Magnifying Endoscopy with Narrow Band Imaging of Early Gastric Cancer: Correlation with Histopathology and Mucin Phenotype

Correlation between White Globe Appearance and Clinicopathologic Characteristics in Early Gastric Cancer

Background/Aims

Magnifying endoscopy with narrow-band imaging (ME-NBI) enables the visualization of detailed microsurface (MS) and microvascular (MV) structures in the gastrointestinal tract. White globe appearance (WGA) is a small whitish lesion with a globular shape identified during ME-NBI for early gastric cancer (EGC). This study aimed to investigate the associations between WGA, clinicopathological characteristics, and other ME-NBI findings in patients with EGC.

Methods

The presence or absence of WGA in 122 patients (126 lesions) with an endoscopic diagnosis of EGC who underwent ME-NBI before endoscopic or surgical resection was prospectively collected and retrospectively analyzed. During ME-NBI, the MS and MV patterns and the presence of WGA and white opaque substances (WOS) were investigated. EGC cases were categorized as differentiated or undifferentiated type, and mucosal, submucosal, or advanced.

Results

Of 126 lesions, WGA was observed in 25 (19.8%). WGA was associated with tumor size (≤2 cm [17/63, 27.0%] vs >2 cm [8/63, 12.7%]; p=0.044), histologic type (differentiated type [22/89, 24.7%] vs undifferentiated type [3/37. 8.1%]; p=0.033), and tumor location (upper third [1/11, 9.1%] vs middle third [18/58, 31.0%] and lower third [6/57, 10.5%]; p=0.017). Although WGA was observed more frequently in lesions with an oval/tubular MS pattern, a fine-network MV pattern, and the absence of WOS, the difference was not statistically significant (MS pattern, p=0.358; MV pattern, p=0.212; WOS, p=0.121, respectively).

Conclusions

WGA was associated with small tumor size, differentiated-type histology, and middle-third tumor location, and was more frequently observed in lesions with an oval/tubular MS and fine-network MV patterns and the absence of WOS.

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.

Endoscopic submucosal dissection for early gastric cancer: It is time to consider the quality of its outcomes

Endoscopic resection, particularly endoscopic submucosal dissection (ESD), is widely used as a standard treatment modality for early gastric cancer (EGC) when the risk of lymph node metastasis is negligible. Compared with surgical gastrectomy, ESD is a minimally invasive procedure with additional advantages, such as preservation of the entire stomach and maintenance of the patient's quality of life. However, not all patients achieve curative resection after ESD of EGC. Several patients require surgical gastrectomy after ESD to achieve a curative treatment. Additional surgery after ESD, owing to non-curative resection, places considerable emotional and financial burdens on patients. Recently, as the number of endoscopists performing ESD has increased, the rate of non-curative resection after ESD has increased correspondingly. In order to decrease the non-curative resection rate, as well as determine the ideal rate of non-curative resection after ESD, it is time to consider quality indicators for the outcomes of ESD for EGC.

Endoscopic Resection of Early Gastric Cancer and Pre-Malignant Gastric Lesions

Early gastric cancer comprises gastric malignancies that are confined to the mucosa or submucosa, irrespective of lymph node metastasis. Endoscopic resection is currently pivotal for the management of such early lesions, and it is the recommended treatment for tumors presenting a very low risk of lymph node metastasis. In general, these lesions consist of two groups of differentiated mucosal adenocarcinomas: non-ulcerated lesions (regardless of their size) and small ulcerated lesions. Endoscopic submucosal dissection is the technique of choice in most cases. This procedure has high rates of complete histological resection while maintaining gastric anatomy and its functions, resulting in fewer adverse events than surgery and having a lesser impact on patient-reported quality of life. Nonetheless, approximately 20% of resected lesions do not fulfill curative criteria and demand further treatment, highlighting the importance of patient selection. Additionally, the preservation of the stomach results in a moderate risk of metachronous lesions, which underlines the need for surveillance. We review the current evidence regarding the endoscopic treatment of early gastric cancer, including the short-and long-term results and management after resection.

