A cohort study of missed and new cancers after esophagogastroduodenoscopy

The value of machine learning approaches in the diagnosis of early gastric cancer: a systematic review and meta-analysis

BACKGROUND

The application of machine learning (ML) for identifying early gastric cancer (EGC) has drawn increasing attention. However, there lacks evidence-based support for its specific diagnostic performance. Hence, this systematic review and meta-analysis was implemented to assess the performance of image-based ML in EGC diagnosis.

METHODS

We performed a comprehensive electronic search in PubMed, Embase, Cochrane Library, and Web of Science up to September 25, 2022. QUADAS-2 was selected to judge the risk of bias of included articles. We did the meta-analysis using a bivariant mixed-effect model. Sensitivity analysis and heterogeneity test were performed.

RESULTS

Twenty-one articles were enrolled. The sensitivity (SEN), specificity (SPE), and SROC of ML-based models were 0.91 (95% CI: 0.87-0.94), 0.85 (95% CI: 0.81-0.89), and 0.94 (95% CI: 0.39-1.00) in the training set and 0.90 (95% CI: 0.86-0.93), 0.90 (95% CI: 0.86-0.92), and 0.96 (95% CI: 0.19-1.00) in the validation set. The SEN, SPE, and SROC of EGC diagnosis by non-specialist clinicians were 0.64 (95% CI: 0.56-0.71), 0.84 (95% CI: 0.77-0.89), and 0.80 (95% CI: 0.29-0.97), and those by specialist clinicians were 0.80 (95% CI: 0.74-0.85), 0.88 (95% CI: 0.85-0.91), and 0.91 (95% CI: 0.37-0.99). With the assistance of ML models, the SEN of non-specialist physicians in the diagnosis of EGC was significantly improved (0.76 vs 0.64).

CONCLUSION

ML-based diagnostic models have greater performance in the identification of EGC. The diagnostic accuracy of non-specialist clinicians can be improved to the level of the specialists with the assistance of ML models. The results suggest that ML models can better assist less experienced clinicians in diagnosing EGC under endoscopy and have broad clinical application value.

Current status of quality control in screening esophagogastroduodenoscopy and the emerging role of artificial intelligence

Esophagogastroduodenoscopy (EGD) screening is being implemented in countries with a high incidence of upper gastrointestinal (UGI) cancer. High-quality EGD screening ensures the yield of early diagnosis and prevents suffering from advanced UGI cancer and minimal operational-related discomfort. However, performance varied dramatically among endoscopists, and quality control for EGD screening remains suboptimal. Guidelines have recommended potential measures for endoscopy quality improvement and research has been conducted for evidence. Moreover, artificial intelligence offers a promising solution for computer-aided diagnosis and quality control during EGD examinations. In this review, we summarized the key points for quality assurance in EGD screening based on current guidelines and evidence. We also outline the latest evidence, limitations, and future prospects of the emerging role of artificial intelligence in EGD quality control, aiming to provide a foundation for improving the quality of EGD screening.

Post-Endoscopy Upper Gastrointestinal Cancer Rate in a Tertiary Referral Centre: An Australian Data Linkage Analysis

OBJECTIVE

High-quality gastroscopy is critical for early diagnosis of upper gastrointestinal cancers (UGCs), and assessment of missed cancers may serve as a key quality metric. Using a prospective gastroscopy database and data linkage with the Queensland Cancer Registry, we assessed the risk of developing UGC within 3 years of a cancer-negative gastroscopy at an Australian tertiary centre. Additional aims were to identify factors predictive of missed cancer, perform root cause analyses for missed cancers and assess overall survival.

DESIGN/METHOD

We identified patients who were diagnosed with UGC within 3 years of undergoing gastroscopy between 2011 and 2016. Non-mucosal cancers, cancers distal to duodenum and patients undergoing surveillance were excluded. Cases diagnosed within 6 months of gastroscopy were defined as detected cancers, while those developing within 6-36 months were defined as missed cancers. Post-endoscopy UGC rate (PEUGIC-3Y) was calculated as ratio of missed over total cancers detected. Demographic, clinical, endoscopic and histologic variables were analysed.

RESULTS

A total of 17,131 gastroscopies were performed for 10,393 patients during the study period. One hundred and twenty-six UGCs were diagnosed, including 120 detected UGCs and 6 missed UGCs. The overall PEUGIC-3Y rate was 4.8% (95% CI 2.1-10.4). The missed UGCs included 3 gastric adenocarcinomas, 2 gastro-oesophageal junction adenocarcinomas and 1 oesophageal squamous cell carcinoma. At the preceding 'cancer-negative gastroscopy', no macroscopic abnormalities were detected at the site of future UGC in 5/6 patients. A UGC developed in 2/6 patients despite an apparent adequate examination at index gastroscopy. Age, sex, indication for endoscopy and cancer location or histology were not predictive of missed cases, and survival was comparable between groups.

CONCLUSION

We demonstrate that the PEUGIC-3Y rate was 4.8% (95% CI 2.1-10.4). The majority of missed cases were adenocarcinomas of the gastro-oesophageal junction or stomach and developed in segments which were found to be normal at index gastroscopy, highlighting the challenges in detecting subtle mucosal lesions in the upper gastrointestinal tract. While overall survival between patients with detected and post-gastroscopy cancers was comparable, these ultimately represent potential missed opportunities for diagnosing an early cancer and underscore the need for quality improvement in gastroscopy.

