Magnifying narrow-band imaging endoscopy is superior in diagnosis of early gastric cancer

Endoscopic detection and diagnostic strategies for minute gastric cancer: A real-world observational study

BACKGROUND

Minute gastric cancers (MGCs) have a favorable prognosis, but they are too small to be detected by endoscopy, with a maximum diameter ≤ 5 mm.

AIM

To explore endoscopic detection and diagnostic strategies for MGCs.

METHODS

This was a real-world observational study. The endoscopic and clinicopathological parameters of 191 MGCs between January 2015 and December 2022 were retrospectively analyzed. Endoscopic discoverable opportunity and typical neoplastic features were emphatically reviewed.

RESULTS

All MGCs in our study were of a single pathological type, 97.38% (186/191) of which were differentiated-type tumors. White light endoscopy (WLE) detected 84.29% (161/191) of MGCs, and the most common morphology of MGCs found by WLE was protruding. Narrow-band imaging (NBI) secondary observation detected 14.14% (27/191) of MGCs, and the most common morphology of MGCs found by NBI was flat. Another three MGCs were detected by indigo carmine third observation. If a well-demarcated border lesion exhibited a typical neoplastic color, such as yellowish-red or whitish under WLE and brownish under NBI, MGCs should be diagnosed. The proportion with high diagnostic confidence by magnifying endoscopy with NBI (ME-NBI) was significantly higher than the proportion with low diagnostic confidence and the only visible groups (94.19% > 56.92% > 32.50%, P < 0.001).

CONCLUSION

WLE combined with NBI and indigo carmine are helpful for detection of MGCs. A clear demarcation line combined with a typical neoplastic color using nonmagnifying observation is sufficient for diagnosis of MGCs. ME-NBI improves the endoscopic diagnostic confidence of MGCs.

Unveiling clinicopathologic features and outcomes for endoscopic submucosal dissection of early gastric cancer at gastric angulus in China

BACKGROUND

With advances in endoscopic submucosal dissection (ESD) technique, an increasing number of the Chinese population are being diagnosed with early gastric cancers (EGCs) at gastric angulus. However, the relationship between gastric angulus and EGCs remains obscure.

OBJECTIVES

We aimed to unveil the unreported location characteristics of gastric angulus in Chinese EGC patients and the correlation between the degree of submucosal fibrosis and ESD outcomes.

METHODS

We retrospectively reviewed the medical records of EGC patients treated with ESD from January 2010 to March 2023. We retrospectively investigated and analyzed 740 EGC patients using multiple analyses.

RESULTS

Following gastric antrum (53.1%), the gastric angulus (21.8%) emerged as the second-most prevalent site for EGCs. It had highest incidence of severe submucosal fibrosis and ulceration than the other parts. Multivariate analysis showed independent associations of submucosal fibrosis at the angulus with ulceration (OR: 3.714, 95% CI: 1.041-13.249), procedure duration (OR: 1.037, 95% CI: 1.014-1.061), and perforation complication (OR: 14.611, 95% CI: 1.626-131.277) (all P < 0.05).

CONCLUSIONS

The gastric angulus demonstrates the highest incidence of severe submucosal fibrosis and ulceration for EGCs identified by ESD. This condition is linked to unfavorable outcomes, typically increased perforation risks and prolonged operation duration. Therefore, meticulous dissection is crucial for patients with EGCs in the gastric angulus.

Mucin phenotype and microvessels in early gastic cancer: Magnifying endoscopy with narrow band imaging

Backgrounds

In order to detect early gastric cancer (EGC), this research sought to assess the diagnostic utility of magnifying endoscopy (ME) as well as the significance of mucin phenotype and microvessel features.

Methods

402 individuals with an EGC diagnosis underwent endoscopic submucosal dissection (ESD) at the Department of ME between 2012 and 2020. After adjusting for image distortion, high-magnification endoscopic pictures were taken and examined to find microvessels in the area of interest. The microvessel density was measured as counts per square millimeter (counts/mm2) after segmentation, and the vascular bed's size was computed as a percentage of the area of interest. To identify certain properties of the microvessels, such as end-points, crossing points, branching sites, and connection points, further processing was done using skeletonized pixels.

Results

According to the research, undifferentiated tumors often lacked the MS pattern and showed an oval and tubular microsurface (MS) pattern, but differentiated EGC tumors usually lacked the MS pattern and presented a corkscrew MV pattern. Submucosal invasion was shown to be more strongly associated with the destructive MS pattern in differentiated tumors as opposed to undifferentiated tumors. While lesions with a corkscrew MV pattern and an antrum or body MS pattern revealed greater MUC5AC expression, lesions with a loop MV pattern indicated higher MUC2 expression. Furthermore, CD10 expression was higher in lesions with a papillary pattern and an antrum or body MS pattern.

Conclusion

These results imply that evaluating mucin phenotype and microvessel features in conjunction with magnifying endoscopy (ME) may be a useful diagnostic strategy for early gastric cancer (EGC) detection. Nevertheless, further investigation is required to confirm these findings and identify the best course of action for EGC diagnosis.

Immunotherapy for advanced gastric cancer

Gastric cancer (GC) is believed to be the fifth most common cancer and the third most common cause of death worldwide. Treatment techniques include radiation, chemotherapy, gastrectomy, and targeted treatments are often employed. Some hopeful results from the development of GC immunotherapy have already changed treatment approaches. Along with previous combination medicines, new immunotherapies have been developed that target distinct molecules. Despite ongoing studies into the current therapeutic options and significant improvements in this field, the prognosis for the ailment is poor. Since there are few treatment options and a delay in detection, the illness actually advances, spreads, and metastasizes. The bulk of immunotherapies in use today rely on cytotoxic immune cells, monoclonal antibodies, and gene-transferred vaccines. Immune checkpoint inhibitors have become more popular. In this review, we sought to examine the viewpoint and development of several immunotherapy treatment modalities for advanced GC, as well as the clinical results thus far reported. Additionally, we outlined tumor immune escape and tumor immunosurveillance.

Construction of a nomogram for preoperative prediction of the risk of lymph node metastasis in early gastric cancer

Background

The status of lymph node metastasis (LNM) in patients with early gastric cancer (EGC) is particularly important for the formulation of clinical treatment. The purpose of this study was to construct a nomogram to predict the risk of LNM in EGC before operation.

