Chromoendoscopy with indigo carmine dye added to acetic acid in the diagnosis of gastric neoplasia: a prospective comparative study

L-Menthol for Color Difference Change Between Early Gastric Cancer and Surrounding Mucosa: A Prospective Study

BACKGROUND

L-Menthol sprayed on early gastric cancer (EGC) has been reported to improve the visibility of the lesion. However, its impact when used in combination with novel image-enhanced endoscopy has not been investigated.

AIM

This study aimed to evaluate the visual effect of spraying L-menthol on EGC under linked color imaging (LCI).

METHODS

This open-label, single-arm, prospective study investigated the color difference between EGC and the surrounding mucosa (ΔEG) before and after spraying L-menthol. The primary endpoint was the percentage of lesions with ΔEG ≥ 5 on LCI. The percentage of lesions with ΔEG  ≥ 5 on white light imaging (WLI) and blue laser imaging (BLI), ΔEG before and after spraying L-menthol, and percentage of lesions with increased ΔEG after spraying L-menthol constituted the secondary endpoints.

RESULTS

Sixty patients were included in the final analysis. 100% lesions had ΔEG ≥ 5, both before and after spraying L-menthol on LCI, with similar results observed in WLI as well as BLI. The median ΔEG on LCI, WLI, and BLI increased after spraying L-menthol (LCI: 16.9 vs. 21.5, p < 0.01; WLI: 10.4 vs. 13.4, p < 0.01; BLI; 12.1 vs. 15.7, before and after, respectively, p < 0.01); and LCI demonstrated the highest percentage of lesions with increased ΔEG (LCI, WLI, and BLI: 98.3%, 81.7%, and 76.7%, respectively, p < 0.01).

CONCLUSION

Although spraying L-menthol did not improve the visibility of EGC under LCI observation, a significant increase in ΔEG was observed in LCI (jRCTs 021200027).

Recent advances in endoscopic management of gastric neoplasms

The development and clinical application of new diagnostic endoscopic technologies such as endoscopic ultrasonography with biopsy, magnification endoscopy, and narrow-band imaging, more recently supplemented by artificial intelligence, have enabled wider recognition and detection of various gastric neoplasms including early gastric cancer (EGC) and subepithelial tumors, such as gastrointestinal stromal tumors and neuroendocrine tumors. Over the last decade, the evolution of novel advanced therapeutic endoscopic techniques, such as endoscopic mucosal resection, endoscopic submucosal dissection, endoscopic full-thickness resection, and submucosal tunneling endoscopic resection, along with the advent of a broad array of endoscopic accessories, has provided a promising and yet less invasive strategy for treating gastric neoplasms with the advantage of a reduced need for gastric surgery. Thus, the management algorithms of various gastric tumors in a defined subset of the patient population at low risk of lymph node metastasis and amenable to endoscopic resection, may require revision considering upcoming data given the high success rate of en bloc resection by experienced endoscopists. Moreover, endoscopic surveillance protocols for precancerous gastric lesions will continue to be refined by systematic reviews and meta-analyses of further research. However, the lack of familiarity with subtle endoscopic changes associated with EGC, as well as longer procedural time, evolving resection techniques and tools, a steep learning curve of such high-risk procedures, and lack of coding are issues that do not appeal to many gastroenterologists in the field. This review summarizes recent advances in the endoscopic management of gastric neoplasms, with special emphasis on diagnostic and therapeutic methods and their future prospects.

Image-enhanced endoscopy in the diagnosis of gastric premalignant conditions and gastric cancer

Diagnosis of early gastric cancer and its precancerous lesions remains a challenge for great part of western endoscopists. Changes seen in the mucosal pattern are generally subtle and hence difficult to identify. In this article, we will review the usefulness of conventional and virtual chromoendoscopy and magnification endoscopy in the recognition and classification of these lesions.

Endoscopic advances in the management of gastric cancer and premalignant gastric conditions

Gastric cancer is the fifth most common cancer and in 2018, it was the third most common cause of cancer-related deaths worldwide. Endoscopic advances continue to be made for the diagnosis and management of both early gastric cancer and premalignant gastric conditions. In this review, we discuss the epidemiology and risk factors of gastric cancer and emphasize the differences in early vs late-stage gastric cancer outcomes. We then discuss endoscopic advances in the diagnosis of early gastric cancer and premalignant gastric lesions. This includes the implementation of different imaging modalities such as narrow-band imaging, chromoendoscopy, confocal laser endomicroscopy, and other experimental techniques. We also discuss the use of endoscopic ultrasound in the diagnosis and staging of early gastric cancer. We then discuss the endoscopic advances made in the treatment of these conditions, including endoscopic mucosal resection, endoscopic submucosal dissection, and hybrid techniques such as laparoscopic endoscopic cooperative surgery. Finally, we comment on the current suggested recommendations for surveillance of both gastric cancer and its premalignant conditions.

Endoscopic diagnosis of early gastric cancer

Background: Among the types of gastric cancer, the proportion of early gastric cancer has shown a steady increase because the national screening programs have been conducted in Korea. Accordingly, the paradigm shift of the treatment procedure from surgical gastrectomy to endoscopic resection for selected early gastric cancer has accelerated recently. For successful treatment of early gastric cancer, early detection is essential to accurately predict the histological type, depth of invasion, and horizontal margins of the tumor.Current Concepts: The diagnosis of early gastric cancer and selection of treatment procedures comprises the following steps: (1) presence diagnosis, (2) qualitative diagnosis, and (3) quantitative diagnosis. Presently, early gastric cancer diagnosis is based on the endoscopic detection of a demarcated lesion and irregularity of the mucosal surface or color pattern. If a lesion is diagnosed as early gastric cancer, qualitative and quantitative diagnostic processes should be conducted. Qualitative diagnosis predicts the histological type (differentiated vs. undifferentiated), whereas quantitative diagnosis predicts the invasion depth and horizontal margins of the lesion. The diagnostic processes are based on the macroscopic morphology and color of the lesion, while sometimes using chromoendoscopy, image-enhanced endoscopy, and magnifying endoscopy.Discussion and Conclusion: If gastric cancer is detected at an early stage, most cases can be treated only by endoscopic resection. Therefore, endoscopists should have systematic knowledge regarding the findings of early gastric cancer for timely detection and appropriate selection of the treatment procedure.

Gastric intestinal metaplasia: when to treat? How to treat?

PURPOSE OF REVIEW

Gastric intestinal metaplasia (GIM) is an attractive target for surveillance and treatment as it can progress to gastric adenocarcinoma (GAC). Yet, GIM remains a challenging area for clinicians as most patients do not progress to cancer, and there are conflicting data regarding the benefits of surveillance and therapy. This review aims to summarize recently published GIM surveillance guidelines, to discuss, which patients with GIM may benefit from treatment, and to review pivotal and recent literature on GIM therapy.

RECENT FINDINGS

Guidelines published by American, British, and European gastroenterology societies do not recommend universal surveillance, but do suggest endoscopic surveillance in patients with risk factors for progression to GAC. Although light examination for at least 7 min and mapping biopsies may increase yield for dysplasia and GAC. In randomized trials, Helicobacter pylori eradication reduced risk of dysplasia and cancer. In GIM with visible dysplasia and early-stage GAC, endoscopic resection improves quality of life without reducing survival compared with surgery. Endoscopic ablation therapies have shown promise for invisible or extensive dysplasia.

SUMMARY

Endoscopic resection is appropriate for visible dysplasia and early-stage GAC without high-risk features that persists despite H. pylori eradication therapy. Prospective studies are needed to assess the utility of endoscopic ablation in GIM.

Association between mucin phenotype and lesion border detection using acetic acid-indigo carmine chromoendoscopy in early gastric cancers

BACKGROUND

For successful treatment of early gastric cancers (EGCs), it is crucial to define the horizontal border of the lesion with high accuracy. Acetic acid-indigo carmine (AI) chromoendoscopy has been used to determine the horizontal border in EGCs, but this technique is less potent in certain situations. Mucin phenotype in gastric cancers refers to biological differences in precursor lesions and differences in histopathologic findings, and it might affect AI chromoendoscopy findings. We aimed to investigate the association between mucin phenotype and AI chromoendoscopy findings in EGCs.

