Comparison of the diagnostic efficacy of white light endoscopy and magnifying endoscopy with narrow band imaging for early gastric cancer: a meta-analysis

The evolving role of endoscopy in the diagnosis of premalignant gastric lesions

Gastric adenocarcinoma is a disease that is often detected late, at a stage when curative treatment is unachievable. This must be addressed through changes in our approach to the identification of patients at increased risk by improving the detection and risk assessment of premalignant changes in the stomach, including chronic atrophic gastritis and intestinal metaplasia. Current guidelines recommend utilising random biopsies in a pathology-led approach in order to stage the extent and severity of gastritis and intestinal metaplasia. This random method is poorly reproducible and prone to sampling error and fails to acknowledge recent advances in our understanding of the progression to gastric cancer as a non-linear, branching evolutionary model. Data suggest that recent advances in endoscopic imaging modalities, such as narrow band imaging, can achieve a high degree of accuracy in the stomach for the diagnosis of these premalignant changes. In this review, we outline recent data to support a paradigm shift towards an endoscopy-led approach to diagnosis and staging of premalignant changes in the stomach. High-quality endoscopic interrogation of the chronically inflamed stomach mucosa, supported by targeted biopsies, will lead to more accurate risk assessment, with reduced rates of under or missed diagnoses.

Reevaluation of laparoscopic versus open distal gastrectomy for early gastric cancer in Asia: A meta-analysis of randomized controlled trials

BACKGROUND

The benefits and risks of laparoscopic distal gastrectomy (LADG) are not yet sufficiently clear for acceptance as a standard treatment of early gastric cancer. Previous meta-analyses were not powered to reach definitive conclusions.

MATERIALS AND METHODS

Randomized controlled trials comparing LADG with open distal gastrectomy (ODG) for early gastric cancer in Asia and published between January 1994 and January 2018 were retrieved from PubMed, Embase, the Cochrane Library, and Google Scholar. Patient characteristics, oncological safety and efficacy, and surgical safety were evaluated following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Grading of Recommendations Assessment, Development and Evaluation guidelines (GRADE) guidelines. Trial Sequential Analysis (TSA) reduced random error and reinforced the reliability and strength of evidence.

RESULTS

Eight trials including 2666 participants were selected. LADG benefits were an 11.6 cm shorter incision (95% CI: -13.31 to -9.88 cm; P < 0.0001), 103.81 ml less blood loss (95% CI: -133.68 to -73.94; P < 0.0001), 1.73 times less analgesic use (95% CI: -2.21 to -1.24; P < 0.0001), 0.51 days shorter time to first flatus (95% CI: -0.88 to -0.15 days; P = 0.006), lower risk of wound dehiscence (RR = 0.24, 95% CI: 0.08-0.78; P = 0.02), lower risk of surgical adverse events (RR = 0.69, 95% CI: 0.53-0.91; P = 0.008), and lower risk of respiratory complications (RR = 0.40; 95% CI: 0.20-0.79; P = 0.009) than ODG. LADG had 2.22 fewer resected lymph nodes (95% CI: -4.33 to -0.12; P = 0.04) and 76.61 min longer procedures (76.61 min, 95% CI: 57.74-95.47 min; P < 0.0001).

CONCLUSIONS

In Asian patients, LADG had similar mortality and oncological safety, better surgical safety, less operative morbidity, less trauma, and faster recovery than ODG. It has a high role to play in node-negative cases due to better short-term outcomes but less nodal harvest. It is a recommended alternative treatment for experienced surgeons in high-volume centers.

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.

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.

Endoscopic Management of Early Gastric Adenocarcinoma and Preinvasive Gastric Lesions

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

Role of targeted biopsy under magnifying endoscopy with narrow band imaging may be not necessary: a prospective diagnostic accuracy study

BACKGROUND AND AIMS

Targeted biopsy under the guidance of magnifying endoscopy with narrow band imaging (ME-NBI) has higher accuracy than endoscopic forceps biopsy (EFB) in the differential diagnosis of cancerous lesions from noncancerous lesions. The aims of this study were to validate diagnostic efficacy of targeted biopsy under the guidance of ME-NBI (MNTB) and further evaluate whether it is necessary to perform MNTB when combined with ME-NBI.

METHODS

This study prospectively analyzed 211 gastric lesions of suspected cancerous tissues. The sensitivity, specificity, positive predictive value, and negative predictive value of EFB, ME-NBI, MNTB, EFB plus ME-NBI, and MNTB plus ME-NBI for the diagnosis of cancerous lesions were determined, respectively. The accuracy, sensitivity, specificity of EFB and MNTB, EFB plus ME-NBI, and MNTB plus ME-NBI were also compared, respectively.