Methods

Univariate analysis and logistic regression analysis were used to determine the independent risk factors for LNM. The independent risk factors were included in the nomogram, and the prediction accuracy, discriminant ability and clinical practicability of the nomogram were evaluated by the receiver operating characteristic curve (ROC), calibration curve and clinical decision curve (DCA), and 100 times ten-fold cross-validation was used for internal validation.

Results

33 (11.3%) cases of AGC were pathologically confirmed as LNM. In multivariate analysis, T stage, presence of enlarged lymph nodes on CT examination, carbohydrate antigen 199 (CA199), undifferentiated histological type and systemic inflammatory response index (SIRI) were risk factors for LNM. The area under the ROC curve of the nomogram was 0.86, the average area under the ROC curve of the 100-fold ten-fold cross-validation was 0.85, and the P value of the Hosmer-Lemeshow test was 0.60. In addition, the clinical decision curve, net reclassification index (NRI) and Integrated Discriminant Improvement Index (IDI) showed that the nomogram had good clinical utility.

Conclusions

We found that SIRI is a novel biomarker for preoperative prediction of LNM in EGC, and constructed a nomogram for preoperative prediction of the risk of LNM in EGC, which is helpful for the formulation of the clinical treatment strategies.

Effect of anesthesia assistance on the detection rate of precancerous lesions and early esophageal squamous cell cancer in esophagogastroduodenoscopy screening: A retrospective study based on propensity score matching

Background

Esophagogastroduodenoscopy (EGD) screening is vital for the early diagnosis of esophageal squamous cell cancer (ESCC). However, improvement in the detection rate of precancerous lesions and early ESCC with anesthesia assistance (AA) has not yet been investigated. This retrospective study aimed to evaluate the effect of AA on the detection rate of precancerous lesions and early ESCC in patients undergoing EGD screening and identify risk factors affecting the detection rate.

Methods

We reviewed patients' electronic medical records who underwent EGD screening between May 2019 and August 2020. Patients were divided into two groups based on whether they received AA: those in Group A underwent EGD screening with AA, and patients in Group O underwent EGD screening without AA. Propensity score matching (PSM) was used to account for differences in baseline characteristics. Detection rates of precancerous lesions and early ESCC were compared between the two groups following PSM. Binary logistic regression was used to identify risk factors affecting the detection rate.

Results

The final analysis included 21,835 patients (Group A = 13,319, Group O = 8,516) from 28,985 patients who underwent EGD screening during the study period. Following PSM, 6009 patients remained in each group for analysis. There was no significant difference in the detection rate of precancerous lesions and early ESCC between Groups A and O (1.1% vs. 0.8%, p > 0.05). Binary logistic regression showed that age (50-59 years, 60-69 years and 70-79 years), higher endoscopist seniority, high-definition (HD) endoscopy, narrow-band imaging (NBI), and number of endoscopic images were all independent risk factors that affected the detection rate of precancerous lesions and early ESCC.

Conclusion

There was no statistically significant difference in the detection rate of precancerous lesions and early ESCC between patients who underwent EGD screening with and without AA. All independent risk factors that affected the detection rate of precancerous lesions and early ESCC included the following: age (50-59 years, 60-69 years and 70-79 years), higher endoscopist seniority, HD endoscopy, NBI, and number of endoscopic images. Endoscopists should consider all these factors as much as possible when performing EGD screening.

Usefulness of artificial intelligence in early gastric cancer

Gastric cancer (GC) is a major cancer worldwide, with high mortality and morbidity. Endoscopy, important for the early detection of GC, requires trained skills, high-quality technologies, surveillance and screening programs. Early diagnosis allows a better prognosis, through surgical or curative endoscopic therapy. Magnified endoscopy with virtual chromoendoscopy remarkably improve the detection of early gastric cancer (EGC) when endoscopy is performed by expert endoscopists. Artificial intelligence (AI) has also been introduced to GC diagnostics to increase diagnostic efficiency. AI improves the early detection of gastric lesions because it supports the non-expert and experienced endoscopist in defining the margins of the tumor and the depth of infiltration. AI increases the detection rate of EGC, reduces the rate of missing tumors, and characterizes EGCs, allowing clinicians to make the best therapeutic decision, that is, one that ensures curability. AI has had a remarkable evolution in medicine in recent years, moving from the research phase to clinical practice. In addition, the diagnosis of GC has markedly progressed. We predict that AI will allow great evolution in the diagnosis and treatment of EGC by overcoming the variability in performance that is currently a limitation of chromoendoscopy.

Photoacoustic imaging of fresh human surgically and endoscopically resected gastrointestinal specimens

Objective

Photoacoustic (PA) imaging is a novel noninvasive technique that offers high‐contrast tomographic imaging with ultrasound‐like resolution at depths of centimeters, enabling visualization of deep small vessels. The aim of this pilot study was to survey the characteristics of deep vessel networks in the mucosa of neoplastic gastrointestinal (GI) lesions using PA imaging.

Methods

Specimens of patients who had undergone surgical and endoscopic resection for GI lesions were included in this study. The PA/ultrasound imaging system for clinical research is characterized by a technology that can superimpose a PA image over an ultrasound image. Three‐dimensional PA images were acquired for the resected specimen before fixation. The stomach and colon of live pigs were incised, and the walls were scanned from the mucosa.

Results

A total of 32 specimens (nine esophageal, 12 gastric, 11 colorectal) were scanned. The pathological diagnoses were adenomas (n = 2), intramucosal cancers (n = 14), and invasive cancers (n = 16). The deep vessel networks of all lesions could be visualized. In the intramucosal lesions, the deep vessel network was similar to that of a normal tissue. In invasive cancers, the thick and prominent vessel network was visible in the surface layer of esophageal cancers, infiltrated area of gastric cancers, and surface layer and infiltrated area of colorectal cancers. In the images of living pigs, visualizing the vascular network deeper than the submucosa in both the stomach and large intestine was possible.

Conclusion

Our study confirmed that the deep vessel networks of neoplastic GI lesions were visible by PA imaging.