Update on diagnosis and treatment of early signet-ring cell gastric carcinoma: A literature review

Gastric signet-ring cell gastric carcinoma (GSRC) is an unfavorable subtype of gastric cancer (GC) that presents with greater invasiveness and poorer prognosis in advanced stage than other types of GC. However, GSRC in early stage is often considered an indicator of less lymph node metastasis and more satisfying clinical outcome compared to poorly differentiated GC. Therefore, the detection and diagnosis of GSRC at early stage undoubtedly play a crucial role in the management of GSRC patients. In recent years, technological advancement in endoscopy including narrow-band imaging and magnifying endoscopy has significantly improved the accuracy and sensitivity of the diagnosis under endoscopy for GSRC patients. Researches have confirmed that early stage GSRC that meets the expanded criteria of endoscopic resection showed comparable outcomes to surgery after receiving endoscopic submucosal dissection (ESD), indicating that ESD could be considered standard treatment for GSRC after thorough selection and evaluation. This article summarizes the current knowledge and updates pertaining to the endoscopic diagnosis and treatment of early stage signet-ring cell gastric carcinoma.

Comparison of clinical and pathological features between early-stage gastric-type and intestinal-type differentiated adenocarcinoma: a retrospective study

BACKGROUND

The clinicopathological features and endoscopic characteristics under magnifying endoscopy with narrow band imaging (ME-NBI) between early-stage gastric-type differentiated adenocarcinoma (GDA) and intestinal-type differentiated adenocarcinoma (IDA) remain controversial.

METHODS

Early gastric adenocarcinomas that underwent endoscopic submucosal dissection (ESD) in Nanjing Drum Tower Hospital between August 2017 and August 2021 were included in the present study. GDA cases and IDA cases were selected based on morphology and immunohistochemistry staining of CD10, MUC2, MUC5AC, and MUC6. Clinicopathological data and endoscopic findings in ME-NBI were compared between GDAs and IDAs.

RESULTS

The mucin phenotypes of 657 gastric cancers were gastric (n = 307), intestinal (n = 109), mixed (n = 181) and unclassified (n = 60). No significant difference was observed in terms of gender, age, tumor size, gross type, tumor location, background mucosa, lymphatic invasion, and vascular invasion between patients with GDA and IDA. GDA cases were associated with deeper invasion than IDA cases (p = 0.007). In ME-NBI, GDAs were more likely to exhibit an intralobular loop patten, whereas IDAs were more likely to exhibit a fine network pattern. In addition, the proportion of none-curative resection in GDAs was significantly higher than that in IDAs (p = 0.007).

CONCLUSION

The mucin phenotype of differentiated early gastric adenocarcinoma has clinical significance. GDA was associated with less endoscopically resectability than IDA.

Clinical characteristics and risk factors for upgraded pathology in patients with gastric intraepithelial neoplasia after endoscopic submucosal dissection

BACKGROUND AND AIMS

The pathological results of endoscopic forceps biopsy (EFB) are frequently inconsistent with those after endoscopic submucosal dissection (ESD) in patients with gastric intraepithelial neoplasia (GIN). The aim of this study was to explore the risk factors for upgraded pathology after ESD in the Wannan region of Anhui Province, in order to guide the best clinical treatment of GIN.

METHODS

A retrospective analysis was performed at the First Affiliated Hospital of Wannan Medical College. Univariate analysis and multivariate analysis were used to investigate the independent risk factors for pathology upgrade between EFB and ESD.

RESULTS

In total, 215 patients who were initially diagnosed with GIN from EFB and subsequently received treatment with ESD were eventually selected for analysis. Age >60 years, a lesion located in upper 2/3 of the stomach, a lesion size of >2 cm, a lesion surface with redness and nodules and a lesion with irregular or absent microglands were significantly associated with the upgraded group after ESD. Multivariate analysis suggested that a lesion size of >2 cm (odds ratio [OR], 1.499; 95% confidence interval [CI], 1.222-1.909; P=0.026), a lesion surface with redness (OR, 1.508; 95%CI, 1.260-1.993; P=0.048) and nodules (OR, 1.390; 95%CI, 1.195-1.778; P=0.008) were independent predictors for the upgraded group.