Variation in the rate of detection of minute and small early gastric cancers at diagnostic endoscopy may reflect the performance of individual endoscopists

OBJECTIVE

The documented variation in gastric cancer (GC) detection among endoscopists has often been dismissed as a coincidental artefact of the low incidence of gastric neoplasms; it is not considered associated with differences in physicians' performance of the esophagogastroduodenoscopy procedure. This study is to confirm whether significant variations among endoscopists in early GC detection suggest the individual performance of the upper endoscopy.

DESIGN

A retrospective observational study at a single centre in Japan assessed the results of 218 early GCs detected during 25 688 routine esophagogastroduodenoscopies by 12 endoscopists. The main outcome was the rate of early GC detection for each endoscopist under the same circumstances. Other measures included the major diameters and locations of the lesions, Helicobacter pylori infection status, and baseline patient characteristics that could affect the prevalence of GC.

RESULTS

The early GC detection rates exhibited wide variation among endoscopists (0.09%-2.87%) despite performing routine esophagogastroduodenoscopies in a population with a similar background. Endoscopists were assigned to a low-detection group (n=6; detection rate: 0.47% (range: 0.09%-0.55%)) and a high-detection group (n=5; detection rate: 0.83% (range: 0.63%-1.12%)), with the single highest detector analysed separately due to his distinct detection rate (2.87%). Endoscopists in the high-detection group had better detection rates for minute (major diameter ≤5 mm) and small (major diameter 6-10 mm) GCs than the low-detection group (0.19%/0.23% vs 0.085%/0.098%). These differences were significant (p<0.01), although there were no significant differences in detection of larger tumours (major diameter ≥11 mm; 0.40% vs 0.28%; p=0.13). The tumour location and H. pylori status were similar in the low-detection group, high-detection group and for the highest detector.

CONCLUSION

Significant variation in the detection of hard-to-find, smaller GCs may reflect individual performance of the examination.

Recent advances in endoscopic management of gastric neoplasms

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

Quality indicators in the endoscopic detection of gastric cancer

Gastroscopy is the reference standard for the diagnosis of gastric cancer, but it is operator-dependent and associated with missed gastric cancer. The proliferation of gastroscopic examinations, increasingly for the screening and detection of subtle premalignant lesions, has motivated scrutiny of quality in gastroscopy. The concept of a high-quality endoscopic examination for the detection of superficial gastric neoplasia has been defined by expert guidelines to improve mucosal visualization, engender a systematic examination process and detect superficial neoplasia. This review discusses the evidence supporting the components of a high-quality diagnostic gastroscopic examination in relation to the detection of gastric cancer, and their potential role as procedural quality indicators to drive a structured improvement in clinically meaningful outcomes.

Visibility of early gastric cancers by texture and color enhancement imaging using a high-definition ultrathin transnasal endoscope

We evaluated whether texture and color enhancement imaging (TXI) using a high-definition ultrathin transnasal endoscope (UTE) improves the visibility of early gastric cancer (EGC) compared with white-light imaging (WLI). This study included 31 EGCs observed by TXI mode 2 using a high-definition UTE prior to endoscopic submucosal dissection. The first outcome was to compare the color differences based on Commission Internationale de l'Eclairage L*a*b* color space between EGCs and the surrounding mucosa by WLI and TXI using the UTE (objective appearance of EGC). The second outcome was to assess the visibility of EGCs by WLI and TXI using the UTE in an image evaluation test performed on 10 endoscopists (subjective appearance of EGC). Color differences between EGCs and non-neoplastic mucosa were significantly higher in TXI than in WLI in all EGCs (TXI: 16.0 ± 10.1 vs. WLI: 10.2 ± 5.5 [mean ± standard deviation], P < 0.001). Median visibility scores evaluated by 10 endoscopists using TXI were significantly higher than those evaluated using WLI (TXI: 4 [interquartile range, 4-4] vs. WLI: 4 [interquartile range, 3-4], P < 0.001). TXI using high-definition UTE improved both objective and subjective visibility of EGCs compared with WLI.

Artificial intelligence and upper gastrointestinal endoscopy: what is the optimal study design?

Upper gastrointestinal cancers (i.e., esophageal and gastric cancers) are common cancers worldwide with high mortality and morbidity. Although there is no randomized controlled trial-based evidence, early detection with endoscopy is expected to positively affect prognosis and morbidity. However, endoscopic procedures are always accompanied by human-induced errors such as overlooking of neoplasia and cancers. Recently, the use of artificial intelligence (AI) during upper gastrointestinal endoscopy is catching attention because it is expected to reduce human-induced variability of the examination. This review article introduces the overview of the expectation and current status of the AI tools for upper gastrointestinal endoscopy and shares possible challenges and corresponding solutions with readers.

A root cause analysis system to establish the most plausible explanation for post-endoscopy upper gastrointestinal cancer

BACKGROUND : Missing upper gastrointestinal cancer (UGIC) at endoscopy may prevent curative treatment. We have developed a root cause analysis system for potentially missed UGICs at endoscopy (post-endoscopy UGIC [PEUGIC]) to establish the most plausible explanations. METHODS : The electronic records of patients with UGIC at two National Health Service providers were examined. PEUGICs were defined as UGICs diagnosed 6-36 months after an endoscopy that did not diagnose cancer. An algorithm based on the World Endoscopy Organization post-colonoscopy colorectal cancer algorithm was developed to categorize and identify potentially avoidable PEUGICs. RESULTS : Of 1327 UGICs studied, 89 (6.7 %) were PEUGICs (patient median [IQR] age at endoscopy 73.5 (63.5-81.0); 60.7 % men). Of the PEUGICs, 40 % were diagnosed in patients with Barrett's esophagus. PEUGICs were categorized as: A - lesion detected, adequate assessment and decision-making, but PEUGIC occurred (16.9 %); B - lesion detected, inadequate assessment or decision-making (34.8 %); C - possible missed lesion, endoscopy and decision-making adequate (8.9 %); D - possible missed lesion, endoscopy or decision-making inadequate (33.7 %); E - deviated from management pathway but appropriate (5.6 %); F - deviated inappropriately from management pathway (3.4 %). The majority of PEUGICs (71 %) were potentially avoidable and in 45 % the cancer outcome could have been different if it had been diagnosed on the initial endoscopy. There was a negative correlation between endoscopists' mean annual number of endoscopies and the technically attributable PEUGIC rate (correlation coefficient -0.57; P = 0.004). CONCLUSION : Missed opportunities to avoid PEUGIC were identified in 71 % of cases. Root cause analysis can standardize future investigation of PEUGIC and guide quality improvement efforts.