Hesitate between confocal laser endomicroscopy and narrow-band imaging: how to choose a better method in the detection of focal precancerous state of gastric cancer

BACKGROUND

With a high incidence globally, deaths form gastric cancer (GC) are not rare. Early diagnosis is crucial to ameliorate its prognosis. Confocal laser endomicroscopy (CLE) and narrow band imaging (NBI) have been extensively applied in gastroscopy, particularly when it comes to the detection and management of premalignant gastric lesion. Our meta-analysis intends to appraise the diagnostic capability and compare the efficacy of NBI and CLE for focal precancerous state of gastric cancer.

METHODS

We performed a literature search up to November 5, 2020 in online databases and major conferences. Two investigators assessed the methodological bias by QUADAS-2, followed by sophisticated study selection and data exaction to make a comparison between sensitivity, specificity, positive and negative likelihood values, and diagnostic odds ratio. A symmetric summary receiver-operating curve (sROC) and its area under the curve (AUC) were used to estimate threshold effect. Additionally, we evaluated the publication bias by Deeks' asymmetry test.

RESULTS AND CONCLUSIONS

Four studies involved 248 patients and 526 lesions. In analysis drawn from every lesion, the NBI's pooled sensitivity and specificity were 87% (95% CI: 0.80-0.92) and 85% (95% CI: 0.75-0.91), and those of CLE were 90% (95% CI: 0.85-0.91) and 87% (95% CI: 0.83-0.91). CLE illustrated that the pooled two were slightly higher than NBI when compared at the level of every lesion. The AUC for NBI and CLE was 0.92 (0.90-0.94) and 0.95 (0.92-0.96), and there might be a threshold effect, according to the shoulder-like distribution of scatter points in the sROC. We did not find obvious publication bias in our meta-analysis.

Endoscopic Classifications of Early Gastric Cancer: A Literature Review

Simple Summary

Throughout the years, endoscopic technologies have advanced to facilitate better assessment of gastric lesions and early detection of gastric cancer. With improvements in conventional white light endoscopy, we have also witnessed the development of newer endoscopic diagnostic modalities, giving rise to several classifications for early gastric cancer. Different endoscopic classifications of early gastric based on several endoscopic diagnostic modalities were included in this review. In addition to this, newer and novel endoscopic classifications that were specifically developed for the stomach for assessing and diagnosing gastric lesions have also been included. Illustrative representations of each classification have also been provided to aid readers in better understanding of these endoscopic classifications of early gastric cancer.

Abstract

Endoscopic technologies have been continuously advancing throughout the years to facilitate improvement in the detection and diagnosis of gastric lesions. With the development of different endoscopic diagnostic modalities for EGC, several classifications have been advocated for the evaluation of gastric lesions, aiming for an early detection and diagnosis. Sufficient knowledge on the appearance of EGC on white light endoscopy is fundamental for early detection and management. On the other hand, those superficial EGC with subtle morphological changes that are challenging to be detected with white light endoscopy may now be clearly defined by means of image-enhanced endoscopy (IEE). By combining magnifying endoscopy and IEE, irregularities in the surface structures can be evaluated and highlighted, leading to improvements in EGC diagnostic accuracy. The main scope of this review article is to offer a closer look at the different classifications of EGC based on several endoscopic diagnostic modalities, as well as to introduce readers to newer and novel classifications, specifically developed for the stomach, for the assessment and diagnosis of gastric lesions.

MiR-200b Suppresses Gastric Cancer Cell Migration and Invasion by Inhibiting NRG1 through ERBB2/ERBB3 Signaling

Purpose

Accumulating evidence indicates that miRNAs (miRs) play crucial roles in the modulation of tumors development. However, the accurately mechanisms have not been entirely clarified. In this study, we aimed to explore the role of miR-200b in the development of gastric cancer (GC).

Methods

Western blot and RT-PCR were applied to detect epithelial-mesenchymal transition (EMT) marker expression and mRNA expression. Transwell assay was used for measuring the metastasis and invasiveness of GC cells. TargetScan system, luciferase reporter assay, and rescue experiments were applied for validating the direct target of miR-200b.

Results

MiR-200b was prominently decreased in GC tissues and cells, and its downregulation was an indicator of poor prognosis of GC patients. Reexpression of miR-200b suppressed EMT along with GC cell migration and invasion. Neuregulin 1 (NRG1) was validated as the target of miR-200b, and it rescued miR-200b inhibitory effect on GC progression. In GC tissues, the correlation of miR-200b with NRG1 was inverse.

Conclusion

MiR-200b suppressed EMT-related migration and invasion of GC through the ERBB2/ERBB3 signaling pathway via targeting NRG1.

Comparison of the diagnostic efficacy of blue laser imaging with narrow band imaging for gastric cancer and precancerous lesions: a meta-analysis

BACKGROUND AND AIMS

novel endoscopic techniques including narrowband imaging (NBI) and blue laser imaging (BLI) have led to the improved detection of early stage gastric cancer and precancerous lesions. However, these techniques are not generally thought to be equivalent at present and BLI is generally considered as superior to NBI. Therefore, this comprehensive meta-analysis aimed to definitively compare the diagnostic efficacy of NBI and BLI for the diagnosis of gastric cancer and precancerous lesions.

METHODS

relevant articles were identified via searches of the PubMed, Web of Science, Embase and Cochrane Library databases from their inception until October 2019. In total, 28 relevant studies were identified and incorporated into the meta-analysis. RevMan5.3 was used to assess the relative diagnostic efficacy of these two imaging modalities in these studies. The threshold was assessed using Meta-DiSc 1.4 and STATA 14.0 for bivariate regression modeling of pooled studies.

RESULTS

the pooled sensitivity of BLI for gastric cancer was 0.89 (0.80, 0.95) and the specificity was 0.92 (0.76, 0.98). The pooled sensitivity of NBI for gastric cancer was 0.83 (0.75, 0.89) and the specificity was 0.95 (0.91, 0.97). The pooled sensitivity of BLI for precancerous lesions was 0.81 (0.71, 0.87) and the specificity was 0.90 (0.80, 0.96). The pooled sensitivity of NBI for precancerous lesions was 0.80 (0.75, 0.85) and the specificity was 0.88 (0.77, 0.94).

CONCLUSIONS

this study showed that both BLI and NBI have a very high diagnostic efficacy for the detection of gastric cancer and precancerous lesions, the sensitivity and specificity of these two approaches were similar.

