Usefulness of magnifying endoscopy in the diagnosis of early gastric cancer

Magnifying image-enhanced endoscopy-only mode boosted early cancer diagnostic efficiency: a multicenter randomized controlled trial

BACKGROUND AND AIMS

Magnifying image-enhanced endoscopy (MIEE) is an advanced endoscopy with image enhancement and magnification used in preoperative examination. However, its impact on the detection rate is unknown.

METHODS

We conducted an open-label, randomized, parallel (1:1:1), controlled trial in 6 hospitals in China. Patients were recruited between February 14, 2022 and July 30, 2022. Eligible patients were aged ≥18 years and undergoing gastroscopy in outpatient departments. Participants were randomly assigned to the MIEE-only mode (o-MIEE) group, white-light endoscopy-only mode (o-WLE) group, and MIEE when necessary mode (n-MIEE) group (initial WLE followed by switching to another endoscope with MIEE if necessary). Biopsy sampling of suspicious lesions of the lesser curvature of the gastric antrum was performed. Primary and secondary aims were to compare detection rates and positive predictive value (PPV) of early cancer and precancerous lesions in these 3 modes, respectively.

RESULTS

A total of 5100 recruited patients were randomly assigned to the o-MIEE (n = 1700), o-WLE (n = 1700), and n-MIEE (n = 1700) groups. In the o-MIEE, o-WLE, and n-MIEE groups, 29 (1.51%; 95% confidence interval [CI], 1.05-2.16), 4 (.21%; 95% CI, .08-.54), and 8 (.43%; 95% CI, .22-.85) early cancers were found, respectively (P < .001). The PPV for early cancer was higher in the o-MIEE group compared with the o-WLE and n-MIEE groups (63.04%, 33.33%, and 38.1%, respectively; P = .062). The same trend was seen for precancerous lesions (36.67%, 10.00%, and 21.74%, respectively).

CONCLUSIONS

The o-MIEE mode resulted in a significant improvement in diagnosing early upper GI cancer and precancerous lesions; thus, it could be used for opportunistic screening. (Clinical trial registration number: ChiCTR2200064174.).

Real-time use of artificial intelligence for diagnosing early gastric cancer by magnifying image-enhanced endoscopy: a multicenter diagnostic study (with videos)

BACKGROUND AND AIMS

Endoscopy is a pivotal method for detecting early gastric cancer (EGC). However, skill among endoscopists varies greatly. Here, we proposed a deep learning-based system named ENDOANGEL-ME to diagnose EGC in magnifying image-enhanced endoscopy (M-IEE).

METHODS

M-IEE images were retrospectively obtained from 6 hospitals in China, including 4667 images for training and validation, 1324 images for internal tests, and 4702 images for external tests. One hundred eighty-seven stored videos from 2 hospitals were used to evaluate the performance of ENDOANGEL-ME and endoscopists and to assess the effect of ENDOANGEL-ME on improving the performance of endoscopists. Prospective consecutive patients undergoing M-IEE were enrolled from August 17, 2020 to August 2, 2021 in Renmin Hospital of Wuhan University to assess the applicability of ENDOANGEL-ME in clinical practice.

RESULTS

A total of 3099 patients undergoing M-IEE were enrolled in this study. The diagnostic accuracy of ENDOANGEL-ME for diagnosing EGC was 88.44% and 90.49% in internal and external images, respectively. In 93 internal videos, ENDOANGEL-ME achieved an accuracy of 90.32% for diagnosing EGC, significantly superior to that of senior endoscopists (70.16% ± 8.78%). In 94 external videos, with the assistance of ENDOANGEL-ME, endoscopists showed improved accuracy and sensitivity (85.64% vs 80.32% and 82.03% vs 67.19%, respectively). In 194 prospective consecutive patients with 251 lesions, ENDOANGEL-ME achieved a sensitivity of 92.59% (25/27) and an accuracy of 83.67% (210/251) in real clinical practice.

CONCLUSIONS

This multicenter diagnostic study showed that ENDOANGEL-ME can be well applied in the clinical setting. (Clinical trial registration number: ChiCTR2000035116.).

A case of signet ring cell carcinoma and mucosa-associated lymphoid tissue lymphoma of the stomach diagnosed simultaneously via magnifying endoscopy with narrow-band imaging

We present the case of a 57-year-old woman who experienced 3 weeks of intermittent tarry stools and epigastric pain. She had a 25-year history of smoking and a 12-year history of heavy alcohol consumption but had discontinued both 12 years prior. Laboratory investigations revealed elevated anti-H. Pylori IgG antibody levels. Conventional upper gastrointestinal endoscopy revealed two lesions. Magnifying endoscopy with narrow-band imaging showed the characteristic appearance of a diffuse-type gastric cancer 0-IIc lesion with a demarcation line and abnormal vessels ("wavy micro-vessels" and a "cork-screw pattern"). There was also "ballooning" of the crypts and a "tree-like vessel appearance" in an "unstructured area" characteristic of gastric mucosa-associated lymphoid tissue lymphoma with ulceration. Accurate target biopsies were obtained. We performed a laparoscopic total gastrectomy with D1 lymphadenectomy. Pathological examination revealed poorly differentiated stage I adenocarcinoma of the stomach with features of signet ring cell carcinoma as well as stage I mucosa-associated lymphoid tissue lymphoma. In conclusion, we encountered a case of co-existing diffuse-type gastric cancer and gastric mucosa-associated lymphoid tissue lymphoma. Magnifying endoscopy with narrow-band imaging was effective for diagnosing these two co-existing tumors and resulted in the collection of adequate biopsy specimens allowing for an accurate pathological diagnosis and optimal treatment.

Guidelines for endoscopic submucosal dissection and endoscopic mucosal resection for early gastric cancer (second edition)

In response to the rapid and wide acceptance and use of endoscopic treatments for early gastric cancer, the Japan Gastroenterological Endoscopy Society, in collaboration with the Japanese Gastric Cancer Association, produced "Guidelines for Endoscopic Submucosal Dissection and Endoscopic Mucosal Resection for Early Gastric Cancer" in 2014, as a set of basic guidelines in accordance with the principles of evidence-based medicine. At the time, a number of statements had to be established by consensus (the lowest evidence level), as evidence levels remained low for many specific areas in this field. However, in recent years, the number of well-designed clinical studies has been increasing. Based on new findings, we have issued the revised second edition of the above guidelines that cover the present state of knowledge. These guidelines are divided into the following seven categories: indications, preoperative diagnosis, techniques, evaluation of curability, complications, long-term postoperative surveillance, and histology.

Guidelines for endoscopic diagnosis of early gastric cancer

The Japan Gastroenterological Endoscopy Society developed the Guideline for Endoscopic Diagnosis of Early Gastric Cancer based on scientific methods. Endoscopy for the diagnosis of early gastric cancer has been acknowledged as a useful and highly precise examination, and its use has become increasingly more common in recent years. However, the level of evidence in this field is low, and it is often necessary to determine recommendations based on expert consensus only. This clinical practice guideline consists of the following sections to provide the current guideline: [I] Risk stratification of gastric cancer before endoscopic examination, [II] Detection of early gastric cancer, [III] Qualitative diagnosis of early gastric cancer, [IV] Diagnosis to choose the therapeutic strategy for gastric cancer, [V] Risk stratification after endoscopic examination, and [VI] Surveillance of early gastric cancer.