Current status and future perspective of linked color imaging for gastric cancer screening: a literature review

Screening endoscopy has advanced to facilitate improvements in the detection and prognosis of gastric cancer. However, most early gastric cancers (EGCs) have subtle morphological or color features that are difficult to detect by white-light imaging (WLI); thus, even well-trained endoscopists can miss EGC when using this conventional endoscopic approach. This review summarizes the current and future status of linked color imaging (LCI), a new image-enhancing endoscopy (IEE) method, for gastric screening. LCI has been shown to produce bright images even at a distant view and provide excellent visibility of gastric cancer due to high color contrast relative to the surrounding tissue. LCI delineates EGC as orange-red and intestinal metaplasia as purple, regardless of a history of Helicobacter pylori (Hp) eradication, and contributes to the detection of superficial EGC. Moreover, LCI assists in the determination of Hp infection status, which is closely related to the risk of developing gastric cancer. Transnasal endoscopy (ultra-thin) using LCI is also useful for identifying gastric neoplastic lesions. Recently, several prospective studies have demonstrated that LCI has a higher detection ratio for gastric cancer than WLI. We believe that LCI should be used in routine upper gastrointestinal endoscopies.

A system based on deep convolutional neural network improves the detection of early gastric cancer

Background

Early gastric cancer (EGC) has a high survival rate, but it is difficult to diagnosis. Recently, artificial intelligence (AI) based on deep convolutional neural network (DCNN) has made significant progress in the field of gastroenterology. The purpose of this study was to establish a DCNN assist system to improve the detection of EGC.

Methods

3400 EGC and 8600 benign images were collected to train the DCNN to detect EGC. Subsequently, its diagnostic ability was compared to that of endoscopists using an independent internal test set (ITS, including 1289 images) and an external test set (ETS, including 542 images) come from three digestive center.

Results

The diagnostic time of DCNN and endoscopists were 0.028s, 8.05 ± 0.21s, 7.69 ± 0.25s in ITS, and 0.028s, 7.98 ± 0.19s, 7.50 ± 0.23s in ETS, respectively. In ITS, the diagnostic sensitivity and accuracy of DCNN are 88.08%(95% confidence interval,95%CI,85.24%-90.44%), 88.60% (95%CI,86.74%-90.22%), respectively. In ETS, the diagnostic sensitivity and accuracy are 92.08% (95%CI, 87.91%- 94.94%),92.07%(95%CI, 89.46%-94.08%),respectively. DCNN outperformed all endoscopists in ETS, and had a significantly higher sensitivity than the junior endoscopists(JE)(by18.54% (95%CI, 15.64%-21.84%) in ITS, also higher than JE (by21.67%,95%CI, 16.90%-27.32%) and senior endoscopists (SE) (by2.08%, 95%CI, 0.75%-4.92%)in ETS. The accuracy of DCNN model was higher (by10.47%,95%CI, 8.91%-12.27%) than that of JE in ITS, and also higher (by14.58%,95%CI, 11.84%-17.81%; by 1.94%,95%CI,1.25%-2.96%, respectively) than JE and SE in ETS.

Conclusion

The DCNN can detected more EGC images in a shorter time than the endoscopists. It will become an effective tool to assist in the detection of EGC in the near future.

Quality performance measures in upper gastrointestinal endoscopy for lesion detection: Italian AIGO-SIED-SIGE joint position statement

Esophagogastroduodenoscopy (EGD) plays a crucial role in the management of gastroduodenal diseases by allowing a direct and accurate evaluation of the mucosa and the execution of several operative maneuvers. Despite a constant development of new imaging tools and operative devices, the widespread use of EGD has not resulted in a significant reduction of mortality for patients affected by esophageal/gastric cancer during the last three decades in Western countries. Evidence indicates that this disheartening scenario derives from a high variability of execution of EGD which determines its quality and diagnostic yield, delaying the diagnosis of neoplastic diseases. Based on this evidence, in recent years many scientific societies have produced different position papers aimed at defining quality performance measures in EGD. Thus, the Italian Association of Gastroenterologists and Endoscopists, the Italian Society of Digestive Endoscopy and the Italian Society of Gastroenterology have produced this joint document based on the review of ASGE, ACG, BSG, ESGE and Asian Consensus EGD position papers with the aim of indicating the quality standards of EGD (pre-, intra- and post-procedure) focused on lesion detection to be adopted in the Italian context.

Linked color imaging improves identification of early gastric cancer lesions by expert and non-expert endoscopists

BACKGROUND AND AIMS

Early gastric cancer (EGC) lesions are often subtle and endoscopically poorly visible. The aim of this study is to evaluate the additive effect of linked color imaging (LCI) next to white-light endoscopy (WLE) for identification of EGC, when assessed by expert and non-expert endoscopists.