Primary localized gastric amyloidosis: A scoping review of the literature from clinical presentations to prognosis

Localized gastric amyloidosis (LGA) is a rare disease characterized by abnormal extracellular deposition of amyloid protein restricted to the stomach and it is confirmed by positive results of Congo red staining. Over decades, only a few cases have been reported and studies or research focusing on it are few. Although LGA has a low incidence, patients may suffer a lot from it and require proper diagnosis and management. However, the pathology of LGA remains unknown and no overall review of LGA from its presentations to its prognosis has been published. Patients with LGA are often asymptomatic or manifest atypical symptoms, making it difficult to differentiate from other gastrointestinal diseases. Here, we report the case of a 70-year-old woman with LGA and provide an overview of case reports of LGA available to us. Based on that, we conclude current concepts of clinical manifestations, diagnosis, treatment, and prognosis of LGA, aiming at providing a detailed diagnostic procedure for clinicians and promoting the guidelines of LGA. In addition, a few advanced technologies applied in amyloidosis are also discussed in this review, aiming at providing clinicians with a reference of diagnostic process. With this review, we hope to raise awareness of LGA among the public and clinicians.

Magnifying endoscopy in detecting early gastric cancer: A network meta-analysis of prospective studies

BACKGROUND

Conventional white-light imaging endoscopy (C-WLI) had a significant number of misdiagnosis in early gastric cancer (EGC), and magnifying endoscopy (ME) combined with different optical imaging was more accurate in the diagnosis of EGC. This study aimed to evaluate the accuracy of ME and compare the accuracy of ME with different optical imaging in detecting EGC.

METHODS

A comprehensive literature search was conducted to identify all relevant studies. Pair-wise meta-analysis was conducted to evaluate the accuracy of ME, and Bayesian network meta-analysis was performed to combine direct and indirect evidence and estimate the relative effects.

RESULTS

Eight prospective studies were identified with a total of 5948 patients and 3 optical imaging in ME (ME with WLI (M-WLI), ME with narrow-band imaging (M-NBI), and ME with blue laser imaging (M-BLI)). Pair-wise meta-analysis showed a higher accuracy of ME than C-WLI (OR: 2.97, 95% CI: 1.68∼5.25). In network meta-analysis, both M-NBI and M-BLI were more accurate than M-WLI (OR: 2.56, 95% CI: 2.13∼3.13; OR: 3.13, 95% CI: 1.85∼5.71). There was no significant difference between M-NBI and M-BLI.

CONCLUSION

ME was effective in improving the detecting rate of EGC, especially with NBI or BLI.

Machine learning predicts lymph node metastasis of poorly differentiated-type intramucosal gastric cancer

To construct a machine learning algorithm model of lymph node metastasis (LNM) in patients with poorly differentiated-type intramucosal gastric cancer. 1169 patients with postoperative gastric cancer were divided into a training group and a test group at a ratio of 7:3. The model for lymph node metastasis was established with python machine learning. The Gbdt algorithm in the machine learning results finds that number of resected nodes, lymphovascular invasion and tumor size are the primary 3 factors that account for the weight of LNM. Effect of the LNM model of PDC gastric cancer patients in the training group: Among the 7 algorithm models, the highest accuracy rate was that of GBDT (0.955); The AUC values for the 7 algorithms were, from high to low, XGB (0.881), RF (0.802), GBDT (0.798), LR (0.778), XGB + LR (0.739), RF + LR (0.691) and GBDT + LR (0.626). Results of the LNM model of PDC gastric cancer patients in test group : Among the 7 algorithmic models, XGB had the highest accuracy rate (0.952); Among the 7 algorithms, the AUC values, from high to low, were GBDT (0.788), RF (0.765), XGB (0.762), LR (0.750), RF + LR (0.678), GBDT + LR (0.650) and XGB + LR (0.619). Single machine learning algorithm can predict LNM in poorly differentiated-type intramucosal gastric cancer, but fusion algorithm can not improve the effect of machine learning in predicting LNM.

Image-enhanced endoscopy for gastric preneoplastic conditions and neoplastic lesions: a systematic review and meta-analysis

BACKGROUND : Image-enhanced endoscopy (IEE) improves the accuracy of endoscopic diagnosis. We aimed to assess the value of IEE for gastric preneoplastic conditions and neoplastic lesions. METHODS : Medline and Embase were searched until December 2018. Studies allowing calculation of diagnostic measures were included. Risk of bias and applicability were assessed using QUADAS-2. Subgroup analysis was performed to explore heterogeneity. RESULTS : 44 studies met the inclusion criteria. For gastric intestinal metaplasia (GIM), narrow-band imaging (NBI) obtained a pooled sensitivity and specificity of 0.79 (95 %CI 0.72-0.85) and 0.91 (95 %CI 0.88-0.94) on per-patient basis; on per-biopsy basis, it was 0.84 (95 %CI 0.81-0.86) and 0.95 (95 %CI 0.94-0.96), respectively. Tubulovillous pattern was the most accurate marker to detect GIM and it was effectively assessed without high magnification. For dysplasia, NBI showed a pooled sensitivity and specificity of 0.87 (95 %CI 0.84-0.89) and 0.97 (95 %CI 0.97-0.98) on per-biopsy basis. The use of magnification improved the performance of NBI to characterize early gastric cancer (EGC), especially when the vessel plus surface (VS) classification was applied. Regarding other technologies, trimodal imaging also obtained a high accuracy for dysplasia (sensitivity 0.93 [95 %CI 0.85-0.98], specificity 0.98 [95 %CI 0.92-1.00]). For atrophic gastritis, no specific pattern was noted and none of the technologies reached good diagnostic yield. CONCLUSION : NBI is highly accurate for GIM and dysplasia. The presence of tubulovillous pattern and the VS classification seem to be useful to detect GIM and characterize EGC, respectively. These features should be used in current practice and to standardize endoscopic criteria for other technologies.

Endoscopic acanthosis nigricans appearance: A novel specific marker for diagnosis of low-grade intraepithelial neoplasia

BACKGROUND AND AIM

At present, there is no recognized diagnostic criteria for gastric low-grade intraepithelial neoplasia (LGIN). The purpose of this study was to determine whether an "endoscopic acanthosis nigricans appearance (EANA)" could be a useful endoscopic marker for distinguishing LGIN lesions from peripheral non-neoplastic tissues.