Generation of magnifying endoscopic images of gastric neoplasms based on an all-in-focus algorithm

BACKGROUND AND AIM

Magnifying endoscopy is useful for diagnosis of early gastrointestinal neoplasms by visualizing microvascular (MV) and microsurface (MS) structures of the mucosa when combined with image-enhanced endoscopy. However, precise control of the endoscope is needed because the depth of focus is narrow and the target may move. These problems may be overcome by the all-in-focus (AIF) technique, which was developed in the engineering field. The aim of the study was to evaluate magnifying endoscopic image with AIF algorithm.

METHODS

Twenty gastric neoplasms were examined. Images were acquired at 80× magnification and converted to endoscopic images with an AIF algorithm (EI-AIF). The focus area and MV and MS patterns in the original image and the EI-AIF were compared on a 5-point Likert scale, where 5 indicates that the EI-AIF was superior. Intraclass correlation coefficients (ICCs) were used to assess the inter-evaluator reliability. An image quality measurement value was calculated for each image as an indicator of the degree of focus.

RESULTS

The scores for focus area, MV, and MS were 4.78 ± 0.45 (ICC = 0.63), 4.12 ± 0.76 (ICC = 0.70), and 4.72 ± 0.52 (ICC = 0.45), respectively, with the EI-AIF significantly superior for all three items (P < 0.05 by Student's t-test). ICCs for the focus area and MV were > 0.60, indicating strong inter-evaluator reliability. Image quality measurement was higher for the EI-AIF compared with the original image in every case.

CONCLUSIONS

Endoscopic observation with AIF algorithm gives a better image quality that allows easier evaluation of MV and MS patterns. This technique may resolve the difficulties with magnifying endoscopic observation.

Short-term outcomes of traction-assisted versus conventional endoscopic submucosal dissection for superficial gastrointestinal neoplasms: a systematic review and meta-analysis of randomized controlled studies

Background

In recent years, some traction-assisted approaches have been introduced to facilitate endoscopic submucosal dissection (ESD) procedures by reducing the procedure time and risks related to the procedure. However, the relative advantages of traction-assisted endoscopic submucosal dissection (T-ESD) are still being debated. This study aimed to assess the efficacy of T-ESD for the treatment of superficial gastrointestinal neoplasms.

Methods

We searched MEDLINE, Embase, and Cochrane library up to March 31, 2019 for randomized controlled trials (RCTs) comparing T-ESD and conventional endoscopic submucosal dissection (C-ESD) for superficial gastrointestinal neoplasms. The main endpoints are en bloc resection, complete resection, procedure time, perforation, and delayed bleeding. Pooled risk ratio (RR), Peto odds ratio (OR), and mean difference (MD) were calculated to compare T-ESD and C-ESD. This study is registered with PROSPERO, number CRD42018108135.

Results

A total of 7 RCTs with 1007 patients were included in this meta-analysis. There were no significant differences between the T-ESD and C-ESD groups in the pooled estimate of en bloc resection, complete resection, and delayed bleeding (RR = 1.00, 95% CI 0.99, 1.01, I² = 0%, P = 0.66; RR = 1.00, 95% CI 0.98, 1.03, I² = 0%, P = 0.81; OR = 0.95, 95% CI 0.48, 1.86, I² = 19%, P = 0.87,respectively). The pooled estimate indicated that the procedure time was significantly shorter in the T-ESD group (MD = − 16.19, 95% CI − 29.24, − 3.13, I² = 87%, P = 0.02) than in the C-ESD group. Compared to C-ESD, T-ESD was associated with lower incidence of perforation (OR = 0.32, 95% CI 0.11, 0.91, I² = 0%, P = 0.03).

Conclusions

T-ESD is a safe and effective treatment option with a low perforation rate and shorter procedure time than C-ESD for superficial gastrointestinal neoplasms. Future multi-center (including European populations), randomized controlled trials of larger sample size and long-term outcomes of T-ESD are required.

Advanced endoscopic methods in gastrointestinal diseases: a systematic review

Endoscopic imaging is the main method for detecting gastrointestinal diseases, which adversely affect human health. White light endoscopy (WLE) was the first method used for endoscopic examination and is still the preliminary step in the detection of gastrointestinal diseases during clinical examination. However, it cannot accurately diagnose gastrointestinal diseases owing to its poor correlation with histopathological diagnosis. In recent years, many advanced endoscopic methods have emerged to improve the detection accuracy by endoscopy. Chromoendoscopy (CE) enhances the contrast between normal and diseased tissues using biocompatible dye agents. Narrow band imaging (NBI) can improve the contrast between capillaries and submucosal vessels by changing the light source acting on the tissue using special filters to realize the visualization of the vascular structure. Flexible spectral imaging color enhancement (FICE) technique uses the reflectance spectrum estimation technique to obtain individual spectral images and reconstructs an enhanced image of the mucosal surface using three selected spectral images. The i-Scan technology takes advantage of the different reflective properties of normal and diseased tissues to obtain images, and enhances image contrast through post-processing algorithms. These abovementioned methods can be used to detect gastrointestinal diseases by observing the macroscopic structure of the digestive tract mucosa, but the ability of early cancer detection is limited with low resolution. However, based on the principle of confocal imaging, probe-based confocal laser endomicroscopy (pCLE) can enable cellular visualization with high-performance probes, which can present cellular morphology that is highly consistent with that shown by biopsy to provide the possibility of early detection of cancer. Other endoscopic imaging techniques including endoscopic optical coherence tomography (EOCT) and photoacoustic endoscopy (PAE), are also promising for diagnosing gastrointestinal diseases. This review focuses on these technologies and aims to provide an overview of different technologies and their clinical applicability.

Secondary endoscopic submucosal dissection for locally recurrent or incompletely resected gastric neoplasms

AIM

To investigate the feasibility and safety of secondary endoscopic submucosal dissection (ESD) for residual or locally recurrent gastric tumors.

METHODS

Between 2010 and 2017, 1623 consecutive patients underwent ESD for gastric neoplasms at a single tertiary referral center. Among these, 28 patients underwent secondary ESD for a residual or locally recurrent tumor. Our analysis compared clinicopathologic factors between primary ESD and secondary ESD groups.

RESULTS

The en bloc resection and curative rate of resection of secondary ESD were 92.9% and 89.3%, respectively. The average procedure time of secondary ESD was significantly longer than primary ESD (78.2 min vs 55.1 min, P = 0.004), and the adverse events rate was not significantly different but trended slightly higher in the secondary ESD group compared to the primary ESD group (10.7% vs 3.8%, P = 0.095). Patients who received secondary ESD had favorable outcomes without severe adverse events. During a mean follow-up period, no local recurrence occurred in patients who received secondary ESD.