RESULTS

The accuracy, sensitivity, and specificity with 95% confidence intervals were 68.2% (61.4-74.4%), 62.3% (54.1-69.9%), 84.2% (71.6-92.1%) for EFB, 75.4% (68.9-80.9%), 72.7% (64.9-79.4%), 82.5% (69.6-90.8%) for MNTB, 76.8% (70.4-82.2%), 73.4% (65.5-80.0%), 86.0% (73.7-93.3%) for ME-NBI, 82.0% (76.0-86.8%), 85.7% (79.0-90.6%), 71.9% (58.3-82.6%) for EFB plus ME-NBI, 84.8% (79.1-89.3%), 89.6% (83.4-93.8%), and 71.9% (58.3-82.6%) for MNTB plus ME-NBI, respectively. The sensitivity of MNTB was significantly higher than that of EFB (P=0.048). There was no significant difference in the sensitivity (P=0.307), specificity (P=1.000), and accuracy (P=0.337) between EFB plus ME-NBI and MNTB plus ME-NBI.

CONCLUSION

Although MNTB has a higher diagnostic efficacy than EFB in the diagnosis of cancerous lesions, it may be not necessary to perform MNTB when combined with ME-NBI.

Per-oral video cholangiopancreatoscopy with narrow-band imaging for the evaluation of indeterminate pancreaticobiliary disease

BACKGROUND AND AIMS

Cholangiopancreatoscopy for evaluating pancreaticobiliary pathology is currently limited by suboptimal optics. The aim of this study was to characterize the operating characteristics of per-oral video cholangiopancreatoscopy with narrow-band imaging (POVCP) findings in indeterminate pancreaticobiliary disease and to describe their association with neoplasia.

METHODS

Data from consecutive patients undergoing POVCP for the evaluation of indeterminate pancreaticobiliary disease at a single tertiary care center were analyzed. Two experienced investigators had previously agreed on POVCP findings and terminology that were documented in endoscopy reports. Endoscopic procedural data from POVCPs performed between January 2006 and April 2015 and clinical data were abstracted from the endoscopic database and electronic medical records. Study endpoints included tissue-proven neoplasia or benign disease with ≥1 year of follow-up.

RESULTS

A total of 109 patients were identified; 13 were excluded because of the presence of stone disease, known pancreaticobiliary malignancy, or presumed benign disease with ≤1 year of follow-up. Most patients (85%) underwent POVCP for biliary disease and 15% underwent POVCP for a pancreatic cause. Tortuous and dilated vessels (P < .001), infiltrative stricture (P < .001), polypoid mass (P = .003), and the presence of fish-egg lesions (P = .04) were found to be significantly associated with neoplasia. The overall POVCP impression had a high sensitivity (85%) and negative predictive value (89%) in assessing for the presence of neoplasia.

CONCLUSIONS

Per-oral video cholangiopancreatoscopy is effective in the evaluation of indeterminate pancreaticobiliary disease. Tortuous and dilated vessels, infiltrative stricture, polypoid mass, and the presence of fish-egg lesions are significantly associated with neoplasia.

Endoluminal Diagnosis of Early Gastric Cancer and Its Precursors: Bridging the Gap Between Endoscopy and Pathology

Although dye-based and image-enhanced endoscopic techniques have revolutionized endoscopic diagnosis, conventional white light endoscopy still plays an important role in the diagnosis of early gastric cancer (EGC) during routine endoscopy. Chromoendoscopy reveals morphological characteristics of the mucosal lesions by enhancing mucosal contrast, while narrow-band imaging (NBI) facilitates detailed evaluation of the vascular architecture and surface features. Positive diagnostic findings of EGC on white light imaging and indigo carmine chromoendoscopy are a sharply demarcated lesion and irregularity in surface morphology or color. Magnifying NBI further improves diagnostic accuracy of white light imaging and chromoendoscopy. We review our approach to the endoscopic diagnosis of (pre-)malignant lesions in the stomach and discuss in detail novel endoscopic microvascular architectural patterns which further leverage diagnostic biopsy yield. We expect that further improvement of endoscopic techniques and correlative studies will close the gap between endoscopy and pathology.

Advanced endoscopic imaging in gastric neoplasia and preneoplasia

Conventional white light endoscopy remains the current standard in routine clinical practice for early detection of gastric cancer. However, it may not accurately diagnose preneoplastic gastric lesions. The technological advancements in the field of endoscopic imaging for gastric lesions are fast growing. This article reviews currently available advanced endoscopic imaging modalities, in particular chromoendoscopy, narrow band imaging and confocal laser endomicroscopy, and their corresponding evidence shown to improve diagnosis of preneoplastic gastric lesions. Raman spectrometry and polarimetry are also introduced as promising emerging technologies.

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.