METHODS

A retrospective study was conducted on 638 cases of suspected superficial lesions with endoscopic images from white light endoscopy and magnifying endoscopy combined with narrow band imaging. According to the pathological results of accurate biopsies, those lesions were divided into three groups: a control group, an LGIN group, and an early gastric cancer (EGC) group.

RESULTS

According to the presence of EANAs, the sensitivity, specificity, positive predictive value, and negative predictive value for differentiating between the LGIN and control groups were 24.8%, 97.3%, 78.3%, and 76.6%, respectively. The sensitivity (84.1%) and negative predictive value (92.4%) were significantly improved by combining EANA with types IV-VI pit pattern. The intervening part and mean gray value of glands, representing microsurface features and microvascular variation, were significantly larger or higher in EANA lesions than in the surrounding non-neoplastic mucosa. LGIN with EANA was more likely to be present in lesions of type 0-IIa. In addition, the prevalence of EANAs in EGC was 16.7%.

CONCLUSION

An EANA could be used as an auxiliary indicator for a diagnosis of LGIN in suspected lesions. It could also play a potential assistive role in the diagnosis of EGC lesions.

A protocol of systematic review and meta-analysis of narrow band imaging endoscopy in detection of early gastric cancer

BACKGROUND

Although previous studies have utilized narrow band imaging endoscopy diagnosis (NBIED) in detection of patients with early gastric cancer (EGC), there are still inconsistent results. Thus, this study will explore the accuracy of NBIED in detection of patients with EGC.

METHODS

We propose to perform literature search of potential studies investigating the accuracy of NBIED in detection of patients with EGC in MEDLINE, EMBASE, Cochrane Library, Web of Science, WANGFANG, VIP database and China National Knowledge Infrastructure from the beginning of each database to January 31, 2020 without restrictions to language and publication time. Two authors will independently scrutinize these databases to identify studies that satisfy all predefined eligibility criteria. We will check study quality and analyze outcome data using Quality Assessment of Diagnostic Accuracy Studies tool, and RevMan 5.3 software respectively.

RESULTS

We anticipate the results of this study will afford additional insight into the appraising of the accuracy of NBIED in patients with EGC.

CONCLUSION

The findings of this study will be useful informing diagnostic decisions for the diagnosis of patients with EGC.PROSPERO registration number: PROSPERO CRD42020171053.

The comprehensive upstream transcription and downstream targeting regulation network of miRNAs reveal potential diagnostic roles in gastric cancer

Evidence has shown that miRNAs can be regulated by multiple mechanisms and can participate in tumorigenesis and progression through binding to 3'-UTRs of target mRNAs. The present study identified differentially expressed miRNAs, mRNAs, and TFs by analyzing miRNA-Seq and mRNA-Seq data to construct a TFs/miRNAs/mRNAs regulation network for GC. We found five miRNAs (miR-18a-5p, miR-21-5p, miR-96-5p, miR-182-5p, and miR-196b-5p) that were significantly overexpressed in GC tissues. Clinical analyses indicated that higher miR-21-5p expression was associated with T3 + T4 and stage III + IV. The expression of miR-96-5p, miR-182-5p, and miR-196b-5p were positively correlated with the patients' ages. The five miRNAs had diagnostic efficacy in distinguishing GC from normal tissues. The gene interaction network showed that the five miRNAs were transcriptionally regulated by 11 TFs and negatively regulated 53 mRNA expressions through binding to the 3'-UTRs. Biological pathway analysis suggested that these TFs and target genes were involved in the p53 pathway, epithelial-to-mesenchymal transition, ErbB receptor, mTOR, VEGF, and VEGFR signaling networks. KEGG pathway analysis indicated that these genes were enriched in some cancer-associated pathways, including in GC. The five miRNAs may act as potential diagnostic markers and the TFs/miRNAs/mRNAs network could suggest a regulation mechanism of miRNAs.

Diagnosis and Endoscopic Treatment of Gastrointestinal Stromal Tumors Arising from Esophagus

Aim: The primary purpose of this study was to investigate the diagnosis and endoscopic treatment of gastrointestinal stromal tumors (GISTs) arising from esophagus. Materials and Methods: From January 2013 to December 2017, 16 cases of GISTs of esophagus were retrospectively identified from a total of >3000 GISTs treated in our center. Demographic characteristics, clinical data, endoscopic therapy outcomes, histopathology, and follow-up were analyzed. Results: The mean age of the patients was 53 years (range 35-71 years), mostly female (56.3%). Seven tumors were in the lower esophagus, five in the middle esophagus, and one in the upper esophagus. The most common symptom was abdominal discomfort (8/16; 50.0%), followed by acid reflux (6/16; 37.5%). All of the patients underwent CT scan, gastroscopy, and/or endoscopic ultrasound. Two patients were diagnosed with esophageal GISTs with a preoperative endoscopic biopsy. Tumors were resected completely in all patients by endoscopic surgery. The median operating time was 85 minutes (range 28-153 minutes), and the average tumor size was 11.6 mm (range 6-21 mm). Postoperative histopathology demonstrated esophageal GISTs were positive for CD117 and CD34. The mean length of postoperative hospital stay was 4.7 days (range 2-7 days). The median postoperative follow-up duration was 28 months (range 1-59 months). Conclusion: Endoscopic treatment seems to be safe and effective for tumors size <20 mm in diameter. However, long-term prospective randomized controlled trials are further needed.

Analysis of Long Non-Coding RNA Expression Profile and Functional Study of LOC389332 in Early Gastric Cancer

Background

Long non-coding RNAs (LncRNAs) could potentially function as diagnostic markers for gastric carcinoma. Nevertheless, the expression profile and biological feature of LncRNAs in early gastric cancer (EGC) remains to be explored.

Material/Methods

LncRNA expression microarray analysis was performed on 6 paired EGC tissues. One deregulated LncRNA, LOC389332, was validated using a quantitative reverse-transcription polymerase chain reaction (qRT-PCR) assay using independent tissue samples and cell lines. The Cell Counting Kit-8 (CCK-8) assay and wound healing assay were conducted to evaluate its influences on the proliferation and migration of gastric cancer cells. LncRNA expression microarray and gene ontology (GO) analysis were also performed on the LOC389332 knockdown cell line model to explore the molecular feature of LOC389332 in gastric carcinoma.