CONCLUSION

Secondary ESD of residual or locally recurrent gastric tumors appears to be a feasible and curative treatment though it requires greater technical efficiency and longer procedure time.

In vivo histological diagnosis for gastric cancer using endocytoscopy

AIM

To examine usefulness of virtual biopsy using endocytoscopy by comparing the in vivo endocytoscopic and histopathological images of gastric cancers.

METHODS

Endocytoscopy was performed in 30 patients with early gastric cancer. Of these, 26 patients showed well differentiated adenocarcinomas, while 4 patients showed poorly differentiated adenocarcinomas (including one signet ring cell carcinoma). Cancerous and non-cancerous areas were observed after double staining with 0.05% crystal violet and 0.1% methylene blue. The endocytoscopic images obtained were evaluated by an expert endoscopist and an expert pathologist without knowledge of patient clinical data, and endocytoscopic and histopathological diagnoses were compared.

RESULTS

The endocytoscopic images of the cancerous area were assessed as evaluable in 25 (83.3%) and 27 (90%) patients by endoscopist A and pathologist B, respectively, and those of the non-cancerous area as evaluable in 28 (93.3%) and 23 (76.7%) patients by the endoscopist and pathologist, respectively. The sensitivity, specificity, and diagnostic accuracy of gastric cancer diagnosis using evaluable endocytoscopic images were 88.0% and 92.9%, and 90.6% by endoscopist A, and 88.9% and 91.3%, and 90.0% by pathologist B, respectively. Evaluation of the diagnostic concordance rate between the endoscopist and the pathologist by inter-observer agreement calculation revealed no significant difference between the two observers. The inter-observer agreement (κ-value) for endocytoscopic diagnosis was 0.745.

CONCLUSION

Endocytoscopy is useful for the differentiation of cancerous from non-cancerous gastric mucosa, making it a promising tool for virtual biopsy.

Magnifying Endoscopy with Blue Laser Imaging Improves the Microstructure Visualization in Early Gastric Cancer: Comparison of Magnifying Endoscopy with Narrow-Band Imaging

Backgrounds

Magnifying endoscopy with blue laser imaging (ME-BLI) for diagnosis of early gastric cancer (EGC) is as effective as magnifying endoscopy with narrow-band imaging (ME-NBI). However, there are different EGCs in microstructure visualization between ME-BLI and ME-NBI. This study aimed to clarify the pathological features of the EGCs, in which microstructure visualization was different between ME-NBI and ME-BLI.

Methods

EGCs were classified into groups A (irregular microsurface pattern (MSP) in ME-BLI and absent MSP in ME-NBI), B (irregular MSP in two modalities), or C (absent MSP in two modalities), according to the vessel plus surface classification. We compared the pathological features of EGCs between the three groups.

Results

17, four, and five lesions could be evaluated in detail in groups A, B and C, respectively. Well-differentiated adenocarcinomas with shallow crypts were more frequent in group A than in group B (58.8 and 0%, resp.). The mean crypt depth of group A was significantly shallower than that of group B (56 ± 20, 265 ± 64 μm, resp., P = 0.0002).

Conclusions

ME-BLI could better visualize the microstructures of the EGCs with shallow crypts compared with ME-NBI. Therefore, ME-BLI could enable a more accurate diagnosis of EGC with shallow crypts.

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.

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.

Magnifying endoscopy simple diagnostic algorithm for early gastric cancer (MESDA-G)

Gastric cancer is the third leading cause of cancer death worldwide. Early detection and accurate diagnosis of mucosal cancer is desirable in order to achieve decreased mortality; cause-specific survival of patients with early gastric cancer is reported to exceed 95%. Endoscopy is the functional modality to detect early cancer; however, the procedure is not definitive when using conventional white-light imaging. In contrast, magnifying narrow-band imaging (M-NBI), a novel endoscopic technology, is a powerful tool for characterizing gastric mucosal lesions because it can visualize the microvascular architecture and microsurface structure. To date, many reports on the diagnosis of early gastric cancer by M-NBI, including multicenter prospective randomized studies conducted in Japan, have been published in peer-reviewed international journals. Based on these published data, we devised a proposal for a diagnostic strategy for gastric mucosal cancer using M-NBI to simplify the process of diagnosis and improve accuracy. Herein, we recommend a diagnostic algorithm for early gastric cancer using magnifying endoscopy.

Guidelines for endoscopic submucosal dissection and endoscopic mucosal resection for early gastric cancer

In response to the rapid and wide acceptance and use of endoscopic treatments for early gastric cancer, the Japan Gastroenterological Endoscopy Society (JGES), in collaboration with the Japanese Gastric Cancer Association (JGCA), has produced 'Guidelines for ESD and EMR for Early Gastric Cancer', as a set of basic guidelines in accordance with the principles of evidence-based medicine. These Guidelines cover the present state of knowledge and are divided into the following seven categories: Indications, Preoperative diagnosis, Techniques, Evaluation of curability, Complications, Long-term postoperative surveillance, and Histology. Twenty-three statements were finally accepted as guidelines, and the majority of these were obtained from descriptive studies with lower evidence levels. A number of statements had to be created by consensus (the lowest evidence level), as evidence levels remain low for many specific areas in this field.

Improving the Endoscopic Detection Rate in Patients with Early Gastric Cancer

Endoscopists should ideally possess both sufficient knowledge of the endoscopic gastrointestinal disease findings and an appropriate attitude. Before performing endoscopy, the endoscopist must identify several risk factors of gastric cancer, including the patient's age, comorbidities, and drug history, a family history of gastric cancer, previous endoscopic findings of atrophic gastritis or intestinal metaplasia, and a history of previous endoscopic treatments. During endoscopic examination, the macroscopic appearance is very important for the diagnosis of early gastric cancer; therefore, the endoscopist should have a consistent and organized endoscope processing technique and the ability to comprehensively investigate the entire stomach, even blind spots.

Value of magnifying endoscopy combined with Fujinon intelligent chromoendoscopy in diagnosis of flat gastric lesionsss

AIM: To explore the value of magnifying endoscopy combined with Fujinon intelligent chromoendoscopy (FICE) in the diagnosis of flat gastric lesions.

METHODS: From September 2013 to August 2014, 248 patients with flat gastric lesions who underwent magnifying endoscopy combined with FICE were included. Pit patterns and capillary morphology were observed and typed to predict pathological outcome, and the results were compared with histological results to evaluate the consistency and relevance.

RESULTS: Gastric atrophy was mainly classified by FICE as types C, D, and E gastric pits patterns; intestinal metaplasia mainly as types D and E pits; high-grade intraepithelial neoplasia and early gastric cancer mainly as types E and F gastric pits. Magnifying endoscopy combined with FICE had good consistency with histology in the diagnosis of atrophy, intestinal metaplasia, high-grade intraepithelial neoplasia and early gastric cancer.

CONCLUSION: Magnifying endoscopy combined with FICE can accurately diagnose gastric atrophy, intestinal metaplasia, intraepithelial neoplasia and early cancer.