METHODS

We prospectively evaluated 126 lesions in 126 patients with endoscopically diagnosed EGCs. Conventional endoscopy and AI chromoendoscopy findings of these lesions before treatment were prospectively analyzed. The border distinction between the lesion and surrounding mucosa was classified as distinct or indistinct on conventional endoscopy and AI chromoendoscopy, respectively. Mucin phenotypes were classified as gastric, intestinal, gastrointestinal, or null type by immunohistochemistry.

RESULTS

The lesion borders were distinct in 46.8% (59/126) of the lesions assessed using conventional endoscopy and in 73.0% (92/126) of those assessed with AI chromoendoscopy (p < 0.001). The border distinction rate of differentiated-type cancers on AI chromoendoscopy was significantly higher than that on conventional endoscopy (66/71 [93.0%] vs. 34/71 [47.9%], p < 0.001), but the border distinction rate of undifferentiated-type cancers on AI chromoendoscopy was not different from that on conventional endoscopy (26/55 [47.3%] vs. 25/55 [45.5%], p = 0.848). Compared with conventional endoscopy, AI chromoendoscopy identified borders in a significantly higher percentage of gastric, intestinal, and gastrointestinal mucin types; however, there was no difference in AI chromoendoscopy findings according to the mucin phenotype (p = 0.271).

CONCLUSION

AI chromoendoscopy was effective in horizontal border delineation in differentiated-type EGCs, but not in undifferentiated-type EGCs. Mucin phenotype had no effect on border distinction using AI chromoendoscopy.

Real-World Experience of Endoscopic Submucosal Dissection for Ulcerative Colitis-Associated Neoplasia

Introduction

Patients with ulcerative colitis (UC) have an increased risk of colorectal cancer. Some studies have recently investigated endoscopic resection of UC-associated neoplasia (UCAN), but the indications for endoscopic resection of UCAN remain controversial. This study sought to clarify the problems encountered in endoscopic submucosal dissection (ESD) for UCAN.

Methods

Seventeen lesions in 12 patients with UCAN (UCAN group) and 913 epithelial lesions in 824 control patients without UC (non-UC group) were evaluated. Both groups underwent ESD between January 2010 and December 2017 at Toranomon Hospital, Tokyo, Japan. Treatment outcomes of the 2 groups were compared retrospectively.

Results

Univariate analysis showed that the mean tumor size was significantly smaller in the UCAN group than in the non-UC group (25.1 ± 26.7 mm vs. 31.9 ± 19.0; p = 0.0023); however, the R0 resection rate was significantly lower in the UCAN group (70.6 vs. 92.9%; p = 0.001). Multivariate analysis showed a significantly lower negative horizontal margin rate in the UCAN group (odds ratio 11.3, 95% confidence interval 3.588-34.525; p = 0.000).

Discussion/Conclusion

ESD for UCAN is associated with a low-negative horizontal margin rate. When performing ESD for UCAN, it is important to evaluate the accuracy of the UCAN demarcation line, especially for flat lesions, using white-light imaging and chromoendoscopy as well as other modalities, including biopsy of surrounding tissues.

Detection of early stage gastric cancers in screening laser endoscopy using linked color imaging for patients with atrophic gastritis

BACKGROUND AND AIMS

Laser endoscopy involves blue laser imaging in bright mode (BLI-bright). Linked color imaging (LCI) is superior to white light imaging (WLI) for detecting gastric cancers. This study aimed to detect gastric cancers on screening endoscopy using not only WLI but also BLI-bright and LCI in patients with atrophic gastritis.

PATIENTS AND METHODS

A total of 500 patients with atrophic gastritis undergoing screening esophagogastroduodenoscopy were included. The gastric lumen was observed in the WLI mode, followed by the LCI and BLI-bright modes. When gastric neoplasms were suspected, the mode was changed to WLI, and we sprayed indigo carmine. Finally, biopsy specimens were taken for those lesions and pathological diagnosis was made. We compared the size, morphology, and color of gastric neoplasms found by the first WLI mode and those detected by only the LCI mode or BLI-bright mode.

RESULTS

We detected 16 gastric neoplasms (3.2%), of which 13 were early gastric cancers (EGCs) and three were gastric adenomas. Ten EGCs and two gastric adenomas (75%) were detected by the first WLI mode; three EGCs and one gastric adenoma (25%) were missed by the first WLI mode and were detected by the LCI mode or BLI-bright mode. All were less than 1 cm in diameter and were reddish. Mean diameter of the lesions was significantly less for LCI-detected or BLI-bright-detected lesions than for WLI-detected lesions (7.8 vs 21.2 mm).

CONCLUSIONS

Laser endoscopy is useful for detecting EGCs by LCI for patients with atrophic gastritis.

Systematic Endoscopic Approach to Early Gastric Cancer in Clinical Practice

Early gastric cancers (EGCs) are defined as gastric cancers confined to the mucosa or submucosa, regardless of regional lymph node metastasis. The proportion of EGCs has been increasing due to the increase in screening endoscopy for gastric cancers; therefore, the paradigm shift from surgical resection to endoscopic resection as a treatment modality for selected EGCs is accelerating. For successful endoscopic resection of EGCs, it is important to detect EGCs at an early stage and to accurately predict the histological type, depth of invasion, and horizontal margins of the tumor. The diagnostic process of EGCs can be divided into three steps: presence diagnosis, qualitative diagnosis, and quantitative diagnosis. The presence diagnosis of EGCs is mainly based on two endoscopic findings: a well-demarcated lesion and irregularity in the color/surface pattern. Qualitative diagnosis refers to the prediction of histological type, which is mainly possible based on the macroscopic shape and color of the lesion. Quantitative diagnosis of EGCs consists of predicting the depth of invasion by detailed examination of the macroscopic morphology and determining horizontal margins using chromoendoscopy. Although advanced diagnostic modalities, such as endosonography or magnifying endoscopy, are helpful for the qualitative and quantitative diagnosis of EGCs, these modalities are not available in most hospitals. Therefore, it is still very important to evaluate EGCs systematically during conventional endoscopy for successful endoscopic treatment.

Quality in diagnostic upper gastrointestinal endoscopy for the detection and surveillance of gastric cancer precursor lesions: Position paper of AEG, SEED and SEAP

This position paper, sponsored by the Asociación Española de Gastroenterología [Spanish Association of Gastroenterology], the Sociedad Española de Endoscopia Digestiva [Spanish Gastrointestinal Endoscopy Society] and the Sociedad Española de Anatomía Patológica [Spanish Anatomical Pathology Society], aims to establish recommendations for performing an high quality upper gastrointestinal endoscopy for the screening of gastric cancer precursor lesions (GCPL) in low-incidence populations, such as the Spanish population. To establish the quality of the evidence and the levels of recommendation, we used the methodology based on the GRADE system (Grading of Recommendations Assessment, Development and Evaluation). We obtained a consensus among experts using a Delphi method. The document evaluates different measures to improve the quality of upper gastrointestinal endoscopy in this setting and makes recommendations on how to evaluate and treat the identified lesions. We recommend that upper gastrointestinal endoscopy for surveillance of GCPL should be performed by endoscopists with adequate training, administering oral premedication and use of sedation. To improve the identification of GCPL, we recommend the use of high definition endoscopes and conventional or digital chromoendoscopy and, for biopsies, NBI should be used to target the most suspicious areas of intestinal metaplasia. Regarding the evaluation of visible lesions, the risk of submucosal invasion should be evaluated with magnifying endoscopes and endoscopic ultrasound should be reserved for those with suspected deep invasion. In lesions amenable to endoscopic resection, submucosal endoscopic dissection is considered the technique of choice.