CONCLUSIONS

For patients with suspected GIN by EFB, a lesion size of >2 cm, a lesion surface with redness and nodules should be taken into account before deciding on the ESD.

Endoscopic submucosal dissection for superficial gastrointestinal lesions: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2022

ESGE recommends that the evaluation of superficial gastrointestinal (GI) lesions should be made by an experienced endoscopist, using high definition white-light and chromoendoscopy (virtual or dye-based).ESGE does not recommend routine performance of endoscopic ultrasonography (EUS), computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET)-CT prior to endoscopic resection.ESGE recommends endoscopic submucosal dissection (ESD) as the treatment of choice for most superficial esophageal squamous cell and superficial gastric lesions.For Barrett's esophagus (BE)-associated lesions, ESGE suggests the use of ESD for lesions suspicious of submucosal invasion (Paris type 0-Is, 0-IIc), for malignant lesions > 20 mm, and for lesions in scarred/fibrotic areas.ESGE does not recommend routine use of ESD for duodenal or small-bowel lesions.ESGE suggests that ESD should be considered for en bloc resection of colorectal (but particularly rectal) lesions with suspicion of limited submucosal invasion (demarcated depressed area with irregular surface pattern or a large protruding or bulky component, particularly if the lesions are larger than 20 mm) or for lesions that otherwise cannot be completely removed by snare-based techniques.ESGE recommends that an en bloc R0 resection of a superficial GI lesion with histology no more advanced than intramucosal cancer (no more than m2 in esophageal squamous cell carcinoma), well to moderately differentiated, with no lymphovascular invasion or ulceration, should be considered a very low risk (curative) resection, and no further staging procedure or treatment is generally recommended.ESGE recommends that the following should be considered to be a low risk (curative) resection and no further treatment is generally recommended: an en bloc R0 resection of a superficial GI lesion with superficial submucosal invasion (sm1), that is well to moderately differentiated, with no lymphovascular invasion, of size ≤ 20 mm for an esophageal squamous cell carcinoma or ≤ 30 mm for a stomach lesion or of any size for a BE-related or colorectal lesion, and with no lymphovascular invasion, and no budding grade 2 or 3 for colorectal lesions.ESGE recommends that, after an endoscopically complete resection, if there is a positive horizontal margin or if resection is piecemeal, but there is no submucosal invasion and no other high risk criteria are met, this should be considered a local-risk resection and endoscopic surveillance or re-treatment is recommended rather than surgery or other additional treatment.ESGE recommends that when there is a diagnosis of lymphovascular invasion, or deeper infiltration than sm1, or positive vertical margins, or undifferentiated tumor, or, for colorectal lesions, budding grade 2 or 3, this should be considered a high risk (noncurative) resection, and complete staging and strong consideration for additional treatments should be considered on an individual basis in a multidisciplinary discussion.ESGE recommends scheduled endoscopic surveillance with high definition white-light and chromoendoscopy (virtual or dye-based) with biopsies of only the suspicious areas after a curative ESD.

The future of endoscopic resection for early gastric cancer

Endoscopic resection for early gastric cancer is recommended when the risk of lymph node metastasis is negligible and should be performed through submucosal dissection due to well-established short- and long-term results. To overcome technical difficulties and decrease adverse events some techniques have been studied. This review outlines current strategies for improving patient selection and highlights innovative techniques that help minimize adverse events. Moreover, we discuss how to improve management after curative and noncurative resections.

Diagnosis of histological type of early gastric cancer by magnifying narrow‐band imaging: A multicenter prospective study

Objectives

Distinguishing undifferentiated‐type from differentiated‐type early gastric cancers (EGC) is crucial for determining the indication of endoscopic resection. We aimed to investigate the diagnostic performance of white‐light endoscopy (WLE) and magnifying narrow‐band imaging (M‐NBI) for the histological type of EGC.