Results

The LncRNA expression profiling showed that 72 LncRNAs were significantly differentially expressed in EGC tissues. The results in the validation phase revealed that LOC389332 was remarkably overexpressed in gastric carcinoma tissues, precancerous lesions, and gastric cancer cells. Functional study showed that knockdown of LOC389332 expression could inhibit cell proliferation and migration. LncRNA expression microarray on the LOC389332 knockdown cell line model revealed that 393 mRNAs were differentially expressed. The GO enrichment analysis indicated that the downregulated genes were mainly associated with cell membrane function, signal transmission process, and cell adhesion process.

Conclusions

The LncRNA expression profile between EGC and gastritis tissues was significantly different. LOC389332 was potential non-coding oncogenes in gastric cancer, and it may perform its function through altering cell membrane function, signal transmission, and cell adhesion.

A Rare Case of Local Recurrence Following Curative Endoscopic Submucosal Dissection of Intramucosal Differentiated-Type Gastric Cancer

A 78-year-old man underwent endoscopic submucosal dissection (ESD) of early gastric cancer (EGC) (type 0-IIa) in the anterior wall of the antrum. En bloc resection was achieved. The histopathological examination revealed very well-differentiated tubular adenocarcinoma (tub1) of 30 × 22 mm in size, confined to the mucosa. No lymphovascular invasion or ulceration was observed, and there was no undifferentiated-type component and the margins were tumor-free. Therefore, this lesion fulfilled the eCuraA criteria. Two years after ESD, esophagogastroduodenoscopy revealed an irregular, slightly-depressed lesion within the post-ESD scar. Tubular adenocarcinoma was suspected based on histopathological examination of a biopsy specimen. The tumor was resected by ESD. A histopathological examination revealed well-differentiated tubular adenocarcinoma (tub1) of 6 × 4 mm in size, confined to the mucosa. No lymphovascular invasion was detected and the margins were tumor-free. These findings indicated a curative resection. Recurrence following a curative ESD of an intramucosal differentiated-type EGC which fulfilled the eCuraA criteria is rare. Careful endoscopic observation using magnifying narrow band imaging (NBI) is needed after ESD, even when curative resection is achieved.

Novel long non-coding RNA LINC02532 promotes gastric cancer cell proliferation, migration, and invasion in vitro

BACKGROUND

Long non-coding RNAs (lncRNAs) are a kind of single-stranded RNA of more than 200 nucleotides in length and have no protein-coding function. Amounting studies have indicated that lncRNAs could play a vital role in the initiation and development of cancers, including gastric cancer (GC). Considering the crucial functions of lncRNAs, the identification and exploration of novel lncRNAs in GC is necessary.

AIM

To explore the role of novel lncRNA LINC02532 in GC.

METHODS

The upregulated LINC02532 was identified by processing the GC RNA-Seq data from The Cancer Genome Atlas. The qRT-PCR assay was performed to confirm the expression levels in GC cell lines and tissues. Cell proliferation, migration, and invasion were evaluated by the cell counting kit-8, colony formation, wound healing, and Transwell assays. The miRNAs downregulated in GC and sponged by LINC02532 were identified from and predicted by the data from the Firehose and RNA22 software programs, respectively. The miRNA downstream target genes were obtained from the TargetScan, miRDB, and DIANA online tools. Gene functional enrichment analysis was carried out using the Database for Annotation, Visualization, and Integrated Discovery software in the categories of cellular components, biological processes, molecular functions, and KEGG pathways.

RESULTS

The qRT-PCR assay demonstrated that the LINC02532 expression level was significantly upregulated in the GC cell lines and 52 paired tissues. Kaplan-Meier survival analysis based on The Cancer Genome Atlas data showed that patients with higher LINC02532 expression had poorer prognosis than those with lower LINC02532 expression. The correlation analysis between expression and clinicopathological features revealed that high expression of LINC02532 was associated with a high TNM stage (P = 0.008) and poor differentiation grade (P = 0.023). Functional experiments showed that LINC02532 promoted GC cell proliferation, migration, and invasion. According to the bioinformatics analysis, LINC02532 may act as a ceRNA by sponging downregulated miR-129-5p and miR-490-5p. Target genes of the two miRNAs were selected for further functional enrichment analysis. Importantly, KEGG pathway analysis showed that the genes were mainly involved in transcriptional misregulation in cancer, cell cycle, and TGF-beta, mTOR, and p53 signaling pathways.

CONCLUSION

The present study suggested that LINC02532 acted as an oncogene in GC and may be a promising target for therapy and prognosis management of GC.

Emerging role of long non-coding RNA in the development of gastric cancer

Gastric cancer is a common, worldwide malignancy and has a poor prognosis due to late diagnosis. Long non-coding RNAs (lncRNAs) are a significant subtype of RNA molecules with a length longer than 200 nucleotides (nt) that rarely encode proteins. In recent decades, deregulation of lncRNAs has been shown to be involved in tumorigenesis and tumor progression in various human carcinomas, including gastric cancer. Accumulating evidence has shown that some lncRNAs may function as diagnostic biomarkers or therapeutic targets for gastric cancer. Thus, exploring the specific functions of lncRNAs will help both gain a better understanding of the pathogenesis and develop novel treatments for gastric cancer. In this review, we highlight the expression and functional roles of lncRNAs in gastric cancer, and analyze the potential applications of lncRNAs as diagnostic markers and therapeutic targets.

How to adjust endoscopic findings to histopathological findings of the stomach: a "histopathology-oriented" correspondence method helps to understand endoscopic findings

BACKGROUND

Endoscopic findings have now become nearly as detailed as histopathological findings. Thus, one-to-one correspondence and precise feedback of histopathological findings is very desirable but may be very difficult to accomplish. We describe a systematic process called the Kyoto One-to-One Correspondence Method (the KOTO Method) that allows detailed adjustments of endoscopic findings to match histopathological findings.

METHODS AND RESULTS

By comparing endoscopic and stereoscopic images of the gastric mucosa, we could obtain one-to-one correspondence between endoscopic images and equivalent histology in 44 of 47 fields.

CONCLUSIONS

The histological structure of gastric cancers of the same histological subtype may not be similar. One-to-one correspondence between endoscopic images and gastric mucosal histology (histopathology-oriented correspondence) will improve endoscopic diagnosis and provide more useful information for pathological diagnosis.