METHODS

Forty EGC cases were visualized in corresponding WLE and LCI images. Endoscopists evaluated the cases in 3 assessment phases: Phase 1: WLE images only; Phase 2: LCI images only; Phase 3: WLE and LCI images side-to-side. First, 3 expert endoscopists delineated all cases. A high level of agreement between the expert delineations corresponded with a high AND/OR ratio. Subsequently, 62 non-experts indicated their preferred biopsy location. Outcomes of the study are as follows: (1) difference in expert AND/OR ratio; (2) accuracy of biopsy placement by non-expert endoscopists; and (3) preference of imaging modality by non-expert endoscopists.

RESULTS

Quantitative agreement between experts increased significantly when LCI was available (0.58 vs. 0.46, p = 0.007). This increase was more apparent for the more challenging cases (0.21 vs. 0.47, p < 0.001). Non-experts placed the biopsy mark more accurately with LCI (82.3% vs. 87.2%, p < 0.001). Again this increase was more profound for the more challenging cases (70.4% vs. 83.4%, p < 0.001). Non-experts indicated to prefer LCI over WLE.

CONCLUSION

The addition of LCI next to WLE improves visualization of EGC. Experts reach higher consensus on discrimination between neoplasia and inflammation when using LCI. Non-experts improve their targeted biopsy placement with the use of LCI. LCI therefore appears to be a useful tool for identification of EGC.

Usefulness of linked color imaging for the detection of obscure early gastric cancer: Multivariate analysis of 508 lesions

OBJECTIVES

Early gastric cancers (EGCs) of the elevated type or with submucosal invasion are easily found by routine endoscopy. However, most early cancers are challenging to detect because of subtle morphological or color differences from surrounding atrophic mucosa and intestinal metaplasia. Linked color imaging (LCI) enhances mucosal color difference, making it easier to detect EGCs. The aim of this study is to clarify the advantages and possible disadvantages of LCI for screening for obscure EGC.

METHODS

A total of 665 malignant gastric lesions resected using endoscopic submucosal dissection between January 2015 and April 2018 were retrospectively reviewed. Obviously detectable lesions were not included in the main analysis when determining the target lesion. White light imaging (WLI)/LCI images of 508 endoscopically obscure malignant lesions were included in the final analysis and evaluated by three non-expert and three expert endoscopists using visibility scores for detection and extent.

RESULTS

The detection visibility scores using LCI were significantly higher than those using WLI regardless of lesion characteristics including location, size, histological type, depth of invasion, and Helicobacter pylori status. The detection score improved in 46.4% cases and deteriorated in 4.9% when the modality changed from WLI to LCI. A mixed-effects multivariate logistic regression analysis showed that use of LCI (odds ratio [OR] 2.57), elevated type (OR 1.92), invasion to submucosa (OR 2.18) were significantly associated with improved visibility of EGC.

CONCLUSIONS

Linked color imaging significantly improves visibility of EGC regardless of differences in lesion morphology, histology, location, depth of invasion, and H. pylori status compared to conventional WLI.

Prevalence and risk factors of upper gastrointestinal cancers missed during endoscopy: a nationwide registry-based study

BACKGROUND

A significant proportion of upper gastrointestinal cancers (UGICs) remain undetected during esophagogastroduodenoscopy (EGD). We investigated the characteristics and risk factors of UGICs missed during endoscopy.

METHODS

In this nationwide registry-based study, we analyzed two large Polish datasets (National Health Fund and National Cancer Registry) to identify individuals who underwent EGD and were subsequently diagnosed with UGIC. Cancers diagnosed < 6 months after EGD were defined as "prevalent" and those within ≥ 6- < 36 months as "missed." We compared the characteristics of missed and prevalent cancers, and analyzed the risk factors for missed UGICs in a multivariable regression model.

RESULTS

We included 4 105 399 patients (mean age 56.0 years [SD 17.4]; 57.5 % female) who underwent 5 877 674 EGDs in 2012-2018. Within this cohort, 33 241 UGICs were diagnosed, of which 1993 (6.0 %) were missed. Within esophageal neoplasms, adenocarcinomas were more frequently missed than squamous cell cancers (6.1 % vs. 4.2 %), with a relative risk of 1.4 (95 % confidence interval [CI] 1.1-1.8, P = 0.01). Most gastric cancers were adenocarcinomas, of which 5.7 % were classified as missed. Overall, a higher proportion of missed UGICs than prevalent cancers presented at an advanced stage (42.2 % vs. 36.2 %, P < 0.001). Risk factors for missed UGICs included initial EGD performed within primary (vs. secondary) care (odds ratio [OR] 1.3, 95 %CI 1.2-1.5), female sex (OR 1.3, 95 %CI 1.2-1.4), and higher comorbidity (Charlson comorbidity index ≥ 5 vs. 0; OR 6.0, 95 %CI 4.7-7.5).

CONCLUSIONS

Among UGICs, esophageal adenocarcinomas were missed most frequently. Missed cancers occur more frequently within the primary care sector and are found more often in women and individuals with multiple comorbidities.

Interval gastric cancer: A call to attentiveness and action

INTRODUCTION AND AIMS

Endoscopy is the most effective method for identifying gastric adenocarcinoma (GAC). Interval gastric cancer (IGC) is GAC that is diagnosed 2-3 years after a normal endoscopy. Its characteristics are unknown in the Colombian environment. The clinical, histopathologic, and endoscopic characteristics were evaluated, along with the presentation rate, proton pump inhibitor (PPI) use, and IGC survival rate, and compared with other types of GAC.

METHODS

A retrospective, analytic study was conducted on a prospective cohort. It evaluated 513 patients with GAC treated at our institution, within the time frame of January 2012 and June 2018. The patients had endoscopic diagnosis of GAC and endoscopy within the past three years that was negative for tumor.