Clinical Features of False-Negative Early Gastric Cancers: A Retrospective Study of Endoscopic Submucosal Dissection Cases

Background

We frequently encounter early gastric cancer (EGC) that could not be detected in the previous esophagogastroduodenoscopy even if the procedure was annually performed. However, little evidence exists regarding the characteristics of false-negative EGCs. Our aim was to reveal the clinical features of false-negative EGCs.

Methods

We retrospectively reviewed cases of endoscopic submucosal dissection (ESD) for EGCs in Fukuchiyama City Hospital between January 2013 and May 2019. False-negative EGCs were defined as EGCs within 3 years of negative endoscopy. We evaluated the clinical characteristics of false-negative and initially detected EGCs and the difference in the detected and last missed endoscopy in false-negative EGCs. The miss rates of false-negative EGCs were compared between trainees (nonboard-certified endoscopists) and experienced endoscopists (board-certified endoscopists); thereafter, the characteristics of false-negative EGCs missed by trainees were investigated.

Results

Of 219 cases, 119 were classified as false-negative EGCs. False-negative EGCs were characterized as smaller lesions, which presented with normal color or gastritis-like appearance, and were diagnosed after ESD and H. pylori eradication (P < 0.01). The rate of trainees in the last missed endoscopy was significantly higher than that in the detected endoscopy. The miss rate of false-negative EGC by trainees was higher than that of experienced endoscopists but not significantly different (0.70% vs. 0.57%, P = 0.08). The false-negative EGCs missed by trainees were characterized as reddish or well-differentiated lesions, which were located in the lower or lesser curvature of the stomach (P < 0.05).

Conclusion

The characteristics of false-negative EGCs were similar to those of H. pylori-eradicated EGC. Procedures with shortened examination time and those performed by trainees were risk factors of missing false-negative EGCs. Trainees should pay attention to reddish or well-differentiated EGCs located in the lower or lesser curvature of the stomach.

A deep learning method for delineating early gastric cancer resection margin under chromoendoscopy and white light endoscopy

BACKGROUND

Accurate delineation of cancer margins is critical for endoscopic curative resection. This study aimed to train and validate real-time fully convolutional networks for delineating the resection margin of early gastric cancer (EGC) under indigo carmine chromoendoscopy (CE) or white light endoscopy (WLE), and evaluated its performance and that of magnifying endoscopy with narrow-band imaging (ME-NBI).

METHODS

We collected CE and WLE images of EGC lesions to train fully convolutional networks ENDOANGEL. ENDOANGEL was tested both on stationary images and endoscopic submucosal dissection (ESD) videos. The accuracy and reliability of ENDOANGEL and NBI-dependent delineation were further evaluated by a novel endoscopy-pathology point-to-point marking.

RESULTS

ENDOANGEL had an accuracy of 85.7% in the CE images and 88.9% in the WLE images under an overlap ratio threshold of 0.60 in comparison with the manual markers labeled by the experts. In the ESD videos, the resection margins predicted by ENDOANGEL covered all areas of high-grade intraepithelial neoplasia and cancers. The minimum distance between the margins predicted by ENDOANGEL and the histological cancer boundary was 3.44 ± 1.45 mm which outperformed the resection margin based on ME-NBI.

CONCLUSIONS

ENDOANGEL has the potential to assist endoscopists in delineating the resection extent of EGC under CE or WLE during ESD.

An Asian consensus on standards of diagnostic upper endoscopy for neoplasia

BACKGROUND

This is a consensus developed by a group of expert endoscopists aiming to standardise the preparation, process and endoscopic procedural steps for diagnosis of early upper gastrointestinal (GI) cancers.

METHOD

The Delphi method was used to develop consensus statements through identification of clinical questions on diagnostic endoscopy. Three consensus meetings were conducted to consolidate the statements and voting. We conducted a systematic literature search on evidence for each statement. The statements were presented in the second consensus meeting and revised according to comments. The final voting was conducted at the third consensus meeting on the level of evidence and agreement.

RESULTS

Risk stratification should be conducted before endoscopy and high risk endoscopic findings should raise an index of suspicion. The presence of premalignant mucosal changes should be documented and use of sedation is recommended to enhance detection of superficial upper GI neoplasms. The use of antispasmodics and mucolytics enhanced visualisation of the upper GI tract, and systematic endoscopic mapping should be conducted to improve detection. Sufficient examination time and structured training on diagnosis improves detection. Image enhanced endoscopy in addition to white light imaging improves detection of superficial upper GI cancer. Magnifying endoscopy with narrow-band imaging is recommended for characterisation of upper GI superficial neoplasms. Endoscopic characterisation can avoid unnecessary biopsy.

CONCLUSION

This consensus provides guidance for the performance of endoscopic diagnosis and characterisation for early gastric and oesophageal neoplasia based on the evidence. This will enhance the quality of endoscopic diagnosis and improve detection of early upper GI cancers.

Evaluation of the visibility of early gastric cancer using linked color imaging and blue laser imaging

Background

Blue laser imaging (BLI) and linked color imaging (LCI) are the color enhancement features of the LASEREO endoscopic system, which provide a narrow band light observation function and expansion and reduction of the color information, respectively.

Methods

We examined 82 patients with early gastric cancer (EGC) diagnosed between April 2014 and August 2015. Five expert and 5 non-expert endoscopists retrospectively compared images obtained on non-magnifying BLI bright mode (BLI-BRT) and LCI with those obtained via conventional white light imaging (WLI). Interobserver agreement was also assessed.

Results

In experts’ evaluation of the images, an improvement in visibility was observed in 73% (60/82) and 20% (16/82) of cases under LCI and BLI-BRT, respectively. In non-experts’ evaluation of the images, an improvement in visibility was observed in 76.8% (63/82) and 24.3% (20/82) of cases under LCI and BLI-BRT, respectively. There were no significant differences between experts and non-experts in the evaluation of the images. The improvement in visibility was significantly higher with LCI than with BLI-BRT in experts and non-experts (p < 0.01). With regard to tumor color on WLI, the improvement in the visibility of reddish and whitish tumors was significantly higher than that of isochromatic tumors when LCI was used. The improvement in visibility with LCI was observed in 71% (12/17) and 74% (48/65) of patients with and without Helicobacter pylori (Hp) eradication, respectively; no significant difference in improvement was observed between these groups. The interobserver agreement was good to satisfactory at ≥ 0.62.

Conclusions

In conclusion, our study showed that LCI improved the visibility of EGC, regardless of the level of endoscopists’ experience or Hp eradication in patients, particularly for EGCs with a reddish or whitish color. The improvement in visibility was significantly higher with LCI than that with BLI.

Barrett’s oesophagus: Current controversies

Oesophageal adenocarcinoma is rapidly increasing in Western countries. This tumour frequently presents late in its course with metastatic disease and has a very poor prognosis. Barrett’s oesophagus is an acquired condition whereby the native squamous mucosa of the lower oesophagus is replaced by columnar epithelium following prolonged gastro-oesophageal reflux and is the recognised precursor lesion for oesophageal adenocarcinoma. There are multiple national and society guidelines regarding screening, surveillance and management of Barrett’s oesophagus, however all are limited regarding a clear evidence base for a well-demonstrated benefit and cost-effectiveness of surveillance, and robust risk stratification for patients to best use resources. Currently the accepted risk factors upon which surveillance intervals and interventions are based are Barrett’s segment length and histological interpretation of the systematic biopsies. Further patient risk factors including other demographic features, smoking, gender, obesity, ethnicity, patient age, biomarkers and endoscopic adjuncts remain under consideration and are discussed in full. Recent evidence has been published to support earlier endoscopic intervention by means of ablation of the metaplastic Barrett’s segment when the earliest signs of dysplasia are detected. Further work should concentrate on establishing better risk stratification and primary and secondary preventative strategies to reduce the risk of adenocarcinoma of the oesophagus.

Clinical Usefulness of the VS Classification System Using Magnifying Endoscopy with Blue Laser Imaging for Early Gastric Cancer

BACKGROUND

Blue laser imaging (BLI) enables the acquisition of more information from tumors' surfaces compared with white light imaging. Few reports confirm the validity of magnifying endoscopy (ME) with BLI (ME-BLI) for early gastric cancer (EGC). We aimed to assess the detailed endoscopic findings from EGCs using ME-BLI.