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.

Quantitative identification of mucosal gastric cancer under magnifying endoscopy with flexible spectral imaging color enhancement

BACKGROUND AND AIM

Magnifying endoscopy with flexible spectral imaging color enhancement (FICE) is clinically useful in diagnosing gastric cancer and determining treatment options; however, there is a learning curve. Accurate FICE-based diagnosis requires training and experience. In addition, objectivity is necessary. Thus, a software program that can identify gastric cancer quantitatively was developed.

METHODS

A bag-of-features framework with densely sampled scale-invariant feature transform descriptors to magnifying endoscopy images of 46 mucosal gastric cancers was applied. Computer-based findings were compared with histologic findings. The probability of gastric cancer was calculated by means of logistic regression, and sensitivity and specificity of the system were determined.

RESULTS

The average probability was 0.78 ± 0.25 for the images of cancer and 0.31 ± 0.25 for the images of noncancer tissue, with a significant difference between the two groups. An optimal cut-off point of 0.59 was determined on the basis of the receiver operating characteristic curves. The computer-aided diagnosis system yielded a detection accuracy of 85.9% (79/92), sensitivity for a diagnosis of cancer of 84.8% (39/46), and specificity of 87.0% (40/46).

CONCLUSION

Further development of this system will allow for quantitative evaluation of mucosal gastric cancers on magnifying gastrointestinal endoscopy images obtained with FICE.

Clinical implication of endoscopic gross appearance in early gastric cancer: revisited

BACKGROUND

The macroscopic appearance of early gastric cancer (EGC) is known to reflect its growth patterns. The purpose of this study was to investigate the role of the endoscopic appearance as a predictor of clinical behavior in EGC.

METHODS

Between January 2005 and December 2008, 1,845 patients were diagnosed with EGC and underwent surgery. The clinicopathologic characteristics were retrospectively analyzed according to gross appearance. Endoscopic findings were classified by predominant type as elevated, flat, or depressed. Flat and depressed types were categorized together as nonelevated type.

RESULTS

The proportions of elevated, flat, and depressed types were 16.6, 28.6, and 54.8 %. The gross appearance of the elevated type predominantly showed well/moderate differentiation, whereas the flat and depressed types showed signet-ring cells and poor differentiation, respectively. When the elevated and nonelevated types were compared, submucosal invasion, lymphovascular invasion (LVI), and lymph-node metastasis (LNM) were higher in elevated than in nonelevated type. In differentiated EGC, submucosal invasion, LVI, LNM, and multiplicity were significantly higher in the elevated than the nonelevated type. These patterns were significantly common in the order elevated, depressed, and flat types. In undifferentiated EGC, submucosal invasion, LVI, and perineural invasion were significantly higher in elevated than in nonelevated type. These patterns were significantly common in the order elevated, depressed, and flat types. However, LNM was not significantly different based on gross appearance in undifferentiated EGC.

CONCLUSIONS

Clinical behavior differs according to endoscopic appearance in EGC. The endoscopic appearance of EGC may facilitate prediction of clinical behavior, particularly in differentiated EGC.

Screening for precancerous lesions of upper gastrointestinal tract: from the endoscopists' viewpoint

Upper gastrointestinal tract cancers are one of the most important leading causes of cancer death worldwide. Diagnosis at late stages always brings about poor outcome of these malignancies. The early detection of precancerous or early cancerous lesions of gastrointestinal tract is therefore of utmost importance to improve the overall outcome and maintain a good quality of life of patients. The desire of endoscopists to visualize the invisibles under conventional white-light endoscopy has accelerated the advancements in endoscopy technologies. Nowadays, image-enhanced endoscopy which utilizes optical- or dye-based contrasting techniques has been widely applied in endoscopic screening program of gastrointestinal tract malignancies. These contrasting endoscopic technologies not only improve the visualization of early foci missed by conventional endoscopy, but also gain the insight of histopathology and tumor invasiveness, that is so-called optical biopsy. Here, we will review the application of advanced endoscopy technique in screening program of upper gastrointestinal tract cancers.

Magnifying chromoendoscopy combined with immunohistochemical staining for early diagnosis of gastric cancer

AIM: To assess the diagnostic value of using magnifying chromoendoscopy combined with immunohistochemical staining of proliferating cell nuclear antigen (PCNA) and p53 in the detection of gastric precancerous lesions.

METHODS: Ninety-five patients who were treated for abdominal discomfort, abdominal pain, bloating, and acid reflux at our hospital from January 2010 to December 2011 were included in the study. An ordinary gastroscopic procedure was initially performed to select the lesions. All subjects underwent magnifying chromoendoscopy to observe morphological changes of gastric pits. Biopsies were then taken from each area of interest and sent for pathological examination and detection of PCNA and p53 expression by immunohistochemistry. An immunoreactivity score for each lesion was calculated. Based on immunoreactivity scores, immunohistochemical staining was then considered.

RESULTS: Compared to intestinal metaplasia, gastric pits were more diverse in size, more irregular in shape, and more disorderly in arrangement in moderate and severe dysplasia. PCNA and p53 expression was significantly higher in precancerous lesions (intestinal metaplasia and dysplasia) than in chronic gastritis. PCNA expression showed an upward trend in types A-F pits. The number of cases that showed strong PCNA positivity increased significantly with an increase in the severity of lesions. Rank sum test for independent samples showed that p53 expression was significantly higher in types E and F pits than in types A-D pits (H = 33.068, P = 0.000). Rank sum test for independent samples showed that PCNA expression was significantly higher in types E and F pits than in types A-D pits (H = 31.791, P = 0.001).

CONCLUSION: The presence of types E and F pits, in which p53 and PCNA are highly expressed, is highly suggestive of the occurrence of early cancer, and patients developing these changes should be closely followed.

The Usefulness of Magnifying Endoscopy and Narrow-Band Imaging in Measuring the Depth of Invasion before Endoscopic Submucosal Dissection

With the widespread application of endoscopic submucosal dissection for the treatment of gastrointestinal neoplasms, accurate determination of the invasion depth prior to intervention has become an indispensable part of treatment planning. Narrow-band imaging (NBI) is a novel endoscopic technique that may enhance the accuracy of diagnosis. Magnifying endoscopy with NBI has been shown to be effective for determining invasion depth for intrapapillary capillary loop classification of esophageal cancer and microvascular pattern of stomach cancer. Such precise pre-treatment staging of early neoplastic lesions in the gastrointestinal tract warrants timely initiation of disease-tailored treatment and, ultimately, better quality of life and improved patient survival.