Methods

In this multicenter prospective study, patients with histologically proven cT1 EGC, macroscopically depressed or flat type, size ≥5 mm, and without erosion/ulcer, were recruited. The diagnostic criterion of WLE for undifferentiated‐type EGC was pale color. The M‐NBI algorithm was created based on microsurface and microvascular patterns, and lesions with absent microsurface pattern and opened‐loop microvascular patterns were diagnosed as undifferentiated‐type. The center of the lesion was defined as the evaluation point and was initially evaluated by WLE, then by M‐NBI, and a biopsy specimen was taken as a reference standard. The primary and key secondary endpoints were overall diagnostic accuracy and specificity, respectively.

Results

In total, 167 lesions (122 differentiated‐type and 45 undifferentiated‐type EGCs) in 167 patients were analyzed. The overall accuracy, sensitivity, specificity, and positive likelihood ratio of WLE for undifferentiated‐type cancer were 80%, 69%, 84%, and 4.4, respectively, and those of M‐NBI were 82%, 53%, 93%, and 7.2, respectively. There was no significant difference in overall accuracy (p = 0.755), but specificity was significantly higher in M‐NBI (p = 0.041).

Conclusions

The use of M‐NBI did not improve the accuracy of WLE for the diagnosis of depressed/flat undifferentiated‐type EGCs but improved the specificity. It may reduce surgical overtreatment by preventing misdiagnosis of differentiated‐type EGC as undifferentiated‐type.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Endoscopic Advances for Gastric Neoplasia Detection

This article explores advances in endoscopic neoplasia detection with supporting clinical evidence and future aims. The ability to detect early gastric neoplastic lesions amenable to curative endoscopic submucosal dissection provides the opportunity to decrease gastric cancer mortality rates. Newer imaging techniques offer enhanced views of mucosal and microvascular structures and show promise in differentiating benign from malignant lesions and improving targeted biopsies. Conventional chromoendoscopy is well studied and validated. Narrow band imaging demonstrates superiority over magnified white light. Autofluorescence imaging, i-scan, flexible spectral imaging color enhancement, and bright image enhanced endoscopy show promise but insufficient evidence to change current clinical practice.

Exploration of an effective training system for diagnosis of superficial esophageal squamous cell carcinoma with magnifying narrow-band imaging: Prospective research

BACKGROUND AND AIMS

The aim was to explore an effective training system for diagnosis of superficial esophageal squamous cell carcinoma (SESCC) and its staging with magnifying narrow-band imaging (M-NBI).

PATIENTS AND METHODS

Fifteen endoscopists with no or less M-NBI experience participated in this training, which consisted of four stages and five teaching methods (M-NBI classification criterion, case analysis, hands-on operation, error correction and SESCC pathological knowledge). M-NBI images were evaluated and diagnostic accuracy was analyzed.

RESULTS

After training, the accuracy of distinguishing neoplastic esophageal from non-neoplastic (0.58 ± 0.16 vs. 0.95 ± 0.05, P = 0.000) and diagnosing SESCC staging (0.25 ± 0.26 vs. 0.89 ± 0.08, P = 0.000) with M-NBI were significantly increased. Participants with no M-NBI experience achieve equivalent diagnostic accuracy with less experienced trainees after the training (0.91 ± 0.08 vs. 0.92 ± 0.04, P = 0.816). Besides, diagnosis of MM (muscularis mucosa)/SM1 (submucosal) staging tumors (Stage I, 0.47 ± 0.15; Stage II-III-IV, 0.76 ± 0.12) with M-NBI was difficult for trainees and should be the focus of this training. Every teaching method could improve the diagnostic accuracy for esophageal lesions, especially for case analysis (from 0.59 ± 0.10 to 0.85 ± 0.08, P = 0.000). In addition, the average operation score for trainees was significantly increased after hands-on teaching (60.40 ± 11.11 vs. 91.80 ± 4.28, P = 0.0001).

CONCLUSIONS

For novices, this training system showed efficient performance for diagnosing SESCC staging with M-NBI. Diagnosing MM/SM1 staging SESCC was difficult for beginners, and should be the focus of training.