METHODS

We enrolled 386 consecutive patients with 417 EGCs that were diagnosed using ME-BLI and resected by endoscopic submucosal dissection. Using the VS classification system, three highly experienced endoscopists (HEEs) and three less experienced endoscopists (LEEs) evaluated the demarcation line (DL), microsurface pattern (MSP), and microvascular pattern (MVP) within the endoscopic images of EGCs obtained using ME-BLI, assigning high-confidence (HC) or low-confidence (LC) levels. We investigated the clinicopathological features associated with each confidence level.

RESULTS

The HEEs' evaluations determined the presence of DL in 99%, irregular MSP in 96%, and irregular MVP in 96%, and the LEEs' evaluations determined the presence of DL in 98%, irregular MSP in 95%, and irregular MVP in 95% of the EGCs. When DL was present, HC levels in the Helicobacter pylori- (H. pylori-) eradicated group and noneradicated group were evident in 65% and 89%, a difference that was significant (p < 0.001).

CONCLUSIONS

In the diagnosis of EGC with ME-BLI, the VS classification system with ME-NBI can be applied, but identifying the DL after H. pylori was difficult.

Endoscopic Management of Early Gastric Adenocarcinoma and Preinvasive Gastric Lesions

Early gastric cancer (ECG) can be difficult to diagnose endoscopically. Endoscopists should be familiar with subtle changes and endoscopic features of EGC. Chromoendoscopy and image-enhanced endoscopy improve diagnostic accuracy and facilitate endoscopic resection. Endoscopic submucosal dissection is a preferred endoscopic technique for resection of EGC and offers a comparable overall survival to surgical resection. Endoscopic management of benign gastric epithelial polyps (fundic gland polyps, hyperplastic polyps, and gastric adenoma) depends on patient symptomatology, patient's comorbidities (eg, familial syndromes), lesions' characteristics, and risk of malignant transformation. This article provides an overview of endoscopic management of EGC and common premalignant gastric lesions.

Acetic acid chromoendoscopy for determining the extent of gastric intestinal metaplasia

BACKGROUND AND AIMS

The diagnosis of gastric intestinal metaplasia (IM) is currently performed by histologic assessment of multiple endoscopic biopsies, methylene blue chromoendoscopy, or narrow-band imaging with magnification. However, practical and readily available methods are lacking. We assessed the diagnostic accuracy and reproducibility of acetic acid chromoendoscopy (AAC) for determining the extent of gastric IM.

METHODS

One hundred twenty-six participants were enrolled. The participants underwent screening EGD with 1.5% acetic acid instillation for the detection of acetowhite reaction. Subsequently, targeted biopsies were performed at the 5 standard intra-gastric locations of the updated Sydney system. The accuracy of AAC was calculated using the histology results as a reference. Two endoscopists, each of whom was blinded to the other's result, determined the presence or absence of acetowhite reaction.

RESULTS

The overall diagnostic accuracy of AAC was 89.0%, and the sensitivity and specificity were 77.6% and 94.4%, respectively. The specificity for the gastric body was >94%. The proportion of extensive IM, a strong risk factor for gastric cancer, increased from 0.9% to 18.1% when AAC was used instead of conventional EGD alone (P < .001). Endoscopically determined atrophy had a negative effect on the diagnosis of AAC (odds ratio, 3.012; 95% confidence interval, 1.625-5.583). There was substantial inter- and intra-observer agreement.

CONCLUSIONS

AAC is a valid and reproducible tool for determining the extent of gastric IM and may serve as a practical method of identifying populations at high risk of gastric cancer. (Clinical trial registration number: NCT01499576.).

Acetic Acid Enhanced Narrow Band Imaging for the Diagnosis of Gastric Intestinal Metaplasia

Gastric intestinal metaplasia (GIM) is a precancerous lesion of the stomach. The detection of GIM using conventional white-light endoscopy (WLE) is difficult. In this study, we determined whether acetic acid-enhanced narrow band imaging (AA-NBI) improves the detection of GIM. A consecutive cohort of 132 individuals aged 40 years or older was subjected to upper gastrointestinal endoscopy using WLE, NBI and AA-NBI. The ability of the three methods to diagnose GIM in patients was compared. Histological assessment (per-patient and per-biopsy) was used for the accuracy assessment. Sixty-six (50.0%) out of the 132 individuals examined were found to have GIM, of which 44 (66.7%) were diagnosed correctly by NBI (sensitivity 66.7% and specificity 68.2%) and 58 (87.9%) were correctly identified by AA–NBI (sensitivity 87.9% and specificity 68.2%), as compared to only 22 (33.3%) by WLE (sensitivity 33.3% and specificity 28.8%). Therefore, the sensitivity of AA–NBI in the diagnosis of GIM was significantly higher than NBI (p<0.05) and WLE (p < 0.001). Our study indicates that AA-NBI can improve the accuracy of endoscopy-targeted biopsies for GIM.

Evidence based review of the impact of image enhanced endoscopy in the diagnosis of gastric disorders

Gastric cancer is the third most common cause of cancer-related death. Advanced stages of gastric cancers generally have grim prognosis. But, good prognosis can be achieved if such cancers are detected, diagnosed and resected at early stages. However, early gastric cancers and its precursors often produce only subtle mucosal changes and therefore quite commonly remain elusive at the conventional examination with white light endoscopy. Image-enhanced endoscopy makes mucosal lesions more conspicuous and can therefore potentially yield earlier and more accurate diagnoses. Recent years have seen growing work of research in support of various types of image enhanced endoscopy (IEE) techniques (e.g., dye-chromoendoscopy; magnification endoscopy; narrow-band imaging; flexible spectral imaging color enhancement; and I-SCAN) for a variety of gastric pathologies. In this review, we will examine the evidence for the utilization of various IEE techniques in the diagnosis of gastric disorders.

How to improve endoscopic diagnosis of early gastric cancer?

Gastric cancer is the third leading cause of cancer death worldwide. The detection of early-stage gastric neoplastic lesions may improve survival. The gold standard for diagnosing gastric cancer remains endoscopy and histology of biopsy specimens. On one hand, we should administer the optimum preparation to patients, including an antiperistaltic agent. On the other hand, in order to detect the entire stomach, we need to follow a standardized protocol, and we should be aware of the diagnostic criteria for a suspicious lesion. Chromoendoscopy, narrow band imaging and magnifying endoscopy are promising image-enhanced endoscopic techniques for characterization. The criteria for diagnosing a cancerous lesion by narrow-band imaging with magnifying endoscopy are as follows: irregular microvascular pattern with a demarcation line or irregular microsurface pattern with a demarcation line. This paper gives a brief review of these methods.

Molecular endoscopy for targeted imaging in the digestive tract

Endoscopy uses optical imaging methods to investigate tissue in a non-destructive manner with high resolution over a broad range of wavelengths, thus providing a powerful tool to rapidly visualise mucosal surfaces in the digestive tract. Molecular imaging is an important advancement that has been clinically demonstrated for early cancer detection and guidance of therapy. With this approach, imaging can be used to observe expression patterns of molecular targets to improve understanding of key biological mechanisms that drive disease progression. Prototype devices that collect fluorescence for wide-field or microscopic images have been developed. Several targeting moieties, including enzyme-activatable probes, antibodies, peptides, and lectins, have been administered in preclinical and clinical imaging studies in vivo. These emerging technologies provide useful approaches to study molecular events in different signalling pathways, producing insights that could lead to improved interventions to prevent and treat gastrointestinal diseases. In this Review, we introduce the basic concepts that form the foundation for development of molecular endoscopy and summarise key results from preclinical and clinical studies.

Meta-analysis: The diagnostic efficacy of chromoendoscopy for early gastric cancer and premalignant gastric lesions

BACKGROUND AND AIM

Chromoendoscopy (CE) is widely used in the diagnosis of early gastric cancer (EGC) and premalignant gastric lesions (PGLs). We conducted a meta-analysis to evaluate the diagnostic efficacy of CE for EGC and PGLs.