RESULTS

A total of 513 patients diagnosed with GAC were evaluated. Forty-two of the patients had IGC (8.2%): 9 early lesions and 33 advanced lesions (79%). The IGCs were smaller (31 vs. 41 mm; P < .01), as well as flatter and more depressed (P < .01). There was no association with PPI use, but there was an association with a history of gastrectomy and anastomosis (P = .02), as well as the absence of red flags (P < .003). The most frequent locations were the gastric body (52%) and the antrum (26%). Overall two-year survival was similar between IGC and GAC (37.1 vs. 39.3%, P = .72).

CONCLUSION

A total of 8.2% of recently diagnosed GAC were cases of IGC. The presence of anastomosis and the absence of red flags were related to IGC. Overall survival was poor and there were no differences from the other types of GAC detected.

Emerging texture and color enhancement imaging in early gastric cancer

Screening endoscopy improves detection and prognosis of patients with gastric cancer. However, even expert endoscopists can miss early gastric cancer under standard white light imaging. Texture and color enhancement imaging (TXI) is an image-enhanced endoscopy that enhances brightness, surface irregularities such elevation or depression, and subtle color changes. A few image-oriented studies have compared the gastric color differences between neoplastic and peripheral areas under both white light imaging and TXI. The results not only suggested that the overall color differences to be more pronounced in TXI, but also that TXI mode 1 was superior to white light imaging in the visibility of early gastric cancer. Despite the promising results in these initial studies, it is unclear whether the superiority of the image-enhanced endoscopy will translate into an improvement in early gastric cancer detection in real practice. Therefore, large-scale prospective studies are necessary to investigate the efficacy of this new technology in the evaluation of patients undergoing screening endoscopy.

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.

Clinical and Endoscopic Characteristics Associated With Post-Endoscopy Upper Gastrointestinal Cancers: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Ten percent of patients with an upper gastrointestinal cancer will have received an esophagogastroduodenoscopy (EGD) within 3 years before diagnosis, termed post-endoscopy upper gastrointestinal cancers (PEUGIC). We aimed to determine the characteristics of PEUGIC, and compare these with detected cancers.

METHODS

We searched MEDLINE and Embase from inception for studies comparing the characteristics of PEUGIC and detected upper gastrointestinal cancers, and reported findings at the initial "cancer-negative" endoscopy. We synthesized results using random effects meta-analysis. This review is registered on PROSPERO, CRD42019125780.

RESULTS

A total of 2696 citations were screened and 25 studies were included, comprising 81,184 UGI cancers, of which 7926 were considered PEUGIC. For PEUGIC assessed within 6 to 36 months of a "cancer-negative" EGD, the mean interval was approximately 17 months. Patients with PEUGIC were less likely to present with dysphagia (odds ratio [OR] 0.37) and weight loss (OR 0.58) and were more likely to present with gastroesophageal reflux (OR 2.64) than detected cancers. PEUGICs were more common in women in Western populations (OR 1.30). PEUGICs were typically smaller at diagnosis and associated with less advanced disease staging compared with detected cancers (OR 2.87 for stage 1 vs 2-4). Most EGDs (>75%) were abnormal preceding diagnosis of PEUGIC.

CONCLUSIONS

There is a substantial delay in the diagnosis of PEUGIC. They are less likely to present with alarm symptoms than detected cancers. PEUGICs are overall less advanced at diagnosis. Most patients with PEUGIC have abnormalities reported at the preceding "cancer-negative" EGD. The epidemiology of PEUGIC may inform preventive strategy.

Endoscopic characteristics in predicting prognosis of biopsy-diagnosed gastric low-grade intraepithelial neoplasia

BACKGROUND

Endoscopic biopsy can underestimate gastric malignancies as low-grade intraepithelial neoplasia (LGIN). Definitively diagnosed LGIN would progress. This study aimed to evaluate predictive factors to identify malignancies misdiagnosed as LGIN by biopsy and LGIN at high risk of progression.

METHODS

The clinical records of patients diagnosed with gastric LGIN by endoscopic biopsy who underwent at least two endoscopies during the first year of follow-up between 2007 and 2017 were retrospectively collected. Three endoscopists reviewed photographs of the initial endoscopy, described lesion characteristics, and made endoscopic diagnoses. Logistic regression was used to analyze predictors to identify malignancies underestimated as LGIN. A receiver operating characteristic curve was used to evaluate the diagnostic accuracy of these predictors. Patient clinical outcomes of follow-up >1 year were collected. Kaplan-Meier estimates with log-rank tests and Cox proportional hazards regression were used to analyze predictors of progression.

RESULTS

Overall, 48 of 182 (26.4%) patients were proven to have malignancies. A single lesion, a large lesion size, and marked intestinal metaplasia (IM) were independent predictors of initially misdiagnosed malignancies. The area under the curve of these predictors was 0.871, with a sensitivity of 68.7% and specificity of 92.5%. Twelve of 98 patients (12.2%) progressed during the 33-month median follow-up period. A whitish appearance, irregular margins, marked IM, and histological diagnosis of LGIN more than twice within the first year were predictors for progression.

CONCLUSIONS

Lesions diagnosed as LGIN by biopsy with marked IM and other predictors above should be prudently treated for high potential to be malignancies or progress. Endoscopic follow-up with repeated biopsies within the first year is recommended.