Prediction of invasion depth for submucosal differentiated gastric cancer by magnifying endoscopy with narrow-band imaging

The usefulness of determining gastric cancer invasion depth by magnifying endoscopy with narrow-band imaging (NBI-ME) has not been established. The objective of our study was to retrospectively compare NBI-ME images of differentiated submucosal (SM) 1 cancer with those of SM2 to identify the indicators of invasion depth for SM2 gastric cancer. Fifteen patients with SM1 differentiated gastric cancer and 20 with SM2 removed by endoscopic submucosal resection (ESD) were included. NBI-ME images matching the invasion depth of pathological specimens were examined to define the following three findings as diagnostic indicators of SM2: non-structure, scattery vessels and multi-caliber vessels. The relationship between indicators and invasion depth and between indicator score and invasion depth was examined in 27 patients (SM1/SM2: 11/16) with depressed-type gastric cancer (D-GC) and in 8 (SM1/SM2: 4/4) with protruding-type gastric cancer (P-GC). Diagnostic accuracy for invasion depth determined by four endoscopists using regular endoscopic images was compared with that determined by the same endoscopists using NBI-ME. In D-GC, all three indicators were significantly more frequent in SM2 than in SM1 (p<0.05). All D-GC with ≥2 points were SM2, demonstrating a significant difference in score distribution between SM1 and SM2 (p<0.05). In D-GC, diagnostic accuracy by NBI-ME was higher than that by regular endoscopy by all 4 endoscopists (p<0.05). NBI-ME findings of non-structure, scattery vessels and multi-caliber vessels can possibly serve as indicators of SM2 invasion in differentiated D-GC. Scoring of the three indicators was significant.

A case of gastric mucosa-associated lymphoid tissue lymphoma in which magnified endoscopy with narrow band imaging was useful in the diagnosis

Recently, we reported a case of gastric mucosa-associated lymphoid tissue (MALT) lymphoma presenting with unique vascular features. In the report, we defined the tree-like appearance (TLA) on the images of abnormal blood vessels which resembled branches from the trunk of a tree in the shiny mucosa, in which the glandular structure was lost. The 67-year-old female was diagnosed with gastric MALT lymphoma. The patient received eradication therapy for H. pylori. Conventional endoscopy revealed multiple ill-delineated brownish depressions in the stomach and cobblestone-like mucosa was observed at the greater curvature to the posterior wall of the upper gastric body 7 mo after successful eradication. Unsuccessful treatment of gastric MALT lymphoma was suspected on conventional endoscopy. Conventional endoscopic observations found focal depressions and cobblestone-like appearance, and these lesions were subsequently observed using magnified endoscopy combined with narrow band imaging to identify abnormal vessels presenting with a TLA within the lesions. Ten biopsies were taken from the area where abnormal vessels were present within these lesions. Ten biopsies were also taken from the lesions without abnormal vessels as a control. A total of 20 biopsy samples were evaluated to determine whether the diagnosis of MALT lymphoma could be obtained histologically from each sample. A positive diagnosis was obtained in 8/10 TLA (+) sites and in 2/10 TLA(-) sites. Target biopsies of the site with abnormal blood vessels can potentially improve diagnostic accuracy of gastric MALT lymphoma.

Application of magnifying narrow-band imaging endoscopy for diagnosis of early gastric cancer and precancerous lesion

Background

Gastric carcinoma is the second commonest cause of cancer deaths worldwide. Early detection and diagnosis of gastric cancer in the stomach is important for improving the prognosis of gastric cancer. This retrospective study was designed to investigate the value of magnifying narrow-band imaging (NBI) in the diagnosis of precancerous lesions and early gastric cancer.

Methods

This study included 122 patients who were diagnosed with early gastric cancer or precancerous gastric lesions by endoscopy. The patients underwent an examination with conventional endoscopy, magnifying NBI, and magnifying chromoendoscopy. Images resolution was evaluated, and the morphology, pit patterns and blood capillary forms of lesions were analyzed. The presence of gastric carcinoma and high grade intraepithelial neoplasia in the biopsy samples was considered as a positive pathological result, which is used to assess accuracy of endoscopic diagnosis.

Results

For image resolution, magnifying NBI and magnifying chromoendoscopy were significantly superior to magnifying conventional endoscopy in morphology, pit pattern and blood capillary form (P < 0.01), and magnifying NBI was significantly superior to magnifying chromoendoscopy in blood capillary form (P < 0.01). IV, V₁, and VI type of gastric pit pattern were detected in 14 cases, 43 cases, and 17 cases in patients with high grade intraepithelial neoplasia, respectively. V₁ and VI type of gastric pit pattern were detected in 9 cases and 39 cases in patients with early gastric cancer, respectively. The presence of irregular minute vessels and variation in the caliber of vessels was found in 109 cases. The accuracy, sensitivity, specificity, false positive rate and false negative rate for diagnosis of early gastric cancer and precancerous gastric lesions were 68.9%, 95.1%, 63.1%, 24.5%, and 32.4% for conventional endoscopy, 93.6%, 92.7%, 94.5%, 5.7%, and 6.9% for magnifying NBI, and 91.3%, 88.6%, 93.2%, 13.2%, and 21.48% for magnifying chromoendoscopy, respectively.

Conclusions

This study demonstrates that magnifying NBI is superior to conventional endoscopy in the diagnosis of early gastric cancer and precancerous gastric lesions, and can be used for screening early malignancies of the stomach.

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.

Magnifying chromoendoscopic findings of early gastric cancer and gastric adenoma

PURPOSE

In the field of colorectal cancer and adenoma, Kudo's classification of pit pattern with magnifying chromocolonoscopy using crystal violet (CV) staining is now accepted. Magnifying endoscopy using narrow band imaging has been used for the diagnosis of gastric carcinoma; the characteristic findings of microvascular patterns have been demonstrated. However, there was limited information on magnified endoscopic findings with CV staining for gastric neoplasms in terms of their pit patterns.

METHODS

Magnifying chromoendoscopy with CV was performed in 175 patients with early gastric cancer and 18 with gastric adenoma, prior to treatment. Surface patterns of gastric tumors were classified into five types: (1) long tubular pit pattern, (2) irregular size pit pattern, (3) small round pit pattern, (4) destroyed pit pattern, and (5) non-structural pattern.

RESULTS

Long tubular pit pattern was most common in gastric adenoma. Well differentiated adenocarcinoma and papillary adenocarcinoma tended to show different size of pit pattern or destroyed pit pattern. Small round pit pattern was most commonly seen in moderately differentiated adenocarcinoma. Non-structural pattern was most frequently observed in poorly differentiated adenocarcinoma and signet ring cell carcinoma (P < 0.0001).

CONCLUSION

For gastric neoplasms, magnifying endoscopy may help predict histopathological type.

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.

Serum peptidome profiling in patients with gastric cancer

To identify discriminating protein patterns in serum samples between gastric cancer patients (early and advanced stages) and healthy controls. We used magnetic bead-based separation followed by matrix-assisted laser desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) to identify patients with gastric cancer. In total, serum samples from 62 gastric cancer patients (32 in the training set and 30 in the test set; 19 of which had early-stage tumors and 43 of which had advanced-stage tumors) and 64 healthy controls (32 in the training set and 32 in the test set) were analyzed. The mass spectra, analyzed using ClinProTools software, distinguished between cancer patients and healthy individuals based on three different algorithm models. In the training set, patients with gastric cancer could be identified with a mean sensitivity of 94.7% and a mean specificity of 99%. Similar results were obtained with the test set, showing 79.3% sensitivity and 86.5% specificity. Our study demonstrates the high sensitivity and specificity of screening serum protein patterns using MALDI-TOF MS for the identification of patients with gastric cancer.