Image-Enhanced Endoscopy and Its Corresponding Histopathology in the Stomach

In recent years, the technological innovation and progress of endoscopic equipment have been remarkable, and various endoscopic observation techniques have been developed. Among them, representative techniques are magnified observation and narrow-band imaging. Magnifying endoscopy with narrow-band imaging (M-NBI) can visualize superficial microanatomies in the stomach. The normal morphology of the microanatomy visualized using M-NBI differs according to the part of the stomach. The vessel plus surface (VS) classification system has been developed as a diagnostic criterion for early gastric cancer using M-NBI, and its usefulness has been proven. Based on the VS classification system, a magnifying endoscopy simple diagnostic algorithm for early gastric cancer (MESDA-G), a simplified algorithm used for early gastric cancer diagnosis, was created. We aimed to describe the anatomic structure of the stomach that can be viewed using M-NBI and outline the principles and clinical application of the VS classification system and MESDA-G. (Gut Liver 2021;15:-337)

Narrowband imaging with near-focus magnification for discriminating the gastric tumor margin before endoscopic resection: A prospective randomized multicenter trial

BACKGROUND AND AIM

This study investigated the usefulness of near-focus narrowband imaging (NF-NBI) for determining gastric tumor margins compared with indigo carmine chromoendoscopy (ICC) before endoscopic submucosal dissection (ESD).

METHODS

This prospective randomized controlled trial was conducted at seven teaching hospitals in Korea. Patients with gastric adenoma or differentiated adenocarcinoma undergoing ESD were enrolled and randomly assigned to the NF-NBI or ICC group. A marking dot was placed on the most proximal margin of the tumor before ESD. The primary endpoint was delineation accuracy, which was defined as presence of marking dots within 1 mm of the tumor margin under microscopic observation.

RESULTS

A total of 200 patients in the NF-NBI group and 195 patients in the ICC group were included. The delineation accuracy rate was 84.5% in the NF-NBI group and 81.0% in the ICC group (P = 0.44). However, the distance from the marking dot to the margin of the tumor was significantly shorter in the NF-NBI group than in the ICC group (0.8 ± 0.8 vs 1.2 ± 1.3 mm, P < 0.01). Even after adjustment of other clinicopathological factors that are associated with difficulty of tumor delineation, NF-NBI did not show significant association with accurate delineation (odds ratio of 0.86, P = 0.60).

CONCLUSIONS

This prospective multicenter study showed that NF-NBI is not superior to ICC in terms of accurately delineating gastric tumors (NCT02661945).

Clinicopathologic Characteristics and Risk Factors of Lymph Node Metastasis in Patients with Early Gastric Cancer in the Wannan Region

BACKGROUND To date, there has been no agreement on the risk factors of lymph node metastasis (LNM) for early gastric cancer (EGC). The objective of this article was to investigate the risk factors of LNM in EGC in the Wannan region of Anhui Province and then to develop a regional practice guideline to manage EGC cases in this population. MATERIAL AND METHODS This retrospective analysis was performed from July 1, 2014 to June 30, 2017, at First Affiliated Hospital of Wannan Medical College. We explored the independent risk factors of LNM by using univariate analysis and multivariate analysis. RESULTS In total, 381 patients were selected for analysis. The LNM rate of EGC was 13.65% (52 out of 381 patients). Submucosal invasion, ulcer presence, undifferentiated tumor, vascular tumor thrombus, and neural invasion were significantly associated with LNM in EGC patients. Multivariate analysis suggested that depth of invasion (odds ratio [OR], 3.50; 95% confidence interval [CI], 1.45-8.42; P=0.005), vascular tumor thrombus (OR, 6.33; 95%CI, 2.31-17.31; P=0.001), and neural invasion (OR, 10.95; 95%CI, 3.29-36.41; P=0.001) were independent predictors of LNM in EGC patients CONCLUSIONS In the Wannan region of Anhui Province in China, depth of invasion, vascular tumor thrombus, and neural invasion were independent predictive risk factors for LNM in EGC patients. EGC patients with these risk factors for LNM are more likely to have LNM, and radical surgical procedure was more likely to be considered. With respective to EGC with submucosal invasion, the flat type pattern had a lower risk of LNM.