Gastric Cancers Missed at Upper Endoscopy in Central Norway 2007 to 2016-A Population-Based Study

Simple Summary

Stomach cancer may be missed during upper endoscopy. We have examined how often this occurs and identified factors associated with missed cancers. Among 730 patients with gastric cancer, 67 (9.2%) were missed during endoscopy 6 to 36 months prior to the cancer diagnosis. Missed cancers were more often located in the upper part of the stomach, of Lauren’s diffuse histologic type and more frequent in patients with previous Billroth II operation. The missed cancers were diagnosed at somewhat earlier stages than the non-missed cancers. In missed cancers, an ulceration was more often found in patients with shorter time interval between the first endoscopy and the endoscopy where the cancer was diagnosed. The factors associated with missed stomach cancers should be kept in mind by doctors performing endoscopies as this may lead to an earlier diagnosis of cancer.

Abstract

Background: The rates of missed gastric cancers (MGC) at upper endoscopy (UE) has been reported at 5–10% in Western countries. We aimed to calculate the rate of MGC and identify factors associated with MGC. Methods: Retrospective population-based cohort study including 730 patients diagnosed with gastric adenocarcinoma in Central Norway 2007–2016. MGCs were incident gastric adenocarcinomas diagnosed 6–36 months after a previous UE. Factors associated with MGC were examined. Definitely missed (UE 6–12 months prior) and potentially missed (UE 12–36 months prior) MGCs were compared. Results: Sixty-seven (9.2%) of 730 gastric cancers were MGC. MGC were associated with localization (p = 0.009) and more frequent in the corpus, Lauren’s histological type (p = 0.028) and diffuse type more prevalent, and previous Billroth 2-operation (14.9% vs. 4.7%, p = 0.001). MGCs were diagnosed at earlier stages (p = 0.037). An ulceration was more common in patients with definitely missed than potentially MGC (40.9% vs. 17.8%, p = 0.041). Conclusions: MGC accounted for 9.2% of gastric cancers in Central Norway. MGC were associated with localization in the corpus, Lauren´s diffuse type and previous Billroth-2-operation. Intensified follow-up and adequate biopsy sampling of patients with gastric ulcerations could reduce the rate of missed gastric cancers.

Visibility of early gastric cancer in texture and color enhancement imaging

Objective

There are little data regarding the efficacy of texture and color enhancement imaging (TXI) for early gastric cancer (EGC) diagnosis. This study aimed to compare the color difference and visibility of EGC between white light imaging (WLI) and TXI.

Methods

This study included 20 EGCs of 18 patients undergoing endoscopic submucosal dissection. Still images of EGC in WLI, TXI mode 1 (with color enhancement), and TXI mode 2 (without color enhancement), which were consistent in distance, angle, and air insufflation, were constructed by computer simulation. The center of the lesion, eight equal peripheral points 5 mm outside the lesion, and eight inner points two‐thirds of the distance from peripheral points to the EGC lesion center were annotated. Mean color differences (ΔE) of the area between peripheral and inner points per lesion in WLI, TXI mode 1, and TXI mode 2 were analyzed. In addition, four endoscopists independently scored the visibility of EGC images of TXI mode 1 and 2 compared with WLI.

Results

Clinicopathological characteristics were as follows: 0‐IIa/0‐IIb/0‐IIc/0‐IIa+IIc = 6/1/11/2, reddish/pale = 10/10, differentiated/undifferentiated = 18/2, median tumor size = 13.5 mm. Mean ΔE ± SD = WLI/TXI mode1/TXI mode2 = 10.3 ± 4.7, 15.5 ± 7.8, and 12.7 ± 6.1, respectively. Mean ΔE was significantly higher in TXI mode 1 than in WLI. Visibility (improved/no change/decreased) was 7/13/0 and 4/16/0 in TXI mode 1 and 2, respectively. The visibility was significantly more commonly improved in the macroscopic type 0‐IIc or 0‐IIb than in 0‐IIa or IIa+IIc in TXI mode 1.

Conclusions

TXI could improve the visibility of EGC compared with WLI.

Application of convolutional neural network in detecting and classifying gastric cancer

Gastric cancer (GC) is the fifth most common cancer in the world, and at present, esophagogastroduodenoscopy is recognized as an acceptable method for the screening and monitoring of GC. Convolutional neural networks (CNNs) are a type of deep learning model and have been widely used for image analysis. This paper reviews the application and prospects of CNNs in detecting and classifying GC, aiming to introduce a computer-aided diagnosis system and to provide evidence for subsequent studies.

Prevalence and characteristics of post-gastroscopy gastric cancer: A retrospective study from an academic medical center

BACKGROUND AND STUDY AIMS

Gastric cancer is diagnosed by endoscopy but false negative rates of up to 10% in the west and 40% in Asia have been reported. In Lebanon, little is known about the rates of post-gastroscopy gastric cancer (PGGC), defined as the proportion of patients diagnosed with gastric cancer with a negative previous examination within 2 years of diagnosis. We aimed to examine the rate of PGGC and its risk factors, clinico-pathologic and endoscopic characteristics at a University medical Center.

PATIENTS AND METHODS

Retrospective analysis of patients with histologically proven gastric malignancy over the last 14 years. Patients with history of upper endoscopy preceding the index diagnostic endoscopy by 6 to 24 months were included.

RESULTS

18,976 patients underwent upper endoscopy and gastric cancer was diagnosed in 323 (1.7%). Of those, only 4 (1.2%) had a preceding endoscopy within 6 to 24 months of diagnosis: 3 adenocarcinoma and one MALT lymphoma. Upon review of the initial endoscopy, a mucosal abnormality had been noted in all 4 patients and biopsies taken in 3 were negative for cancer. The mean time to cancer diagnosis was 8 months (range 6-13 months).