METHODS

We searched PubMed/MEDLINE, EMBASE, and the Cochrane library to identify all eligible studies according to inclusion and exclusion standards. Publication bias was tested using Funnel plots and Egger's test. The possible sources of the heterogeneity were explored by performing a meta-regression analysis. Heterogeneity was assessed by the Q test and I(2) statistic.

RESULTS

Ten studies met the inclusion standards, including a total of 699 patients and 902 lesions. The pooled sensitivity, specificity, and area under the curve of CE were 0.90 (95% confidence interval, 0.87-0.92), 0.82 (95% confidence interval, 0.79-0.86), and 0.9464, respectively. In subgroup analysis of diagnostic accuracy, CE showed higher accuracy versus standard white light endoscopy for EGC (P = 0.005) and PGLs (P = 0.001).

CONCLUSION

Chromoendoscopy seems to have a high diagnostic efficacy and improve the detection of EGC and PGLs compared with standard white light endoscopy.

Useful condition of chromoendoscopy with indigo carmine and acetic acid for identifying a demarcation line prior to endoscopic submucosal dissection for early gastric cancer

Background

Identifying a precise demarcation line (DL) is indispensable for pathological complete en bloc endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). We evaluated the useful condition of chromoendoscopy with indigo carmine and acetic acid for marking dots around lesions before ESD for EGC.

Methods

We examined 98 consecutive patients with 109 intramucosal EGCs (mean diameter, 17.8 ± 12.4 mm; main histologic type, 96 intestinal and 13 diffuse) resected by en bloc ESD after chromoendoscopy with indigo carmine and acetic acid between December 2012 and February 2014. The DL was identified by this technique just before ESD (mean chromoendoscopy observation time, 71.6 s); subsequently, marking dots were placed around the EGC. EGCs were classified into two groups: useful for identifying the DL or useless. Clinicopathological characteristics and clinical outcomes were evaluated in each group.

Results

Forty-two of the 109 cases (38.5 %) were determined useful for chromoendoscopy with indigo carmine and acetic acid. Multivariate analysis with logistic regression showed that macroscopic type (protruded or flat elevated-type) and atrophic border (the oral side of tumor) were independently associated with the usefulness of chromoendoscopy using indigo carmine and acetic acid for identifying the DL of EGCs (P < 0.05). The histologically positive horizontal margin after ESD was 0 % (0/42) in useful cases, and 7.5 % (5/67) in useless cases.

Conclusions

Before ESD, chromoendoscopy with indigo carmine and acetic acid can be used for creating precise markings in protruded or flat elevated-type EGC or at the atrophic border on the oral side of EGCs.

Radiofrequency ablation for low-grade dysplasia in Barrett's esophagus

PURPOSE OF REVIEW

The diagnosis and management of low-grade dysplasia (LGD) in Barrett's esophagus continue to evolve and vary in practice. Radiofrequency ablation (RFA) is now an acceptable option for the treatment of LGD. Therefore, the purpose of this review article is to present current literature on the diagnosis and management of LGD, and to explore when to optimally pursue RFA for the treatment of LGD.

RECENT FINDINGS

The challenge of the management of LGD begins with its diagnosis. Because of high interobserver variability among pathologists in the diagnosis of dysplasia, it is recommended that an expert gastrointestinal pathologist confirms the diagnosis of LGD. Endoscopic mucosal resection is indicated to remove visible lesions in the setting of dysplasia to obtain an accurate diagnosis, especially regarding T staging. Management options include intense surveillance and endoscopic eradication therapy. RFA provides a reasonable method to eradicate flat Barrett's mucosa. Endoscopic eradication of confirmed LGD has been demonstrated to reduce the risk of progression to esophageal cancer. Additional data about the risk factors associated with progression, and the benefits and risks of treatment are discussed, and can be incorporated in patient counseling and decision making.

SUMMARY

Endoscopic eradication therapy with RFA may be an appropriate treatment option for LGD in Barrett's esophagus after the benefits and risks have been discussed in detail with the patient.

Magnifying endoscopy with narrow-band imaging is more accurate for determination of horizontal extent of early gastric cancers than chromoendoscopy

BACKGROUND AND STUDY AIMS

Although magnifying endoscopy with narrow-band imaging (ME-NBI) is reported to be useful for delineating the horizontal extent of early gastric cancers (EGCs), there are few reports which have objectively demonstrated the superiority of ME-NBI over chromoendoscopy with indigo carmine for this purpose. We conducted an exploratory comparison of the diagnostic accuracy of both modalities for the delineation of EGCs using prospectively collected data, and clarified the clinicopathological features related to inaccurate evaluation of the horizontal extent of EGCs.

PATIENTS AND METHODS

EGCs were assigned to the oral narrow-band imaging (O-NBI) group or the oral chromoendoscopy (O-CE) group before endoscopic submucosal dissection (ESD). The oral border was observed according to assignment, and the anal border with the other modality. The horizontal extent of the tumor was evaluated by each modality and a marking dot was placed on the visible delineation line. After ESD, the marking dots were identified pathologically and defined as "accurate evaluation" if they were located within 1 mm of the pathological tumor border. We compared the rate of accurate evaluation of ME-NBI and chromoendoscopy, and analyzed the clinicopathological features related to inaccurate evaluation.

RESULTS

A total of 113 marking dots evaluated by ME-NBI and 116 evaluated by chromoendoscopy were analyzed. The rate of accurate evaluation by ME-NBI was significantly higher than that by chromoendoscopy (89.4 % vs 75.9 %, P = 0.0071). The EGCs with flat borders and large EGCs were significantly related to inaccurate evaluation using ME-NBI. There were no significant factors related to inaccurate evaluation with chromoendoscopy.

CONCLUSIONS

The accurate evaluation rate of the horizontal extent of EGCs by ME-NBI is significantly higher than that by chromoendoscopy.

STUDY REGISTRATION

UMIN000007641.

Detection and Management of Early Gastric Cancer

OPINION STATEMENT

Early gastric cancer (EGC), defined as being confined to the submucosa, is a curable condition. In recent years, endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have been widely applied to subgroups of mucosal cancers, thereby avoiding the burden of operation while preserving gastric function. However, it can be difficult to identify mucosal cancers, which often evade detection due to their flat shapes without ulceration. Proper preparation to clean the mucosal surface, detailed systematic observation of the entire stomach, and the use of high-resolution systems for both endoscopies equipped with image-enhanced modality and monitors would facilitate the detection of such lesions. It is also critical to evaluate the resected specimen to confirm completeness of resection (tumor-free lateral and vertical margins as well as the absence of lymphatic and vascular invasion). If the resection is incomplete, further treatment is usually recommended-further endoscopic resection for patients with positive lateral margins or surgery for patients with positive vertical margins or with lymphatic or vascular involvement. The five-year survival for endoscopically resected EGC is excellent-and comparable to that of surgical therapy. Since most gastric cancers are caused by Helicobacter pylori, this infection should be tested for routinely. If a patient is H. pylori-positive, eradication is recommended, as heterotopic, metachronous recurrence of EGC is subsequently reduced. Importantly, basic principles for early diagnosis and endoscopic treatment of EGC can be applied to neoplasms arising in other parts of the gut, such as the esophagus and colon, and would be beneficial for patients through preserving organ function and minimizing operative intervention.

[Usefulness of systematic chromoendoscopy with a double dye staining technique for the detection of dysplasia in patients with premalignant gastric lesions]

INTRODUCTION

Premalignant gastric lesions have an increased risk to develop gastric cancer.

OBJECTIVE

To evaluate the usefulness of systematic endoscopy that includes chromoendoscopy with a double dye staining technique for the detection of dysplasia in patients with premalignant gastric lesions.

