/s; P < .01 c.f. FHC). In BE and ENRD, reflux events (67 vs 57 events/24 hour) and symptom frequency were similar; yet symptom correlation was significantly better in ENRD compared to BE, which was comparable to FHC (symptom index 30% vs 4% vs 0%, respectively). Furthermore, bolus clearance and exposure times were more pronounced in BE (P < .01).

CONCLUSIONS & INFERENCES

Reduced contractile effectiveness persisted in BE with the more representative esophageal challenge of swallowing solids and free drinking; while in ENRD and FHC peristalsis usually improved, demonstrating peristaltic reserve. Furthermore, symptom association and refluxate clearance were reduced in BE. These factors may underlie BE pathogenesis.

The influence of procedural volume and proficiency gain on mortality from upper GI endoscopic mucosal resection

OBJECTIVE

Endoscopic mucosal resection (EMR) is established for the management of benign and early malignant upper GI disease. The aim of this observational study was to establish the effect of endoscopist procedural volume on mortality.

DESIGN

Patients undergoing upper GI EMR between 1997 and 2012 were identified from the Hospital Episode Statistics database. The primary outcome was 30-day mortality and secondary outcomes were 90-day mortality, requirement for emergency intervention and elective cancer re-intervention. Risk-adjusted cumulative sum (RA-CUSUM) analysis was used to assess patient mortality risk during initial stage of endoscopist proficiency gain and the effect of endoscopist and hospital volume. Mortality was compared before and after the change point or threshold in the RA-CUSUM curve.

RESULTS

11 051 patients underwent upper GI EMR. Endoscopist procedure volume was an independent predictor of 30-day mortality. Fifty-eight per cent of EMR procedures were performed by endoscopists with annual volume of 2 cases or less, and had a higher 30-day and 90-day mortality rate for patients with cancer, 6.1% vs 0.4% (p<0.001) and 12% vs 2.1% (p<0.001), respectively. The requirement for emergency intervention after EMR for cancer was also greater with low volume endoscopists (1.8% vs 0.1%, p=0.002). In patients with cancer, the RA-CUSUM curve change points for 30-day mortality and elective re-intervention were 4 cases and 43 cases, respectively.

CONCLUSIONS

EMR performed by high volume endoscopists is associated with reduced adverse outcomes. In order to reach proficiency, appropriate training and procedural volume accreditation training programmes are needed nationally.

Cost–effectiveness analysis of endoscopic eradication therapy for treatment of high-grade dysplasia in Barrett’s esophagus

Aim: The aim was to evaluate the cost–effectiveness of endoscopic eradication therapy (EET) with combined endoscopic mucosal resection and radiofrequency ablation for the treatment of high-grade dysplasia (HGD) arising in patients with Barrett’s esophagus compared with endoscopic surveillance alone in the UK. Materials & methods: The cost–effectiveness model consisted of a decision tree and modified Markov model. A lifetime time horizon was adopted with the perspective of the UK healthcare system. Results: The base case analysis estimates that EET for the treatment of HGD is cost-effective at a GB£20,000 cost–effectiveness threshold compared with providing surveillance alone for HGD patients (incremental cost–effectiveness ratio: GB£1272). Conclusion: EET is likely to be a cost-effective treatment strategy compared with surveillance alone in patients with HGD arising in Barrett’s esophagus in the UK.

Esophageal neoplasia arising from subsquamous buried glands after an apparently successful photodynamic therapy or radiofrequency ablation for Barrett's associated neoplasia

OBJECTIVE

Photodynamic therapy (PDT) and radiofrequency ablation (RFA) are effective non-surgical options for the treatment of Barrett's esophagus (BE) associated neoplasia. Development of subsquamous intestinal metaplasia after successful PDT and/or RFA is a recognized phenomenon; however, the occurrence of neoplasia arising from buried glands is a rare complication.

METHODS

This is a prospective case series of patients treated with PDT and/or RFA from 1999 to 2014 at University College London Hospital for neoplasia associated with BE, whose outcomes were analyzed retrospectively. Prior to any ablative therapy any visible nodularity was removed with endoscopic mucosal resection (EMR). After successful PDT and/or HALO RFA treatment, defined as a complete reversal of dysplasia and metaplasia, patients underwent endoscopic follow up using the Seattle protocol.