Morphometry for microvessels in early gastric cancer by narrow band imaging-equipped magnifying endoscopy

BACKGROUND AND AIM

Microvascular architecture is a variable characterizing early gastric cancer (EGC) against the background. The aims of the present study were to measure morphological variables of the microvessels and to compare the variables between EGC and the background.

METHODS

Narrow band imaging (NBI)-equipped magnifying endoscopic pictures from 32 patients with EGC were used. The endoscopic pictures were taken under maximal magnification and processed for the microvessels in an in-focus area after correction of image distortion. The segmented microvessels were numbered for microvessel density (counts/mm(2)) and vascular bed area (% ratio of vascular bed against the region of interest). The microvessels were further processed for a set of skeletonized pixels to count the characteristic points, including end-points, crossing points, branching points and connecting points.

RESULTS

Microvessels in cancer were found to have a significantly larger connected point number (20.5 ± 6.1, P = 0.0002) than those in the background (17.4 ± 3.9). Numbers of the end-points and branching points were found to be significantly larger in cancer than in the background (end-points 3.6 ± 0.7 for cancer vs 3.3 ± 0.4 for background, P = 0.0005; branching points 0.8 ± 0.4 for cancer vs 0.7 ± 0.2 for background, P = 0.0014). However, microvessel density, vascular bed area and mean diameter did not significantly differ between cancer and the background.

CONCLUSION

This finding can be considered to reflect the reported observation of an irregular vascular pattern in gastric cancer. This method may provide a means for microvessel morphometry, regardless of the organ studied.

An esophageal SCC case which could be distinguished from non-neoplasia using magnifying endoscopy with NBI imaging

In this case, narrow-band imaging helped to distinguish esophagitis. The case involved an 81-year-old female was being seen as an outpatient because of Gastroesophageal Reflux Disease (GERD) symptoms associated with an esophageal hiatal hernia. Endoscopy showed long reddish lesions on the posterior wall of the lower thoracic esophagus. Non-magnifying endoscopic images with white light initially suggested reflux esophagitis. Magnifying endoscopy with narrow-band imaging showed proliferation of intraepithelial papillary capillary loop-like vessels as well as irregular widening and narrowing of vessels, so the patient's condition was diagnosed as superficial esophageal cancer. Endoscopic submucosal dissection was carried out.

Magnifying endoscopic findings of the surface structure of non-cancerous mucosa surrounding differentiated and undifferentiated gastric carcinoma

BACKGROUND

Several reports have described the usefulness of magnifying endoscopy in observing the surface structure in gastric neoplasia. The aim of the present study was to evaluate the characteristics of the surface structure of non-cancerous mucosa surrounding gastric cancer.

METHODS

Sixty Japanese patients with early gastric cancer were enrolled in this study. We observed the non-cancerous gastric mucosa surrounding gastric carcinoma by magnifying endoscopy and classified the magnified view into four patterns: (A) dotted; (B) short-linear; (C) striped; and (D) granular, according to Sakaki's classification.

RESULTS

All patients were diagnosed as having Helicobacter pylori infection, and histological evaluation revealed 46 types of differentiated and 14 types of undifferentiated-type gastric carcinomas. There were significant differences in the gender, age and endoscopic-atrophic-border scale between patients with these two types. In all, the surface structure at 240 points (4 points each in 60 patients) of non-cancerous mucosa was observed by magnifying endoscopy. The prevalences of the surface patterns of the mucosa surrounding differentiated carcinoma were: A, 1.1%; B, 8.1%; C, 28.3%; D, 62.5%, and those of the mucosa surrounding undifferentiated carcinoma were: A, 8.9%; B, 73.2%; C, 14.3%; D, 3.6%. There were significant differences in the surface structure of the non-cancerous mucosa surrounding differentiated and undifferentiated gastric carcinoma.

CONCLUSION

The microsurface structure of the gastric mucosa surrounding gastric cancer lesions differed between patients with differentiated and undifferentiated gastric cancer. These findings are expected to be useful for the early detection of gastric carcinoma lesions or for the determination of extensions of carcinoma lesions.

Narrow band imaging for the detection of gastric intestinal metaplasia and dysplasia during surveillance endoscopy

Background Surveillance of premalignant gastric lesions relies mainly on random biopsy sampling. Narrow band imaging (NBI) may enhance the accuracy of endoscopic surveillance of intestinal metaplasia (IM) and dysplasia.We aimed to compare the yield of NBI to white light endoscopy (WLE) in the surveillance of patients with (IMa)and dysplasia.Methods Patients with previously identified gastric IM or dysplasia underwent a surveillance endoscopy. Both WLE and NBI were performed in all patients during a single procedure. The sensitivity of WLE and NBI for the detection of premalignant lesions was calculated by correlating endoscopic findings to histological diagnosis.Results Forty-three patients (28 males and 15 females,mean age 59 years) were included. IM was diagnosed in 27 patients; 20 were detected by NBI and WLE, four solely by NBI and three by random biopsies only. Dysplasia was detected in seven patients by WLE and NBI and in two patients by random biopsies only. Sixty-eight endoscopically detected lesions contained IM: 47 were detected by WLE and NBI, 21 by NBI only. Nine endoscopically detected lesions demonstrated dysplasia: eight were detected by WLE and NBI, one was detected by NBI only.The sensitivity, specificity, positive and negative predictive values for detection of premalignant lesions were 71, 58,65 and 65% for NBI and 51, 67, 62 and 55% for WLE,respectively.Conclusions NBI increases the diagnostic yield for detection of advanced premalignant gastric lesions compared to routine WLE.

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.

Endoscopists' view on superficial spreading type of early gastric cancer--endoscopic resection or surgery?

OBJECTIVE

The superficial spreading type of early gastric cancer (EGC) possesses unique features different from other types of EGC. We aimed to elucidate the clinicopathological features of superficial spreading type of EGC.

MATERIAL AND METHODS

We analyzed 1455 EGC lesions from 1398 patients who had undergone surgical treatment at Samsung Medical Center from 2000 to 2002. Then the clinicopathological features of 224 superficial-spreading EGC lesions (15.4%) was compared to that of 1231 lesions of a common type of EGC.

RESULTS

In the superficial spreading type of EGC, the incidence of undifferentiated type and submucosal invasion were higher than those of common type of EGC (55.4 vs 38.0%, p < .01 and 58.5 vs 37.8%, p < .01, respectively). Lymph node metastasis and lymphovascular invasion were more frequent in superficial spreading type than in common type of EGC (19.2 vs 7.6%, p < .01 and 15.2 vs 7.4%, p < .01, respectively). There was no difference in recurrence rate or 5-year survival rate between the two groups.