PATIENTS AND METHODS

This longitudinal, prospective study was performed in patients with gastric atrophy, intestinal metaplasia or dysplasia who were referred for endoscopy less than 6 months after the initial diagnosis. The second endoscopy was performed in three phases: phase 1, exhaustive and systematic review of the mucosa with photographic documentation and biopsies of suspicious areas; phase 2, chromoendoscopy with a double dye staining technique using acetic acid 1.2% and indigo carmine 0.5%; phase 3, topographic mapping and random biopsies.

RESULTS

A total of 50 patients were included. Nine (18%) had atrophic gastritis, 38 (76%) had intestinal metaplasia, and 3 (6%) had low-grade dysplasia. Systematic endoscopy with chromoendoscopy using a double dye staining technique detected more patients with dysplasia (9 versus 3, p<.05), and a larger number of biopsies with the diagnosis of dysplasia were obtained. This occurred for visible (6 vs. 0, p<.05) and non-visible lesions (6 vs. 3, p=NS). In one patient, initial low-grade dysplasia was not detected again in the systematic endoscopy, giving a global endoscopic performance for the detection of lesions of 92%.

CONCLUSIONS

Patients with premalignant gastric lesions have synchronous lesions with greater histological severity, which are detected when systematic endoscopy is conducted with indigo carmine dye added to acetic acid.

Endoscopic prediction of tumor margin and invasive depth in early gastric cancer

Gastric cancer (GC) is the fifth most common cancer and the third leading cause of cancer-related deaths in the world. The prognosis of GC is clearly associated with the tumor stage, with a 5-year overall survival rate for early gastric cancer (EGC) exceeding 90%, which is significantly higher than that of advanced gastric cancer. Endoscopic resection, including endoscopic mucosal resection and endoscopic submucosal dissection, has been adopted in recent decades as the first treatment option of EGC in many countries for its minimal invasion and high curative rate. However, the horizontal and vertical margins are related to the curative resection of EGC and the prognosis of patients. Thus the accurate prediction of the tumor boundary and its invasive depth before treatment counts for much in planning the most appropriate treatment strategy and promising curative resection. To date, various endoscopic techniques have been identified to play a role in pretreatment evaluation, such as white light endoscopy, chromoendoscopy, narrow band imaging and endoscopic ultrasonography. This article aimed to summarize the diagnostic methods, applications and limitations of these different endoscopic techniques for identifying tumor horizontal and vertical margins in EGC, helping to increase preoperative evaluation of capabilities and to improve the curative resection rate of EGC.

Diagnosis of early gastric cancer using narrow band imaging and acetic acid

AIM: To determine whether the endoscopic findings of depressed-type early gastric cancers (EGCs) could precisely predict the histological type.

METHODS: Ninety depressed-type EGCs in 72 patients were macroscopically and histologically identified. We evaluated the microvascular (MV) and mucosal surface (MS) patterns of depressed-type EGCs using magnifying endoscopy (ME) with narrow-band imaging (NBI) (NBI-ME) and ME enhanced by 1.5% acetic acid, respectively. First, depressed-type EGCs were classified according to MV pattern by NBI-ME. Subsequently, EGCs unclassified by MV pattern were classified according to MS pattern by enhanced ME (EME) images obtained from the same angle.

RESULTS: We classified the depressed-type EGCs into the following 2 MV patterns using NBI-ME: a fine-network pattern that indicated differentiated adenocarcinoma (25/25, 100%) and a corkscrew pattern that likely indicated undifferentiated adenocarcinoma (18/23, 78.3%). However, 42 of the 90 (46.7%) lesions could not be classified into MV patterns by NBI-ME. These unclassified lesions were then evaluated for MS patterns using EME, which classified 33 (81.0%) lesions as MS patterns, diagnosed as differentiated adenocarcinoma. As a result, 76 of the 90 (84.4%) lesions were matched with histological diagnoses using a combination of NBI-ME and EME.

CONCLUSION: A combination of NBI-ME and EME was useful in predicting the histological type of depressed-type EGC.

In vivo molecular imaging of gastric cancer in human-murine xenograft models with confocal laser endomicroscopy using a tumor vascular homing peptide

The early detection of premalignant lesions and cancers are very important for improving the survival of patients with gastric malignancies. Confocal laser endomicroscopy (CLE) is a novel imaging tool for achieving real-time microscopy during the ongoing endoscopy at subcellular resolution. In the present study, to evaluate the feasibility of real-time molecular imaging of GEBP11 by CLE in gastric cancer, CLE was performed on two types of tumor-bearing mice models, as well as surgical specimens of patients with gastric cancer, after the application of GEBP11. A whole-body fluorescent imaging device was first used to screen for the strongest specific fluorescent signal in xenograft models. Next, the tumor sites, as well as human tissues, were scanned with CLE. After this, targeted specimens were obtained for fluorescence microscopy and histology. We confirmed that GEBP11 could specifically bind to co-HUVECs by means of CLE in cell experiments. Thereafter, a specific signal was observed in both subcutaneous and orthotopic xenograft models in vivo after the injection of FITC-GEBP11 via tail vein, whereas the group injected with FITC-URP showed no fluorescent signals. In human tissues, a specific signal of GEBP11 was observed in 26/28 neoplastic specimens and in 8/28 samples of non-neoplastic specimens from the patients (p < 0.01). The findings from ex vivo immunofluorescence microscopy of cryostat sections correlated well with that obtained by CLE. These findings indicate that the peptide, GEBP11, might be a potential candidate for the molecular imaging of gastric cancer.

Prospective cohort study assessing outcomes of patients from families fulfilling criteria for hereditary diffuse gastric cancer undergoing endoscopic surveillance

BACKGROUND

Prophylactic total gastrectomy is performed in hereditary diffuse gastric cancer (HDGC) patients carrying the CDH1 mutation because endoscopic surveillance often fails to detect microscopic disease.

OBJECTIVE

The aim of this study was to determine the natural history and outcomes of patients with HDGC undergoing endoscopy.

DESIGN

Prospective, cohort observational study.

SETTINGS

Tertiary referral center.

PATIENTS

Patients fulfilling criteria for HDGC who opted to undergo endoscopy.

INTERVENTION

Research surveillance program using high-resolution white-light endoscopy with autofluorescence and narrow-band imaging combined with targeted and multiple random biopsies assessed by an expert histopathologist for the presence of signet ring cell carcinoma.

MAIN OUTCOME MEASUREMENTS

The primary endpoint was the endoscopic yield of microscopic signet ring cell carcinoma according to patient mutation status and subsequent decision to undergo surgery. The secondary endpoint was the additional yield of targeted biopsies compared with random biopsies.

RESULTS

Between September 2007 and March 2013, 29 patients from 17 families underwent 70 surveillance endoscopies. Signet ring cell carcinoma foci were identified in 14 of 22 (63.6%) patients with confirmed CDH1 germline mutations and 2 of 7 (28.6%) with no pathogenic mutation identified. Eleven of 16 (9 CDH1-positive) patients proceeded to gastrectomy in a median 5.7 months. Five patients delayed surgery. In 1 patient, advanced gastric cancer developed 40.2 months after the first endoscopic findings.

LIMITATIONS

No control group.

CONCLUSIONS

Careful white-light examination with targeted and random biopsies combined with detailed histopathology can identify early lesions and help to inform decision making with regard to gastrectomy. Autofluorescence and narrow-band imaging are of limited utility. Delaying gastrectomy in individuals with signet ring cell carcinoma foci carries a high risk and has to be weighed carefully.

Proposal of the surgical options for primary tumor control during sentinel node navigation surgery based on the discrepancy between preoperative and postoperative early gastric cancer diagnoses

BACKGROUND

There is no consensus on the optimal method of primary tumor control, determined by preoperative clinical factors, during sentinel node (SN) navigation surgery for early gastric cancer (EGC). In this study, we investigated the accuracy of clinical diagnosis based on preoperative examination in patients with EGC and proposed surgical options for primary tumor control during SN navigation surgery.

METHODS

We analyzed 815 patients with clinical stage IA gastric cancer who underwent gastrectomy at the National Cancer Center in Korea between March 2001 and February 2011. The clinical stage was determined by endoscopy, endoscopic ultrasonography, and abdominal computed tomography.