RESULTS

A total of 288 patients were treated, 91 with PDT between 1999 and 2010, 173 with RFA between 2007 and 2014, and 24 with both PDT and RFA for neoplasia associated with BE. Subsquamous neoplasia occurred in seven patients (7/288, 2%). The first patient developed subsquamous invasive adenocarcinoma and underwent curative surgery. Another five patients with subsquamous neoplasia (either high-grade dysplasia or intramucosal cancer) were treated successfully with EMR. The final patient developed subsquamous invasive esophagogastric junctional adenocarcinoma with liver metastases.

CONCLUSION

Development of subsquamous neoplasia after an apparently successful PDT and/or RFA is a rare but recognized complication. Clinicians should be aware of this phenomenon and have a low threshold for performing an EMR. Thorough surveillance following successful PDT and/or RFA ensuring high-quality endoscopy is required.

Role of body composition and metabolic profile in Barrett's oesophagus and progression to cancer

BACKGROUND AND AIMS

The aim of this study was to evaluate the risk for Barrett's oesophagus (BE) on the basis of body composition, metabolic pathways, adipokines and metabolic syndrome (MS), as well as their role in cancer progression.

METHODS

In patients with and without BE at gastroscopy, data on MS, BMI, waist/hip ratio for abdominal obesity (AO) and body fat percentage by bioimpedance were obtained. Fasting plasma glucose, insulin, HbA1c, lipid, serum adiponectin and leptin levels were measured. The homoeostasis model assessment (HOMA-IR) was used to estimate insulin resistance. Histological findings for BE were correlated with the above parameters. Risk factors for BE identified using univariate analysis were entered into a multivariate logistic regression analysis.

RESULTS

A total of 250 patients and 224 controls (F/M: 189/285, mean age 58.08±15.51 years) were enroled. In the BE and control groups, 39.6 versus 31.3% were overweight, 32 versus 22.8% were obese, 75.6 versus 51.3% had AO, and 28.1 versus 18.9% were metabolically obese, respectively. AO [odds ratio (OR) 3.08], increased body fat percentage (OR 2.29), and higher BMI (overweight: OR 2.04; obese: OR 2.26) were significantly associated with BE. A positive trend was found in Normal Weight Obese Syndrome (OR 1.69). MS was associated with BE (overweight: OR 3.05; obese: OR 5.2; AO: OR 8.08). Insulin levels (P=0.05) and HOMA-IR (P<0.001) were higher in BE. AO was the only independent risk factor associated with BE (OR 1.65; P=0.02) and high-grade dysplasia (OR 2.44) on multivariate analysis.

CONCLUSION

AO was strongly associated with BE and dysplasia. BE was associated with MS and higher insulin/HOMA-IR, suggesting the activation of specific metabolic pathways in patients with altered body composition.

Radiofrequency ablation for Barrett's dysplasia: past, present and the future?

Barrett's oesophagus is the only know pre-cursor to oesophageal adenocarcinoma. The incidence of OAC is growing rapidly in the western world with a poor prognosis for most with a 5-year survival of only 15%. The approach to treating patients with neoplasia arising within BE has dramatically changed in the past 5 years. Resection of visible lesions with endoscopic mucosal resection followed by field ablation with radio-frequency ablation is now the accepted standard of care in these patients worldwide. This combined approach has shown high rates of disease reversal in several high quality clinical trials but also large volume registry studies. As well as being a minimally invasive and oesophageal sparing interventions compared to surgery with oesophagectomy, endoscopic therapy has proved to be safe and emerging long-term data show sustained benefit in the majority of patients and low rates of cancer progression. However, in a sub-group of patients, recurrences have been reported after successful endoscopic therapy making it mandatory to follow these patients post therapy. Improvements in endoscopic imaging continue to aid early diagnosis, and in turn, this will allow clinicians the ability to offer patient's treatment at an early stage.

Evaluation of a minimally invasive cell sampling device coupled with assessment of trefoil factor 3 expression for diagnosing Barrett's esophagus: a multi-center case-control study

BACKGROUND

Barrett's esophagus (BE) is a commonly undiagnosed condition that predisposes to esophageal adenocarcinoma. Routine endoscopic screening for BE is not recommended because of the burden this would impose on the health care system. The objective of this study was to determine whether a novel approach using a minimally invasive cell sampling device, the Cytosponge, coupled with immunohistochemical staining for the biomarker Trefoil Factor 3 (TFF3), could be used to identify patients who warrant endoscopy to diagnose BE.