CONCLUSION

Considering higher risk of submucosal invasion and lymph node metastasis in superficial spreading type, a careful consideration should be done before the application of endoscopic resection to the superficial spreading type of EGC.

Magnification chromoendoscopy for the diagnosis of gastric precancerous lesions and early gastric cancer: an analysis of 196 cases

AIM: To evaluate the feasibility and accuracy of magnification chromoendoscopy in the diagnosis of gastric atrophy, intestinal metaplasia (IM), atypical hyperplasia and early gastric cancer.

METHODS: One hundred and ninety-six patients were examined by magnification chromoendoscopy to observe the changes in gastric pits and microvessels. The classification criteria were then developed for the diagnosis of precancerous lesions and early gastric cancer. Histopathological examination of gastric mucosal specimens from these patients was also performed.

RESULTS: Of the 196 patients, 46 were diagnosed with superficial gastritis, 76 with gastric atrophy, 37 with atrophy and IM, 36 with atrophy and dysplasia, and 1 with early gastric cancer. The diagnostic coincidence rates between magnification chromoendoscopy and pathological examination for gastric atrophy, atrophy with IM, and atrophy with dysplasia were 84.2%, 81.1% and 72.2%, respectively. The total detection rate of precancerous lesions by magnification chromoendoscopy was 80.5%.

CONCLUSION: Magnification chromoendoscopy has a high diagnostic value for gastric precancerous lesions and early gastric cancer.

Effectiveness of narrow-band imaging magnification for invasion depth in early colorectal cancer

AIM

To evaluate the surface microvascular patterns of early colorectal cancer (ECC) using narrow-band imaging (NBI) with magnification and its effectiveness for invasion depth diagnosis.

METHODS

We studied 112 ECC lesions [mucosal/submucosal superficial (m/sm-s), 69; sm-deep (sm-d), 43] > or = 10 mm that subsequently underwent endoscopic or surgical treatment at our hospital. We compared microvascular architecture revealed by NBI with magnification to histological findings and then to magnification colonoscopy pit pattern diagnosis.

RESULTS

Univariate analysis indicated vessel density: non-dense (P < 0.0001); vessel regularity: negative (P < 0.0001); caliber regularity: negative (P < 0.0001); vessel length: short (P < 0.0001); and vessel meandering: positive (P = 0.002) occurred significantly more often with sm-d invasion than m/sm-s invasion. Multivariate analysis showed sm-d invasion was independently associated with vessel density: non-dense [odds ratio (OR) = 402.5, 95% confidence interval (CI): 12.4-13 133.1] and vessel regularity: negative (OR = 15.9, 95% CI: 1.2-219.1). Both of these findings when combined were an indicator of sm-d invasion with sensitivity, specificity and accuracy of 81.4%, 100% and 92.9%, respectively. Pit pattern diagnosis sensitivity, specificity and accuracy, meanwhile, were 86.0%, 98.6% and 93.8%, respectively, thus, the NBI with magnification findings of non-dense vessel density and negative vessel regularity when combined together were comparable to pit pattern diagnosis.

CONCLUSION

Non-dense vessel density and/or negative vessel regularity observed by NBI with magnification could be indicators of ECC sm-d invasion.

Confocal endomicroscopy for phenotypic diagnosis of gastric cancer

BACKGROUND AND AIM

Relationships between mucin phenotype and malignant potential in gastric cancers have attracted attention. We attempted to assess the possibility of obtaining phenotypic diagnoses by confocal endomicroscopy.

METHODS

Confocal images of target lesions were obtained in 29 of 40 patients with gastric cancer. Appearances of the brush border, goblet cells, and gastric foveolar epithelium were investigated with immunohistochemical staining using CD10, MUC2, and human gastric mucin to evaluate phenotypic expression in gastric carcinomas. Confocal images were compared with immunohistochemical findings for goblet cells and brush borders.

RESULTS

Both the endoscopists and the pathologist obtained high accuracy rates for differential diagnosis. Sensitivity and specificity for goblet cells were 85.7% and 92.3% (Endoscopist A), and 85.7% and 88.5% (Endoscopist B). The kappa-value for correspondence between two endoscopists for the diagnosis of goblet cells in confocal images was 0.73. Sensitivity and specificity for the brush border were 93.8% and 91.7% (Endoscopist A), and 81.3% and 91.7% (Endoscopist B). The kappa-value for correspondence between two endoscopists for diagnosis of the brush border in confocal images was 0.79. Intestinal phenotypic gastric cancers show a brush border, goblet cells, or both. Sensitivity and specificity for the intestinal phenotype in confocal endomicroscopy were 90.9% and 77.8% (Endoscopist A), and 86.4% and 83.3% (Endoscopist B).

CONCLUSION

The confocal endomicroscopic diagnosis of the mucin phenotype in gastric cancers was limited to intestinal and mixed phenotypes, but may be useful for the diagnosis of mucin phenotype and differential diagnosis.

Structural enhancement and video endoscopy: results of a large prospective comparative study

INTRODUCTION

The structural-enhancement (SE) function electronically improves the video-endoscopic signal of Olympus processors (EXERA CV-160 or greater), enabling an increase in relief that may help in the detection of flat or ulcerated and raised lesions, especially those of small size. We assessed the diagnostic impact of this technique in the screening of lesions during basic video colonoscopy.

METHODS

Maximum-level SE was programmed into processors on alternate weeks, and endoscopy dates were planned by an assistant unaware of the SE schedule, thus ensuring randomization. The endoscopists-senior practitioners with 3-29 years of digestive endoscopy practice-were informed of the experiment >3 weeks before it began and were not told about it again either before or during the study. This was to ensure that endoscopy examinations were performed without over-awareness of the technical conditions. GIF-100 to -160 Olympus endoscopes were used.

RESULTS

During the study, 606 patients underwent upper digestive video-endoscopy, 305 with and 301 without the use of the SE function. Of 645 patients who underwent video colonoscopy, 593 were included in the study and 52 were excluded due to poor cleansing (8%); of those included, 330 were analyzed with and 263 without the SE function. We observed no differences in the detection of lesions (small or large) by either upper digestive endoscopy or video colonoscopy.

CONCLUSION

This is the first study comparing video-endoscopy diagnosis with or without SE during upper digestive endoscopy and colonoscopy. The SE function available on Olympus video-endoscopy processors had no impact on the detection of lesions, not even on those of very small size.

Ease of early gastric cancer demarcation recognition: a comparison of four magnifying endoscopy methods

BACKGROUND AND AIM

Various techniques using magnifying endoscopy (ME) have been developed to enhance images of early gastric cancer (EGC) demarcations, which are often obscure. We investigated four ME methods to determine which is most effective in enhancing the recognition of EGC demarcations: conventional ME (CME), ME with narrow band imaging (NBI-ME), enhanced-magnification endoscopy with acetic acid (EME), and ME with NBI and acetic acid (NBI-EME).