The accuracy of magnifying narrow band imaging (ME-NBI) in distinguishing between cancerous and noncancerous gastric lesions: A meta-analysis

BACKGROUND

Previous clinical trials have demonstrated the diagnostic accuracy of magnifying narrow-band (ME-NBI) for gastric cancerous lesions, but the results are inconsistent. The purpose of this meta-analysis is to investigate the accuracy of ME-NBI in distinguishing between cancerous and noncancerous gastric lesions.

METHODS

Systematic literature searches were conducted until October 2016 in PubMed, Embase by 2 independent reviewers. Meta-analysis was performed to calculate the pooled sensitivity, specificity. Two authors independently evaluated studies for inclusion, rated methodological quality, and abstracted relevant data. Meta-analytic method was used to construct summary receiver operating characteristic curves, and pooled sensitivity, specificity were calculated.

RESULTS

Nine studies enrolling 5398 lesions were included. The pooled sensitivity, specificity were 88% (95% confidence interval [CI]: 78-93%), 96% (95% CI: 91-98%), respectively. The area under the curve (AUC) was 0.97. There was a large heterogeneity between the included studies. Studies with lesions ≤ 10 mm still had a high pooled sensitivity of 81% (95% CI: 73-90%) and specificity of 97% (95% CI: 95-100%). Studies which analyzed resected specimens had a sensitivity of 91% (95 CI: 82-99%) and specificity of 88% (95% CI: 83-94%), and studies which analyzed biopsied specimens had a sensitivity of 85% (95 CI: 74-96%) and specificity of 99% (95% CI: 98-99%).

CONCLUSIONS

ME-NBI is highly accurate and consistent to distinguish between gastric cancerous and noncancerous lesions.

The diagnostic value of confocal laser endomicroscopy for gastric cancer and precancerous lesions among Asian population: a system review and meta-analysis

OBJECTIVE

The objective of this study is to evaluate the diagnostic value of confocal laser endomicroscopy (CLE) in detection of gastric cancer (GC), gastric intraepithelial metaplasia (GIM), and gastric intraepithelial neoplasia (GIN) lesions.

METHOD

PubMed, the Cochrane Library, and Wangfang databases were searched to include eligible articles about CLE in detection of gastric lesions. After study selection, quality assessment and data extraction conducted by two reviewers independently, meta-analysis was performed by Meta-Disc 1.4. The pooled sensitivity and specificity was calculated, receiver operating characteristic (ROC) curve was constructed, and the area under ROC curve (AUC) was calculated.

RESULTS

Twenty-three studies evaluating the diagnostic value of CLE were included. For the diagnosis of GC lesions, the pooled sensitivity, specificity, and AUC were 91% (88-94%), 99% (99-99%), and 0.9513, respectively. For the diagnosis of lesions, the pooled sensitivity, specificity, and AUC were 92% (90-94%), 97% (96-98%), and 0.9774, respectively. For the diagnosis of GIN lesions, the pooled sensitivity, specificity and AUC were 81% (75-85%), 98% (97-98%), and 0.9204, respectively.

CONCLUSIONS

CLE can provide an accurate diagnosis with high sensitivity and specificity for GC, GIM, and GIN lesions. The results should be confirmed by well-designed, multi-centered, randomized controlled, and double blinded trials with large samples.

Specific computed virtual chromoendoscopy for detection of peritoneal carcinomatosis: an animal study

BACKGROUND

Detection of an incipient Peritoneal Carcinomatosis (PC) is still challenging, and there is a crucial need for technological improvements in order to diagnose and to treat early this condition. The aim of this study was to create a murine model of incipient PC and to explore the PC with Fujinon Intelligent Chromo Endoscopy (FICE) in order to determine the wavelengths of the white light (WL) spectre that offer the highest contrast between PC nodules and surrounding peritoneum.

METHODS

Eighteen BALB/c mice had intraperitoneal injection of murine colonic cancer CT26 cells. Peritoneal exploration with FICE was performed at different times. For each PC nodule, 1 WL and 10 FICE images were recorded. Each image was then divided into its elementary red, green and blue band images. Depending on the FICE channel, each elementary image corresponds to a specific wavelength of the WL spectre. Through numerical analysis of these images, the value of the nodule and the background peritoneum were obtained, and the contrast value was calculated. Contrast values obtained with the different wavelengths were then compared.

RESULTS

PC grew in all the mice. The number as well as the size of PC nodules was increasingly high depending on the day of exploration. Mean PCI was 1.6 ± 1.2 at day 5, 7.7 ± 2.6 at day 8 and 15.0 ± 7.3 at day 10. A total number of 1805 elementary images of PC nodules were analysed. The wavelength that offered the best contrast between PC nodules and background peritoneum was 460 nm with a mean contrast value of 0.240 ± 0.151 (p < 0.0001).

CONCLUSION

This murine model of incipient PC is effective, reliable and reproducible. A monochromatic light with a wavelength at 460 nm offers the highest contrast between PC nodules and background peritoneum, allowing a better detection of PC.

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.

Improved Detection of Helicobacter pylori Infection and Premalignant Gastric Mucosa Using "Site Specific Biopsy": a Randomized Control Clinical Trial

BACKGROUND

Helicobacter pylori infection and premalignant gastric mucosa can be reliably identified using conventional narrow band imaging (C-NBI) gastroscopy. The aim of our study was to compare standard biopsy with site specific biopsy for diagnosis of H. pylori infection and premalignant gastric mucosa in daily clinical practice.

MATERIALS AND METHODS

Of a total of 500 patients who underwent gastroscopy for investigation of dyspeptic symptoms, 250 patients underwent site specific biopsy using C-NBI (Group 1) and 250 standard biopsy (Group 2). Sensitivity, specificity, and positive and negative predictive values were assessed. The efficacy of detecting H. pylori associated gastritis and premalignant gastric mucosa according to the updated Sydney classification was also compared.

RESULTS

In group 1 the sensitivity, specificity, positive and negative predictive values for predicting H. pylori positivity were 95.4%, 97.3%, 98.8% and 90.0% respectively, compared to 92.9%, 88.6%, 83.2% and 76.1% in group 2. Site specific biopsy was more effective than standard biopsy in terms of both H. pylori infection status and premalignant gastric mucosa detection (P<0.01).

CONCLUSIONS

Site specific biopsy using C-NBI can improve detection of H. pylori infection and premalignant gastric mucosa in daily clinical practice.