Gastric endoscopic submucosal dissection: a systematic review and meta-analysis on risk factors for poor short-term outcomes

OBJECTIVE

Endoscopic submucosal dissection (ESD) is now established as the first option to manage early gastric neoplasms, but its efficacy may vary according to diverse factors. We aimed to systematically identify risk factors for poor short-term outcomes of gastric ESD with the purpose to improve patients' selection and management.

METHODS

Three online databases (MEDLINE, ISI Web of Knowledge and Scopus) were searched (last search on June 2018) for poor outcomes of gastric ESD (deep submucosal invasion, piecemeal/incomplete resection, noncurative resection and local recurrence).

RESULTS

One hundred five studies were included referring to 52.126 ESDs. Undifferentiated histology and upper location (vs lower) were associated with submucosal invasion [odds ratio (OR) = 2.42 [95% confidence interval (CI), 1.62-3.61] and OR = 3.20 (1.04-9.86), respectively] and deep submucosal invasion [OR = 2.98 (2.02-4.39) and OR = 2.35 (1.45-3.81), respectively]. Lesion size greater than 30 mm and ulceration were associated with piecemeal resection [OR = 2.78 (1.17-6.60) and OR = 2.76 (1.23, 6.20), respectively]. Lesion size greater than 30 mm, ulceration, upper location and fibrosis were risk factors for incomplete resection [OR = 3.83 (2.68-5.49), OR = 4.06 (1.62-10.16), OR = 3.71 (2.49-5.54) and OR = 4.46 (1.66-11.96), respectively]. A noncurative resection was more often observed for lesions located in the upper third of the stomach [OR = 1.49 (1.24-1.79)], depressed morphology [OR = 1.49 (1.04-2.12)] and those outside standard criteria [OR = 3.56 (2.31-5.48)]. Older age was significantly linked with local recurrence rates [OR = 3.08 (1.13-5.02)].

CONCLUSION

Several risk factors influence poor efficacy short-term outcomes of gastric ESD that may be used to inform both patients and health providers about the expected efficacy.

A meta-analysis of narrow-band imaging for the diagnosis of primary nasopharyngeal carcinoma

Background: Narrow band imaging (NBI), an endoscopic technique featuring an augmented definition of microvasculature and mucosal patterns. NBI is increasingly advocated as a tool to characterize neoplasia and intestinal metaplasia in endoscopic standards, such as for colorectal polyps and tumors. Recently NBI has also been studied in the detection of Nasopharyngeal Carcinoma (NPC). Here we aimed to assess the diagnostic utility of NBI for the diagnosis of NPC. Methods: A meta-analysis of studies comparing narrow-band imaging and white light endoscopy in the diagnosis of primary nasopharyngeal carcinoma was performed. The review process involved two independent investigators. The databases used were MEDLINE, PubMed, the Cochrane library, Embase, and the Web of Science. Statistical analysis was performed with OpenMetaAnalyst, MetaDiSc version 1.4, and Medcalc version 17.9.7.  Results: Five studies including 2480 patients were included. The sensitivity and specificity for narrow-band imaging were 0.90 (0.73-0.97) and 0.95 (0.81-0.99) respectively. The positive likelihood ratio and negative likelihood ratio were 18.82 (0.31-82.1) and 0.08 (0.02-0.31). For white light endoscopy, the sensitivity and specificity were 0.77 (0.58-0.89) and 0.91 (0.79-0.96). The positive likelihood ratio was 7.61 (3.61-16.04), and the negative likelihood ratio was 0.21 (0.11-0.39). The odds ratio for detection rates between narrow-band imaging and white light endoscopy was 4.29 (0.56-33.03, p = 0.16). Area under the curve for narrow-band imaging was 0.98 (SE: 0.02), and for white light it was 0.93 (SE: 0.03). There was no significant difference in the receiver operating characteristic curves between the two modalities (p = 0.14). Conclusion: Narrow-band imaging showed a higher sensitivity and positive likelihood ratio for the diagnosis of nasopharyngeal carcinoma. However, there was no significant difference in detection rates compared to white light endoscopy. Further investigation with a uniform diagnostic criteria and terminology is needed for narrow-band imaging in the diagnosis of nasopharyngeal carcinoma.