RESULTS

The preoperative assessment of tumor depth and tumor size was accurate in 57.5 and 70.8 % of patients, respectively. Tumor depth and size were underestimated in 8 and 25.3 % of patients. The overall accuracy of histologic diagnosis by endoscopic biopsy was 87.2 %. Of those tumors diagnosed preoperatively as differentiated, 20.5 % revealed mixed histology of undifferentiated type.

CONCLUSIONS

The recommendation for SN biopsy may be limited to tumors sized 3 cm or smaller to avoid positive lateral margins and to minimize the risk of skip metastases. Endoscopic resection may safely be applied to small mucosal cancers, but other surgical options should be employed for undifferentiated large mucosal lesions, given their tendency for diffuse invasion. Full-thickness resection is preferable for submucosal cancers, to secure clear vertical margins.

Endoscopic mucosal imaging of gastrointestinal neoplasia in 2013

The holy grail of gastrointestinal endoscopy consists of the detection, in vivo characterization, and endoscopic removal of early or premalignant mucosal lesions. While our ability to achieve this goal has improved substantially since the development of the modern video-endoscope, inadequate visual inspection, errors of interpretation, and lesion subtlety all contribute to the continued suboptimal detection and assessment of early neoplasia. A myriad of new technologies has thus emerged that may help resolve these shortcomings; high magnification endoscopes, as well as the techniques of dye-based and virtual chromoendoscopy, are now widely available, while confocal laser endomicroscopy and endocystoscopy, optical coherence tomography, and autofluorescence imaging are generally applicable only in a research setting. Such technologies can be broadly categorized according to whether they potentially afford endoscopists improved detection, or real-time characterization, of mucosal lesions. Enhanced detection of otherwise "invisible" lesions, such as a flat area of intramucosal adenocarcinoma within Barrett's esophagus, carries the potential of an endoscopic cure prior to the development into a more advanced or metastatic disease. The ability to characterize a lesion to achieve an in vivo diagnosis, such as a colonic polyp, potentially affords endoscopists the ability to decide which lesions require removal and which can be safely left behind or discarded without histological assessment. Furthermore targeted biopsies, such as in the surveillance of chronic colitis, may prove to be more accurate and efficacious than the current protocol of random biopsies. An important caveat in the discussion of developing technologies in early cancer detection is the fundamental importance of a health-care system that promotes screening programs to recruit at-risk individuals. The ideal tool to optimize the use of endoscopy in population screening would be a panel of reliable biomarkers (blood, stool, or urine) that could effectively select a high-risk group, thus reducing the indiscriminate use of an expensive technology. The following review summarizes the current endoscopic imaging techniques available, and in development, for the early identification of gastrointestinal neoplasia.

Flexible imaging color enhancement improves visibility of transnasal endoscopic images in diagnosing esophageal varices: a multicenter prospective blinded study

OBJECTIVE

To clarify the usefulness of transnasal esophagogastroduodenoscope (N-EGD) with all flexible imaging color enhancement (FICE) patterns (0-9) for the diagnosis of esophageal varices (EV).

METHODS

A total of 50 patients with EV were examined during the same period by N-EGD without sedation and by peroral endoscopy (O-EGD) with sedation. The visibility of treatment scars, microvessels, recurrent EV and red color sign (RCS) were measured. Visibility was evaluated by five blinded observers (poor-good: 0-10), and the effect of both endoscopic examinations on the cardiorespiratory function of the patients was measured.

RESULTS

The image scores for O-EGD and N-EGD with ordinary mode and N-EGD with FICE were 7.3 ± 1.2, 6.1 ± 1.0 and 6.9 ± 1.0 for treatment scars; 7.2 ± 1.4, 6.2 ± 1.2 and 7.3 ± 1.0 for microvessels; 7.2 ± 1.2, 6.1 ± 1.0 and 7.1 ± 1.0 for recurrent EV and 7.2 ± 1.3, 6.1 ± 1.3, and 7.2 ± 1.2 for RCS, respectively (intraclass correlation coefficients > 0.6). When FICE patterns 2, 6 and 9 were used, visibility was much improved. Ten minutes after insertion, the double product values in the N-EGD with the FICE group were significantly better (P < 0.05).

CONCLUSIONS

N-EGD with FICE is very useful for the diagnosis of EV and can improve the visibility of N-EGD on each lesion to the same level as that of O-EGD. N-EGD with FICE does not require sedation and may reduce the risk of hepatic encephalopathy.

Molecular in vivo imaging of gastric cancer in a human-murine xenograft model: targeting epidermal growth factor receptor

BACKGROUND

The prognosis of gastric cancer depends on early diagnosis. Targeted therapies against epidermal growth factor receptors (EGFRs) are currently emerging for the treatment of gastric cancer.

OBJECTIVE

To specifically visualize gastric cancer by using monoclonal antibodies targeting EGFR1 as molecular probes for in vivo molecular confocal laser endomicroscopy (mCLE) in a human-murine xenograft model.

DESIGN

Prospective in vivo animal study.

SETTING

Animal laboratory.

INTERVENTIONS

Human gastric carcinoma xenografts were examined in 26 nude mice by using mCLE after injection of fluorescently labeled antibodies. Nine mice received low-dose anti-EGFR1 antibodies, 7 mice cetuximab, and 7 control mice isotype antibodies. Three mice were screened for autofluorescence without injection. Macroscopic fluorescence was evaluated in 2 additional mice.

MAIN OUTCOME MEASUREMENTS

Molecular imaging of gastric cancer with confocal laser endomicroscopy.

RESULTS

Fluorescence intensity in the anti-EGFR1 (P = .0145) and cetuximab group (P = .0047) was significantly higher than in isotype control mice. The same protocol allowed macroscopic fluorescence detection of tumor xenografts.

LIMITATIONS

Animal model.

CONCLUSIONS

In vivo microscopic and macroscopic molecular imaging of gastric cancer is feasible in a human-murine xenograft model with both diagnostic and therapeutic antibodies targeting EGFR1. In perspective, mCLE could help diagnose and molecularly characterize gastric cancer during ongoing gastroscopy and may even assist in the prediction of response to therapy.

Helpfulness of the combination of acetic acid and FICE in the detection of Barrett's epithelium and Barrett's associated neoplasias

AIM: To investigate the mucosal morphology in Barrett’s oesophagus by chromo and magnifying endoscopy.

METHODS: A prospective pilot study at a tertiary medical centre was conducted to evaluate the use of acetic acid pulverisation combined with virtual chromoendoscopy using Fujinon intelligent chromoendoscopy (FICE) for semiological characterization of the mucosal morphology in Barrett’s oesophagus and its neoplastic complications. Upper endoscopy using high definition white light, 2% acid acetic pulverisation and FICE with high definition videoendoscopy were performed in 20 patients including 18 patients who presented with aspects of Barrett’s oesophagus at endoscopy examination. Two patients used as controls had normal endoscopy and histological results. Prospectively, videos were watched blind from histological results by three trained FICE technique endoscopists.

RESULTS: The videos of patients with high-grade dysplasia showed an irregular mucosal pattern in 14% using high definition white light endoscopy and in 100% using acid acetic-FICE combined. Videos did not identify irregular vascular patterns using high definition white light endoscopy, while acid acetic-FICE combined visualised one in 86% of cases.

CONCLUSION: Combined acetic acid and FICE is a promising method for screening high-grade dysplasia and early cancer in Barrett’s oesophagus.

Frozen Section Biopsy to Evaluation of Obscure Lateral Resection Margins during Gastric Endoscopic Submucosal Dissection for Early Gastric Cancer

Purpose

To determine the diagnostic utility of a frozen section biopsy in patients undergoing endoscopic submucosal dissection (ESD) for early gastric neoplasms with obscure margins even with chromoendoscopy using acetic acid and indigo carmine (AI chromoendoscopy).