METHODS

Thirty-seven successive patients having a total of 40 EGCs participated in the investigation. The endoscope was fixed and magnification images of EGC demarcations in each patient were recorded using four different ME methods (CME, NBI-ME, EME and NBI-EME). Eight experts and eight non-experts scored each of the four images of each lesion for ease of recognition of demarcation (1 to 4, with 4 being easiest).

RESULTS

The mean scores of expert and non-expert judges, respectively, for images acquired using each technique were: CME 1.23, 1.24; NBI-ME 2.61, 2.95; EME 2.62, 2.32 and NBI-EME 3.54, 3.50. There were significant differences between the mean scores for the four techniques (P < 0.0001) using one-way repeated-measures anova. In a Bonferroni's multiple comparison, the average scores (expert and non-expert) of images acquired using NBI-EME were significantly higher than those acquired using other methods; images acquired by NBI-ME or EME also scored significantly higher than those by CME. Non-experts also scored NBI-ME images significantly higher than CME and EME images.

CONCLUSIONS

Early gastric cancer demarcations were recognized most easily using NBI-EME, and more easily using EME or NBI-ME than CME.

Evaluation and validation of computed virtual chromoendoscopy in early gastric cancer

BACKGROUND

The Flexible spectral Imaging Color Enhancement (FICE) system estimates the spectrum reflectance from a white-light endoscopic image and reconstitutes a color image from the wavelength, including useful information about the GI tract. The aim of this study was to investigate the usefulness of FICE with a specific wavelength in the assessment of early gastric cancers (EGCs), and the relationship between the FICE visualization and blood vessels.

DESIGN

A retrospective study.

SETTING

Department of Endoscopy, Hiroshima University, Hiroshima, Japan.

PATIENTS AND MAIN OUTCOME MEASUREMENTS

The study subjects consisted of 100 patients with EGCs (78 differentiated, 22 undifferentiated) who underwent an endoscopic or surgical resection. We analyzed the wavelengths to generate the maximum difference of the spectral reflectance between the normal gastric mucosa and the EGCs. We observed the same visual field first with white-light endoscopy and then with the FICE system. Then, we scored the demarcation of color between the cancer and the normal mucosa of white-light endoscopic observation and FICE observation, each without magnification. We examined the relationship between the score of the FICE image and the section of the vascular space.

RESULTS

The wavelength that generated the maximum difference in the tissue was 530 nm. The score of the FICE observation improved in 46 cases (46%), was unchanged in 54 cases (54%), and decreased in no cases (0%). There was a correlation between the score of the FICE images and the section of the vascular spaces.

CONCLUSIONS

The FICE observation demonstrated that setting the wavelength at 530 nm resulted in an improvement in the visualization of the EGCs. It is thought that the FICE system is noninvasive and may more easily detect EGC without dye during both routine and detailed examinations.

Usefulness of magnifying endoscopy in post-endoscopic resection scar for early gastric neoplasm: A prospective short-term follow-up endoscopy study

AIM: To investigate the relationship between post-endoscopic resection (ER) scars on magnifying endoscopy (ME) and the pathological diagnosis in order to validate the clinical significance of ME.

METHODS: From January, 2007 to June, 2008, 124 patients with 129 post-ER scar lesions were enrolled. Mucosal pit patterns on ME were compared with conventional endoscopy (CE) findings and histological results obtained from targeted biopsies.

RESULTS: CE findings showed nodular scars (53/129), erythematous scars (85/129), and ulcerative scars (4/129). The post-ER scars were classified into four pit patterns of sulci and ridges on ME: (I) 47 round; (II) 54 short rod or tubular; (III) 19 branched or gyrus-like; and (IV) 9 destroyed pits. Sensitivity and specificity were 88.9% and 62.5%, respectively, by the presence of nodularity on CE. Erythematous lesions were high sensitivity (100%), but specificity was as low as 36.7%. The range of the positive predictive value (PPV) on CE was as low as 10.6%-25%. Nine type IV pit patterns were diagnosed as tumor lesions, and 120 cases of type I-III pit patterns revealed non-neoplastic lesions. Thus, the sensitivity, specificity, and the PPV of ME were 100%.

CONCLUSION: ME findings can detect the presence of tumor in post-ER scar lesions, and make evident the biopsy target site in short-term follow-up. Further large-scale and long-term studies are needed to determine whether ME can replace endoscopic biopsy.

Argon plasma coagulation under magnifying chromoendoscopy for gastric premalignant lesions: an analysis of 90 cases

AIM: To investigate the effects and clinical value of argon plasma coagulation (APC) on gastric premalignant lesions under magnifying chromoendoscopy (MCE).

METHODS: A total of 90 cases with gastric premalignant lesions underwent argon plasma coagulation under magnifying chromoendoscopy using Fujinon EG-590ZW magnifying endoscope in combination with methylene blue staining. The changes of microstructures after treatment were studied and compared with histopathology.

RESULTS: Six months after argon plasma coagulation treatment, microstructures of gastric mucosa in 90 cases with intestinal metaplasia and dysplasia were regenerated from type E, F to type C or D (86.7%, 6.7%), and the abnormal hyperplasia blood capillary disappeared. Histopathological tissues changed into active inflammation (85.6%) or atrophic inflammation (8.9%). The ablation rates of microstructures (type E and F) and histopathology (intestinal metaplasia and dysplasia) were 93.0% and 94.4%, respectively.

CONCLUSION: Argon plasma coagulation is a safe and effective method in the treatment of gastric premalignant lesions.

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

BACKGROUND

Conventional endoscopy and chromoendoscopy with indigo carmine dye are usually performed for recognizing adequate tumor-negative lateral margins for successful endoscopic resection of gastric neoplasia. However, chromoendoscopy with indigo carmine dye added to acetic acid has not been used for this purpose.

OBJECTIVE

Our purpose was to compare the diagnostic performance of chromoendoscopy with indigo carmine dye added to acetic acid with that of conventional endoscopy and chromoendoscopy with indigo carmine dye or acetic acid alone.

DESIGN

Prospective study.

SETTING

Social Insurance Funabashi Central Hospital.

PATIENTS

Forty-seven consecutive patients (53 lesions) with early gastric cancer and gastric adenomas who underwent endoscopic submucosal dissection (ESD) from April 2006 to July 2007 were studied.

INTERVENTIONS

All the lesions were examined by the endoscopic modalities before ESD, and the resected specimens were analyzed histopathologically.

MAIN OUTCOME MEASUREMENTS

Two endoscopists independently evaluated the diagnostic performance of each image in terms of recognition of tumor borders with reference to macroscopic and histopathologic findings of resected specimens. We also conducted a substudy to assess interobserver variability.

RESULTS

There was good interobserver agreement between the 2 endoscopists in this study (kappa index = 0.764). The diagnostic performance of chromoendoscopy with indigo carmine dye added to acetic acid was significantly greater than that of any of the other modalities (vs each: P < .005).

CONCLUSIONS

The diagnostic performance of chromoendoscopy with indigo carmine dye added to acetic acid was better compared with conventional endoscopy and chromoendoscopy by using only indigo carmine dye or acetic acid. The applicability of this method for gastric neoplasia merits further investigation.