METHODS AND FINDINGS

A case-control study was performed across 11 UK hospitals between July 2011 and December 2013. In total, 1,110 individuals comprising 463 controls with dyspepsia and reflux symptoms and 647 BE cases swallowed a Cytosponge prior to endoscopy. The primary outcome measures were to evaluate the safety, acceptability, and accuracy of the Cytosponge-TFF3 test compared with endoscopy and biopsy. In all, 1,042 (93.9%) patients successfully swallowed the Cytosponge, and no serious adverse events were attributed to the device. The Cytosponge was rated favorably, using a visual analogue scale, compared with endoscopy (p < 0.001), and patients who were not sedated for endoscopy were more likely to rate the Cytosponge higher than endoscopy (Mann-Whitney test, p < 0.001). The overall sensitivity of the test was 79.9% (95% CI 76.4%-83.0%), increasing to 87.2% (95% CI 83.0%-90.6%) for patients with ≥3 cm of circumferential BE, known to confer a higher cancer risk. The sensitivity increased to 89.7% (95% CI 82.3%-94.8%) in 107 patients who swallowed the device twice during the study course. There was no loss of sensitivity in patients with dysplasia. The specificity for diagnosing BE was 92.4% (95% CI 89.5%-94.7%). The case-control design of the study means that the results are not generalizable to a primary care population. Another limitation is that the acceptability data were limited to a single measure.

CONCLUSIONS

The Cytosponge-TFF3 test is safe and acceptable, and has accuracy comparable to other screening tests. This test may be a simple and inexpensive approach to identify patients with reflux symptoms who warrant endoscopy to diagnose BE.

Multicenter, randomized, controlled trial of confocal laser endomicroscopy assessment of residual metaplasia after mucosal ablation or resection of GI neoplasia in Barrett's esophagus

BACKGROUND

Endoscopic ablation is an accepted standard for neoplasia in Barrett's esophagus (BE). Eradication of all glandular mucosa in the distal esophagus cannot be reliably determined at endoscopy.

OBJECTIVE

To assess if use of probe-based confocal laser endomicroscopy (pCLE) in addition to high-definition white light (HDWL) could aid in determination of residual BE.

DESIGN

Prospective, multicenter, randomized, clinical trial.

SETTING

Academic medical centers.

PATIENTS

Patients with Barrett's esophagus undergoing ablation.

INTERVENTION

After an initial attempt at ablation, patients were followed-up either with HDWL endoscopy or HDWL plus pCLE, with treatment of residual metaplasia or neoplasia based on endoscopic findings and pCLE used to avoid overtreatment.

MAIN OUTCOME MEASUREMENTS

The proportion of optimally treated patients, defined as those with residual BE who were treated and had complete ablation plus those without BE who were not treated and had no evidence of disease at follow-up.

RESULTS

The study was halted at the planned interim analysis based on a priori criteria. After enrollment was halted, all patients who had been randomized were followed to study completion. Among the 119 patients with follow-up, there was no difference in the proportion of patients achieving optimal outcomes in the two groups (15/57, 26% for HDWL; 17/62, 27% with HDWL + pCLE). Other outcomes were similar in the two groups.

LIMITATIONS

The study was closed after the interim analysis due to low conditional power resulting from lack of difference between groups as well as higher-than-expected residual Barrett's esophagus in both arms.

CONCLUSION

This study yields no evidence that the addition of pCLE to HDWL imaging for detection of residual Barrett's esophagus or neoplasia can provide improved treatment.

Photodynamic therapy using 5-aminolaevulinic acid for the treatment of dysplasia in Barrett's oesophagus

BACKGROUND

5-Aminolaevulinic acid (ALA) is the naturally occurring metabolic precursor of an endogenously formed photosensitiser, protoporphyrin IX. It is used topically to treat benign and malignant skin disorders by a process called photodynamic therapy (PDT). Recently, data are emerging on its systemic use in the treatment of dysplasia in Barrett's oesophagus.

OBJECTIVE

To investigate the use of ALA-PDT for the treatment of dysplasia and early cancer in Barrett's oesophagus.

METHODS

A systematic literature review and synopsis is given.

CONCLUSION

ALA is an attractive alternative to the currently approved photosensitiser (porfimer sodium) due to its oral route of administration, shorter generalised skin photosensitivity period and lower rate of stricture formation. The studies presented demonstrate that ALA-PDT is both safe and effective for the treatment of dysplasia and early cancer in Barrett's oesophagus.