Materials and Methods

The lateral spread of early gastric neoplasms was unclear even following AI chromoendoscopy in 38 patients who underwent ESD between June 2007 and May 2011. Frozen section biopsies were obtained by agreement of the degree of lateral spread between two endoscopists. Thus, frozen section biopsies were obtained from 23 patients (FBx group) and not in the other 15 patients (AI group).

Results

No significant differences were observed for size, histology, invasive depth, and location of lesions between the AI and FBx groups. No false positive or false negative results were observed in the frozen section diagnoses. Adenocarcinoma was revealed in three patients and tubular adenoma in one, thereby changing the delineation of lesion extent and achieving free lateral margins. The rates of free lateral resection margins and curative resection were significantly higher in the FBx group than those in the AI group.

Conclusions

Frozen section biopsy can help endoscopists perform more safe and accurate ESD in patients with early gastric neoplasm.

Technical issues and new devices of ESD of early gastric cancer

Endoscopic submucosal dissection (ESD) is a highly refined technique compared to conventional endoscopic mucosal resection. It enables complete resection of early gastric cancer (EGC) which has no possibility of lymph node metastasis. Indication for ESD of EGC generally entails early gastric cancer confined to the mucosa with well differentiated histology, though there are clinically suitable expanded criteria. As ESD requires specific skill and expertise, endoscopists need to be familiarized with basic methods and the use of special devices. The essence of the technique is to dissect the submucosal layer with direct vision and maintain the cutting plane above the underlying proper muscle layer. Although there are some differences in the detailed technical aspect, the cardinal method of ESD is now well established and standardized. Furthermore, research and development of new ESD devices that render more efficient, safe ESD are still in progress to improve the overall result of ESD on early gastric cancer.

Factors related to lateral margin positivity for cancer in gastric specimens of endoscopic submucosal dissection

BACKGROUND

With the widespread use of endoscopic submucosal dissection (ESD), more large early gastric cancers (EGC) have become candidates for endoscopic resection. A precise diagnosis of the extent of cancer is indispensable to obtain R0 resection. The aim of the present study was to clarify the factors related to lateral margin positivity for cancer in specimens resected by ESD for EGC.

METHODS

Among 1549 EGC treated by ESD during September 2002 to December 2008, lesions that were resected in an en-bloc fashion and resulted in a pathological diagnosis of lateral margin positive (LM+) for cancer, were extracted. The reason for LM+ and pathological characteristics of the lesions were studied and compared to lesions successfully resected with margins negative for cancer.

RESULTS

There were three types of lesion that resulted in LM+ resection: lesions with a flat spreading area, lesions with an unexpected nearby lesion, and lesions with lateral extension beneath a non-cancerous mucosa. Compared to lesions resected with margins negative for cancer, diameter of the tumor, recurrent-type cancer, submucosal cancer, and undifferentiated-type cancer were factors significantly related to LM+ resection.

CONCLUSION

Other than misdiagnosing a small portion of cancer extension, lateral margin positivity for cancer by ESD could result from a neighboring lesion and an unexpected lateral submucosal cancer extension. To avoid LM+ resection of EGC by ESD, one should be careful of unexpected lateral extension and simultaneous multi-lesions.

Confocal laser endomicroscopy for in vivo diagnosis of gastric intraepithelial neoplasia: a feasibility study

BACKGROUND

Confocal laser endomicroscopy (CLE) is a novel endoscopic modality that allows subsurface analysis of the gastric mucosa during ongoing endoscopy. Several studies have reported that this technique is of value in the diagnosis of premalignant lesions in the GI tract, but as yet no investigations have reported its application in the analysis of gastric intraepithelial neoplasia (GIN).

OBJECTIVE

To assess the feasibility of CLE for the identification and grading of GIN.

DESIGN

Prospective double-blind feasibility study.

SETTING

Qilu Hospital, Shandong University, Jinan, China.

PATIENTS

CLE images of 33 patients were first evaluated to establish the diagnostic criteria for gastric lesions. Eligible patients were then prospectively investigated by CLE using the newly established criteria.

INTERVENTIONS

All endoscopically suspicious lesions were examined by CLE, and CLE diagnoses were compared with corresponding histopathologic results.

MAIN OUTCOME MEASUREMENTS

Sensitivity, specificity, and positive and negative likelihood ratios of CLE diagnosis of biopsy-proven intraepithelial neoplasia by per-lesion analysis.

RESULTS

The sensitivity, specificity, and positive and negative likelihood ratios of CLE diagnosis of GIN were 77.8%, 81.8%, 4.28, and 0.27, respectively. The mean κ value for interobserver agreement for the diagnosis of GIN was 0.70 among endoscopists and 0.71 between endoscopist and GI pathologist. Intraepithelial neoplasia score ≥5 differentiated high-grade from low-grade intraepithelial neoplasia with a sensitivity of 66.7% and a specificity of 88.0%.

LIMITATIONS

Nonrandomized single-center study, limited number of patients.

CONCLUSIONS

CLE is an acceptable and potentially useful technology for the identification and grading of GIN in vivo. The diagnostic accuracy needs to be improved.

Acetic acid-indigo carmine chromoendoscopy for delineating early gastric cancers: its usefulness according to histological type

Background

Endoscopic treatments, such as endoscopic submucosal dissection (ESD) and laparoscopic gastrectomy, are increasingly used to treat a subset of patients with early gastric cancer (EGC). To achieve successful outcomes, it is very important to accurately determine the lateral extent of the tumor. Therefore, we investigated the diagnostic performance of chromoendoscopy using indigo carmine dye added to acetic acid (AI chromoendoscopy) in delineating differentiated or undifferentiated adenocarcinomas in patients with EGC.

Methods

We prospectively included 151 lesions of 141 patients that had an endoscopic diagnosis of EGC. All the lesions were examined by conventional endoscopy and AI chromoendoscopy before ESD or laparoscopic gastrectomy. The border clarification between the lesion and the normal mucosa was classified as distinct or indistinct before and after AI chromoendoscopy.

Results

The borders of the lesions were distinct in 66.9% (101/151) with conventional endoscopy and in 84.1% (127/151) with AI chromoendoscopy (P < 0.001). Compared with conventional endoscopy, AI chromoendoscopy clarified the border in a significantly higher percentage of differentiated adenocarcinomas (74/108 [68.5%] vs 97/108 [89.8%], respectively, P < 0.001). However, the border clarification rate for undifferentiated adenocarcinomas did not differ between conventional endoscopy and AI chromoendoscopy (27/43 [62.8%] vs 30/43 [70.0%], respectively, P = 0.494).

Conclusions

AI chromoendoscopy is useful in determining the lateral extent of EGCs. However, its usefulness is reduced in undifferentiated adenocarcinomas.

Risk factors for delayed bleeding after endoscopic submucosal dissection for gastric neoplasm

BACKGROUND

Delayed bleeding is one of the major complications of endoscopic submucosal dissection (ESD). The aim of this study is to determine the incidence rate and clinical factors associated with delayed bleeding, as well as the time interval between bleeding and ESD for gastric neoplasm.

METHODS

We investigated 647 lesions in 582 consecutive patients undergoing ESD for gastric neoplasm.

RESULTS

Delayed bleeding after ESD was evident in all 28 lesions from 28 patients (4.33% of all specimens, 4.81% of patients), and all achieved endoscopic hemostasis. Resected specimen width (≥40 mm) was the only significant factor associated with delayed bleeding on univariate and multivariate analysis. In early delayed bleeding (bleeding occurring on or before the fourth postoperative day), wide resected specimen and tumor location in the lower third of the stomach were significant risk factors. In late delayed bleeding (bleeding occurring after the fifth operative day), wide resected specimen, tumor location in the middle third of the stomach, hypertension, and high body mass index (≥25 kg/m(2)) were significant factors. Delayed bleeding in patients with tumors in the upper and middle third of the stomach (median 8.0 days; range 1-20 days) occurred significantly later as compared with patients who had tumors in the lower third (median 2.0 days; range 1-34 days).

CONCLUSIONS

Risk factors for delayed bleeding, and the probable underlying mechanism involved, differed depending on the time elapsed between surgery and the bleeding episode.