CONCLUSION

A small proportion of gastric carcinomas are missed on endoscopy in this study. Patients with endoscopic evidence of mucosal abnormalities and negative biopsies should undergo repeat examination with multiple biopsies. Proper endoscopic technique, lesion recognition and adoption of performance improvement measures are important to optimize endoscopic practice.

Characteristics of interval gastric neoplasms detected within two years after negative screening endoscopy among Koreans

Background

In Korea, where gastric cancer is highly prevalent, biennial endoscopy is recommended among individuals over 40. Even under regular screening, some are still diagnosed at advanced stages. We aimed to identify characteristics of interval gastric neoplasms (IGNs) with rapid progression.

Results

Newly-diagnosed gastric neoplasms detected in screening endoscopy between January 2004 and May 2016 were reviewed. Among them, those who had previous endoscopy within 2 years were enrolled. Endoscopic findings, family history of gastric cancer, smoking, and H. pylori status were analysed. Totally, 297 IGN cases were enrolled. Among them, 246 were endoscopically treatable IGN (ET-IGN) and 51 were endoscopically untreatable IGNs (EUT-IGN) by the expanded criteria for endoscopic submucosal dissection. Among EUT-IGNs, 78% were undifferentiated cancers (40/51) and 33% showed submucosal invasion (13/40). They were median 2.0 cm in size and more commonly located in the proximal stomach than ET-IGNs (70.6% vs. 41.9%, p < 0.001). EUT-IGN was independently related with age < 60 (OR, 2.09; 95%CI, 1.03–4.26, p = 0.042), H. pylori (OR, 2.81; 95%CI, 1.20–6.63, p = 0.018), and absent/mild gastric atrophy (OR, 2.67; 95%CI, 1.25–5.72, p = 0.011). Overall and disease-specific survival were not significantly different between the two groups, however EUT-IGN tended to have short disease-specific survival (overall survival, p = 0.143; disease-specific survival, p = 0.083).

Conclusions

Uniform screening endoscopy with two-year interval seems not enough for rapid-growing gastric neoplasms, such as undifferentiated cancers. They tended to develop in adults younger than 60 with H. pylori infection without severe gastric atrophy. More meticulous screening, especially for proximal lesions is warranted for adults younger than 60 with H. pylori infection before development of gastric atrophy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07929-y.

Quality performance measures for small capsule endoscopy: Are the ESGE quality standards met?

Background and study aims  The European Society of Gastrointestinal Endoscopy (ESGE) recently issued a quality performance measures document for small bowel capsule endoscopy (SBCE). The aim of this nationwide survey was to explore SBCE practice with ESGE quality measures as a benchmark. Patients and methods  A dedicated per-center semi-quantitative questionnaire based on ESGE performance measures for SBCE was created by a group of SBCE experts. One-hundred-eighty-one centers were invited to participate and were asked to calculate performance measures for SBCE performed in 2018. Data were compared with 10 ESGE quality standards for both key and minor performance measures. Results  Ninety-one centers (50.3 %) participated in the data collection. Overall in the last 5 years (2014-2018), 26,615 SBCEs were performed, 5917 of which were done in 2018. Eighty percent or more of the participating centers reached the minimum standard established by the ESGE Small Bowel Working Group (ESBWG) for four performance measures (indications for SBCE, complete small bowel evaluation, diagnostic yield and retention rate). Conversely, compliance with six minimum standards established by ESBWG concerning adequate bowel preparation, patient selection, timing of SBCE in overt bleeding, appropriate reporting, reading protocols and referral to device-assisted enteroscopy was met by only 15.5 %, 10.9 %, 31.1 %, 67.7 %, 53.4 %, and 32.2 % of centers, respectively. Conclusions  The present survey shows significant variability across SBCE centers; only four (4/10: 40 %) SBCE procedural minimum standards were met by a relevant proportion of the centers ( ≥ 80 %). Our data should help in identifying target areas for quality improvement programs in SBCE.

Detecting early gastric cancer: Comparison between the diagnostic ability of convolutional neural networks and endoscopists

OBJECTIVES

Detecting early gastric cancer is difficult, and it may even be overlooked by experienced endoscopists. Recently, artificial intelligence based on deep learning through convolutional neural networks (CNNs) has enabled significant advancements in the field of gastroenterology. However, it remains unclear whether a CNN can outperform endoscopists. In this study, we evaluated whether the performance of a CNN in detecting early gastric cancer is better than that of endoscopists.

METHODS

The CNN was constructed using 13,584 endoscopic images from 2639 lesions of gastric cancer. Subsequently, its diagnostic ability was compared to that of 67 endoscopists using an independent test dataset (2940 images from 140 cases).

RESULTS

The average diagnostic time for analyzing 2940 test endoscopic images by the CNN and endoscopists were 45.5 ± 1.8 s and 173.0 ± 66.0 min, respectively. The sensitivity, specificity, and positive and negative predictive values for the CNN were 58.4%, 87.3%, 26.0%, and 96.5%, respectively. These values for the 67 endoscopists were 31.9%, 97.2%, 46.2%, and 94.9%, respectively. The CNN had a significantly higher sensitivity than the endoscopists (by 26.5%; 95% confidence interval, 14.9-32.5%).

CONCLUSION

The CNN detected more early gastric cancer cases in a shorter time than the endoscopists. The CNN needs further training to achieve higher diagnostic accuracy. However, a diagnostic support tool for gastric cancer using a CNN will be realized in the near future.

A novel combination of serum microRNAs for the detection of early gastric cancer

BACKGROUND

The aim of this study was to identify serum miRNAs that discriminate early gastric cancer (EGC) samples from non-cancer controls using a large cohort.