Cyclin A immunocytology as a risk stratification tool for Barrett's esophagus surveillance

PURPOSE

Endoscopic surveillance of Barrett's esophagus (BE) by histopathologic biopsy assessment is suboptimal. A proliferation marker, minichromosome maintenance protein 2, has potential as a biomarker but lacks specificity. We hypothesized that cyclin A, which detects a proportion of proliferating cells, would be more specific. Because cytologic sampling has clinical advantages, we also evaluated the efficacy of cyclin A in endoscopic brushing samples.

EXPERIMENTAL DESIGN

A cross-sectional cyclin A immunostaining study was done in 77 patients attending for BE surveillance and 17 patients undergoing evaluation of esophageal adenocarcinoma. The control tissues were as follows: 30 squamous esophagus, 20 gastric antrum, and 13 duodenum. A nested case-control study was done within the same surveillance cohort (16 progressors compared with 32 matched controls) to determine the relative risk for progression. Immunocytology was done for endoscopic brushings collected prospectively from 75 BE +/- dysplasia and 33 esophageal adenocarcinomas.

RESULTS

Surface expression of cyclin A in BE samples correlated with the degree of dysplasia (P = 0.016). In the case-control cohort, patients with biopsies expressing cyclin A at the surface were more likely to progress to adenocarcinoma than those who did not (odds ratio, 7.5; 95% confidence interval, 1.8-30.7). The sensitivity and specificity of cyclin A expression in brushings for the detection of high-grade dysplasia and cancer patients were 97.8% and 58.7%, respectively. The associated negative predictive value was 97.4%.

CONCLUSIONS

Cyclin A immunopositivity correlates with cancer risk. Application of this marker to endoscopic brushings could be used as a first step to identify BE patients with the highest risk of progression.

"Minimum pruning", "minimal pruning" and "physiological pruning" as new techniques in grey mould agronomic eco-compatible (natural) control. Researches and considerations

The aim of this work was to find agronomic eco-compatible ("natural") control solutions against grey mould of grapevine too. Our researches about "minimum pruning", "minimal pruning" and "physiological pruning" started in 1980, and in 1983 with specific relation to grey mould on vines of Merlot, Cabernet sauvignon and Chardonnay previously set in vegetative and productive growth balance. These researches were conducted to verify the affordability of innovative winter pruning techniques like "minimum pruning", "minimal pruning" and the so called 'physiological pruning", in the natural agronomic eco-compatible grey mould control. As a result we found that the new techniques contribute to limit the incidence of grey mould; especially "physiological pruning" followed by "minimal pruning" and 'minimum pruning". The best results were observed on Chardonnay, followed by Merlot and Cabernet sauvignon.

Cell cycle phase abnormalities do not account for disordered proliferation in Barrett's carcinogenesis

Barrett's esophagus (BE) epithelium is the precursor lesion for esophageal adenocarcinoma. Cell cycle proteins have been advocated as biomarkers to predict the malignant potential in BE. However, whether disruption of the cell cycle plays a causal role in Barrett's carcinogenesis is not clear. Specimens from the Barrett's dysplasia-carcinoma sequence were immunostained for cell cycle phase markers (cyclin D1 for G1; cyclin A for S, G2, and M; cytoplasmic cyclin B1 for G2; and phosphorylated histone 3 for M phase) and expressed as a proportion of proliferating cells. Flow cytometric analysis of the cell cycle phase of prospective biopsies was also performed. The proliferation status of nondysplastic BE was similar to gastric antrum and D2, but the proliferative compartment extended to the luminal surface. In dysplastic samples, the number of proliferating cells correlated with the degree of dysplasia (P <.001). The overall levels of cyclins A and B1 correlated with the degree of dysplasia (P <.001). However, the cell cycle phase distribution measured with both immunostaining and flow cytometry was conserved during all stages of BE, dysplasia, and cancer. Hence, the increased proliferation seen in Barrett's carcinogenesis is due to abnormal cell cycle entry or exit, rather than a primary abnormality within the cell cycle.

Elastic scattering spectroscopy for detection of dysplasia in Barrett's esophagus

Elastic scattering is a cheap and simple-to-use tool that holds the promise of rapid and accurate diagnosis in many applications,including dysplasia arising in Barrett's esophagus. It is being developed as an optical biopsy technique, but preliminary work shows that it may be possible to use this approach as a field detection device. Even as a point measurement technique or optical biopsy, the technique may become an invaluable tool to endoscopists. This article focuses on elastic scattering spectroscopy (also known as diffuse reflectance spectroscopy).