Narrow-Band Imaging: Clinical Application in Gastrointestinal Endoscopy

Narrow-band imaging is an advanced imaging system that applies optic digital methods to enhance endoscopic images and improves visualization of the mucosal surface architecture and microvascular pattern. Narrow-band imaging use has been suggested to be an important adjunctive tool to white-light endoscopy to improve the detection of lesions in the digestive tract. Importantly, it also allows the distinction between benign and malignant lesions, targeting biopsies, prediction of the risk of invasive cancer, delimitation of resection margins, and identification of residual neoplasia in a scar. Thus, in expert hands it is a useful tool that enables the physician to decide on the best treatment (endoscopic or surgical) and management. Current evidence suggests that it should be used routinely for patients at increased risk for digestive neoplastic lesions and could become the standard of care in the near future, at least in referral centers. However, adequate training programs to promote the implementation of narrow-band imaging in daily clinical practice are needed. In this review, we summarize the current scientific evidence on the clinical usefulness of narrow-band imaging in the diagnosis and characterization of digestive tract lesions/cancers and describe the available classification systems.

Magnifying endoscopy with narrow-band imaging for gastric heterotopic pancreas

BACKGROUND AND STUDY AIMS

 Heterotopic pancreas is a common subepithelial lesion in the stomach. However, its histological diagnosis is difficult when tissue samples are obtained with a conventional biopsy forceps. This study aimed to describe the magnifying endoscopy with narrow-band imaging (ME-NBI) features of gastric heterotopic pancreas.

PATIENTS AND METHODS

 We retrospectively analyzed a database of all patients who underwent endoscopic ultrasonography (EUS) at Pusan National University Hospital from January 2010 to December 2010. Thirty-six patients with endosonographically diagnosed heterotopic pancreas who underwent ME-NBI and endoscopic ultrasonography (EUS) simultaneously were studied. The ME-NBI features of their lesions were analyzed.

RESULTS

 Thirty lesions were located in the antrum and six in the body. Six lesions (17 %) showed umbilication or central dimpling on the surface, and nine (25 %) had a macroscopic opening on the surface. On ME-NBI, a microscopic opening was identified in 22 (81 %) of 27 lesions wherein a macroscopic opening was not observed during conventional endoscopy. Macroscopic or microscopic opening was observed in 31 lesions (86 %). The frequency of macroscopic or microscopic opening was higher in lesions with anechoic duct-like structures than in lesions without such structures on EUS (91 % [29/32] vs 50 % [2/4], P  = 0.027). Focal loss of microsurface structure and presence of a thickened submucosal vessel were observed in 6 (17 %) and 5 lesions (14 %), respectively.

CONCLUSIONS

The characteristic ME-NBI feature of heterotopic pancreas is presence of a microscopic opening on its surface. This ME-NBI feature is potentially useful for differentiating heterotopic pancreas from other gastric subepithelial tumors.

Evaluation and management of gastric epithelial polyps

Gastric polyps include a wide spectrum of lesions with different histology and neoplastic potential. They are found in up to 6% of upper gastrointestinal endoscopy and are usually asymptomatic and incidentally diagnosed, being in the vast majority epithelial gastric polyps. Hyperplastic, fundic gland and adenomas are the most common types of gastric polyps and, although each type may have typical endoscopic appearances, they all must be sampled at the initial endoscopy for histological assessment. Also, the normal appearing gastric mucosa should be sampled to stage atrophic changes, rule out endoscopically non-visible dysplasia and to diagnose Helicobacter pylori. Polyposis syndromes that affect the stomach are rare but should be taken into account. Hamartomatous polyps can be found in Juvenile polyposis, Cowden syndrome and Peutz-Jeghers syndrome. On the other hand, multiple fundic gland polyps are present in the majority of patients with familial adenomatous polyposis. In this study we provide a comprehensive review on the evaluation and management of gastric epithelial polyps, in this way helping physicians to properly handle this type of lesions.