Evaluation of the Diagnostic Ability of Optical Enhancement System in Early Gastric Cancer Demarcation

This study aimed to evaluate the utility of optical enhancement (OE) in early gastric cancer demarcation. Twenty lesions of early gastric cancer were examined by PENTAX endoscopy system with OE-1 and OE-2 functions. The areas of tumor demarcation identified by 12 evaluators (6 novice and 6 experienced) were compared to the corresponding correct areas determined by postoperative histopathology findings. The misdiagnosed scores that were the sums of false-positive and false-negative areas were compared. Color of one hundred pixels from the inside of the cancerous area and the outside of the cancerous area was expressed as three-dimensional RGB component vectors. The mean vectors and covariance matrixes were calculated and the Mahalanobis distance, indicative of color differences between two areas, was tested. Comparisons of the misdiagnosed score revealed that OE-1 was preferred over WL-1 for gastric cancer demarcation for all 12 evaluators (p = 0.008) and in novice evaluators (p = 0.026). OE-2 was not significantly different from WL-2 in all cases. OE-1 images gave significantly larger Mahalanobis distances, indicative of color differences, than WL-1 images (p = 0.002). It was demonstrated that the OE Mode 1 has a significant advantage over the white light mode in demarcation of early gastric cancer.

Role of endoscopic ultrasonography in TNM staging of gastric cancer

Gastric cancer is a common malignancy that has a poor prognosis and high mortality. Cancer staging is the optimal method for evaluating prognosis. Endoscopic ultrasonography (EUS) has been considered the first-choice imaging modality for regional staging of gastric cancer because different structural layers of the gastric wall show remarkable differences in their echogenic appearance. However, the results of recent studies about the accuracy of EUS for staging of gastric cancer are contradictory. The aim of this article is to review the role of EUS in preoperative TNM staging of gastric cancer.

Etiology and Prevention of Gastric Cancer

BACKGROUND

Gastric cancer is a heterogeneous malignant disease associated with environmental and genetic predisposing factors. While gastric cancer incidence and mortality fell greatly globally over the past decades, it remains the fourth cause of cancer-related death worldwide. Thus, prevention of gastric cancer is still a major strategy for improvement of gastric cancer prognosis.

SUMMARY

Helicobacter pylori infection has been demonstrated to be a major risk factor for the development of gastric cancer. Unhealthy diet and lifestyle, including high-salt food, smoking and drinking, are able to induce genotypic and phenotypic transformation of gastric epithelial cells. Gene mutations (such as E-cadherin) in stomach epithelial cells are major genetic causes for gastric cancer. The eradication of H. pylori has been demonstrated to be an effective approach for primary prevention of gastric cancer. Increased intake of a diet rich in vegetables and fresh fruits as well as smoking cessation have been shown to reduce the incidence of gastric cancer. The secondary prevention strategy is to screen premalignant gastric lesions by endoscopy. Biomarker tests are also reliable methods to identify gastric precancerous lesions. Endoscopy screening is still the gold standard for diagnosis of gastric cancer.

KEY MESSAGE

H. pylori infection, a diet rich in salted and/or smoked food and red meat, as well as gene mutations are major risk factors for the development of gastric cancer.

PRACTICAL IMPLICATIONS

The eradication of H. pylori is a major primary preventive strategy of gastric cancer. A healthy lifestyle, including increased intake of a diet rich in fruit and vegetables, reduced intake of salted and smoked food and red meat, a reduction of alcohol intake as well as smoking cessation will be effective approaches for the prevention of gastric cancer.

A feasibility study of the use of computed virtual chromoendoscopy for laparoscopic evaluation of peritoneal metastases

BACKGROUND

Detection of an incipient peritoneal carcinomatosis (PC) is still challenging, and there is a crucial need for technological improvements in order to diagnose and to treat early this condition. Fujinon Intelligent Chromo Endoscopy (FICE) is a spectral image processing technology that enhances the contrast of the target tissue. The aim of this study is to investigate the usefulness of FICE system during peritoneal endoscopy and to establish the optimal FICE preset(s) for peritoneal exploration and PC detection.

METHODS

A total of 561 images corresponding to 51 different areas of PC nodules and normal peritoneum were recorded during peritoneal endoscopies (For each area, one white light endoscopy (WLE) image and 10 FICE images). Three groups of 5 evaluators each: senior surgeons, surgical residents and medical students assessed these images. In a first questionnaire, the evaluators gave a score ranging from 1 to 10 to each image, and the three best FICE channels were determined. In a second questionnaire, five criteria were studied specifically: contrast, brightness, vascular architecture, differentiation between organs and detection of PC. The evaluators ranked the WLE and the three best FICE channel images according to these criteria.

RESULTS

The three best FICE channels were channels 6, 2 and 9 with mean scores of 6.21 ± 1.59, 6.17 ± 1.48 and 6.06 ± 1.52, respectively. FICE Channel 2 was superior to WLE and other FICE channels, in terms of contrast (p < 10^-4), visualization of vascular architecture (p < 10^-4), differentiation between organs (p < 10^-4) and detection of PC (p < 10^-4); and ranked first in 38.8, 41.5, 31 and 46.9 % of the cases, respectively.

CONCLUSION

FICE system provides adequate illumination of the abdominal cavity and a unique contrast that enhances the vascular architecture. FICE Channel 2 is the optimal channel for peritoneal exploration and could be a useful tool for the diagnosis of PC during peritoneal explorations.

Dexmedetomidine versus midazolam for sedation during endoscopy: A meta-analysis

Patients undergoing endoscopy frequently require sedation, which commonly includes the administration of midazolam or dexmedetomidine. Previous meta-analyses have mainly focused on comparing the effects of these two drugs in intensive care unit patients. In the present study, randomized controlled trials (RCTs) that compared the sedative and clinical effectiveness of these two drugs in patients undergoing endoscopy were searched in a number of databases. The meta-analysis showed that dexmedetomidine demonstrated a significantly lower rate of respiratory depression and adverse events compared with those presented upon midazolam administration. A significant difference was also observed in the sedation potency of the sedatives. The current controlled data suggest that dexmedetomidine may be an alternative to midazolam in the sedation for endoscopy. However, more high-quality and well-designed studies are required to further evaluate this conclusion.