Evaluation and Management of Gastric Superficial Neoplastic Lesions

Gastric cancer is one of the most common and lethal cancers in the world. In Portugal, it is a major health problem presenting one of the highest incidence rates among European countries. In most Western countries, gastric cancer is generally diagnosed in advanced stages. Nevertheless, with the widespread use of upper endoscopy, gastric superficial neoplastic lesions are being increasingly recognized and diagnosed. However, there are no clear recommendations regarding who should be screened for its presence and only recently guidelines concerning the evaluation and management of these lesions were published. In this review, we summarize the current scientific evidence regarding diagnosis and management of gastric superficial neoplastic lesions. Topics like screening, diagnosis, endoscopic evaluation, management, treatment, pathologic evaluation and follow-up of patients with these lesions are covered and areas of future research are discussed. Whenever possible, evidence-based recommendations are made, and on the other cases expert opinion is presented.

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.

Characteristics of Missed Simultaneous Gastric Lesions Based on Double-Check Analysis of the Endoscopic Image

BACKGROUND/AIMS

The detection of multifocal lesions is important for the successful management of gastric neoplasms. We investigated the characteristics of missed simultaneous lesions and the reason for the missed diagnoses.

METHODS

A total of 140 patients who underwent repeat endoscopy before endoscopic resection between June 2013 and June 2014 were retrospectively reviewed. We classified simultaneous lesions into three groups based on a review of earlier images: group 1, no images of the location of simultaneous lesions were taken; group 2, no corresponding lesion was evident in the previous images; and group 3, simultaneous lesions were visible in the earlier images but a biopsy was not performed.

RESULTS

Simultaneous lesions were found in 12 patients (8.6%) with 13 lesions, comprising 10 dysplasia (76.9%) and three adenocarcinoma (23.1%). Regarding the reasons for missed diagnoses, seven lesions (53.8%) were classified as group 3, five (38.5%) as group 1, and the remaining lesion (7.7%) as group 2. There were no significant differences in the characteristics of the patients with and without simultaneous lesions.

CONCLUSIONS

Lesions disregarded or unnoticed during endoscopic examination were the main reason for missed diagnosis of simultaneous lesions. Endoscopists should consider the possibility of simultaneous lesions and attempt to meticulously evaluate the entire gastric mucosa.

Putative risk factors for postoperative pneumonia which affects poor prognosis in patients with gastric cancer

BACKGROUND AND OBJECTIVES

Several recent studies identified that postoperative infectious complications contribute to recurrence and poor outcome in patients with gastric cancer. This study was designed to investigate the prognostic impact of postoperative pneumonia, and to identify the putative risk factors for its occurrence.

METHODS

We retrospectively analyzed 1,415 consecutive patients who underwent curative gastrectomy for gastric cancer between 1997 and 2013.

RESULTS

A total of 31 (2.2 %) patients developed postoperative pneumonia (Clavien-Dindo classification ≥II). Patients with postoperative pneumonia showed a significantly poorer prognosis than patients without (P < 0.001). Concerning the occurrence of postoperative pneumonia, univariate and multivariate analyses identified older age (≥65 years; P = 0.010; odds ratio [OR] 3.59), lower nutritious status (albumin <3 0; P = 0.029; OR 4.51), advanced stage (pStage ≥II; P = 0.045; OR 2.35), concurrent hypertension (P = 0.042; OR 2.21) and total gastrectomy (P = 0.026; OR 2.42) as independent risk factors.

CONCLUSIONS

Postoperative pneumonia was shown to be associated with long-term poor outcome in patients with gastric cancer. Care should be taken for patients with clinical factors such as older age, lower nutritional status, advanced stage, concurrent hypertension, and total gastrectomy.

Helicobacter pylori associated gastric intestinal metaplasia: Treatment and surveillance

Gastric cancer (GC) is one of the leading causes of cancer related death in the world, particularly in East Asia. According to the Correa’s cancer cascade, non-cardia GC is usually developed through a series of mucosal changes from non-atrophic gastritis to atrophic gastritis (AG), intestinal metaplasia (IM), dysplasia and adenocarcinoma. Atrophic gastritis and IM are therefore generally considered to be pre-neoplastic gastric lesions. Helicobacter pylori (H. pylori) infection is an important initiating and promoting step of this gastric carcinogenesis cascade. Emerging long-term data showed that eradication of H. pylori reduced the risk of subsequent cancer development. It however remains confusing whether eradication of the bacterium in individuals with pre-neoplastic gastric lesions could regress these changes as well as in preventing cancer. Whilst H. pylori eradication could likely regress AG, the presence of IM may be a point of no return in this cascade. Hence, surveillance by endoscopy may be indicated in those with extensive IM or those with incomplete IM, particularly in populations with high GC risk. The optimal interval and the best tool of surveillance endoscopy remains to be determined in future studies.