METHODS

This retrospective case-control study included 1417 serum samples from patients with EGC (seen at the National Cancer Center Hospital in Tokyo between 2008 and 2012) and 1417 age- and gender-matched non-cancer controls. The samples were randomly assigned to discovery and validation sets and the miRNA expression profiles of whole serum samples were comprehensively evaluated using a highly sensitive DNA chip (3D-Gene^®) designed to detect 2565 miRNA sequences. Diagnostic models were constructed using the levels of several miRNAs in the discovery set, and the diagnostic performance of the model was evaluated in the validation set.

RESULTS

The discovery set consisted of 708 samples from EGC patients and 709 samples from non-cancer controls, and the validation set consisted of 709 samples from EGC patients and 708 samples from non-cancer controls. The diagnostic EGC index was constructed using four miRNAs (miR-4257, miR-6785-5p, miR-187-5p, and miR-5739). In the discovery set, a receiver operating characteristic curve analysis of the EGC index revealed that the area under the curve (AUC) was 0.996 with a sensitivity of 0.983 and a specificity of 0.977. In the validation set, the AUC for the EGC index was 0.998 with a sensitivity of 0.996 and a specificity of 0.953.

CONCLUSIONS

A novel combination of four serum miRNAs could be a useful non-invasive diagnostic biomarker to detect EGC with high accuracy. A multicenter prospective study is ongoing to confirm the present observations.

The modern management of Barrett's oesophagus and related neoplasia: role of pathology

Modern management of Barrett's oesophagus and related neoplasia essentially focuses upon surveillance to detect early low-risk neoplastic lesions and offering organ-preserving advanced endoscopic therapies, while traditional surgical treatments of oesophagectomy and lymph node clearance with or without chemoradiation are preserved only for high-risk and advanced carcinomas. With this evolution towards figless invasive therapy, the choice of therapy hinges upon the pathological assessment for risk stratifying patients into those with low risk for nodal metastasis who can continue with less invasive endoscopic therapies and others with high risk for nodal metastasis for which surgery or other forms of treatment are indicated. Detection and confirmation of neoplasia in the first instance depends upon endoscopic and pathological assessment. Endoscopic examination and biopsy sampling should be performed according to the recommended protocols, and endoscopic biopsy interpretation should be performed applying standard criteria using appropriate ancillary studies by histopathologists experienced in the pathology of Barrett's disease. Endoscopic resections (ERs) are both diagnostic and curative and should be performed by clinicians who are skilled with advanced endoscopic techniques. Proper preparation and handling of ERs are essential to assess histological parameters that dictate the curative nature of the procedure. Those parameters are adequacy of resection and risk of lymph node metastasis. The risk of lymph node metastasis is determined by depth invasion and presence of poor differentiation and lymphovascular invasion. Those adenocarcinomas with invasion up to muscularis mucosae (pT1a) and those with superficial submucosal invasion (pT1b) up to 500 µ with no poor differentiation and lymphovascular invasion and negative margins may be considered cured by endoscopic resections.

Survival outcomes and rate of missed upper gastrointestinal cancers at routine endoscopy: a single centre retrospective cohort study

OBJECTIVES

Data on the long-term survival outcome of patients with missed upper gastrointestinal cancers (MUGC) is lacking. Retrospective studies have found no difference in 1- and 2-year survival among patients with missed gastric and oesophageal cancers; we thus aimed to assess 3-year survival of patients with MUGC at oesophagogastroduodenoscopy.

METHODS

This was a retrospective cohort study conducted at a single tertiary endoscopy centre. All oesophagogastroduodenoscopies performed between January 2007 and December 2015 were included in the study. The endoscopy database was cross-matched with the Slovenian Cancer Registry database. Missed cancers were defined as those diagnosed within 36 months after a negative oesophagogastroduodenoscopy.

RESULTS

During the study period, 29 617 oesophagogastroduodenoscopies were performed. In total, 422 upper gastrointestinal cancers were diagnosed and the rate of missed gastric cancers was 7.3% (95% CI, 4.9-10.6%) (26/354), and 4.4% (95% CI, 0.9-12.4%) for oesophageal cancers (3/68). Three-year survival of patients with MUGC was shorter than that of those with non-MUGC, being 12% (95% CI, 1-25%) vs. 31% (95% CI, 26-36%) (P = 0.043) for gastric and 0 vs. 9% (95% CI, 1-17%) (P = 0.121) for oesophageal cancer.

CONCLUSION

Missed gastric cancer during oesophagogastroduodenoscopy may be associated with shorter 3-year survival compared to patients whose gastric cancer was diagnosed at index oesophagogastroduodenoscopy.

Quality indicators in diagnostic upper gastrointestinal endoscopy

Upper gastrointestinal (UGI) endoscopy contributes a major clinical service with consistently growing demand around the world. Its utility corresponds to varying epidemiological issues throughout the globe, with cancer screening and surveillance being of the utmost priority. Despite high accuracy in neoplasia detection, UGI endoscopy remains a highly operator-dependent procedure, characterized by a substantial rate of missed pathology. Despite an overall lack of high-quality performance measures, there is an increased level of awareness about the need for quality control of this procedure, which is reflected in several guidelines and position statements published in recent years. It is widely recognized that quality assessment should go beyond mere technical aspects of the examination, and include both pre- and post-procedural factors. By this means, quality control encompasses the entire patient experience with the health care provider, from appropriate indication and physical assessment, through high-quality endoscopy service, to appropriate follow up and patient satisfaction. This article aims to review the available and emerging quality metrics for UGI endoscopy, taken mostly from Western endoscopy societies, with references to Asian recommendations where appropriate. The paper is limited solely to diagnostic UGI endoscopy and does not include performance measures for therapeutic procedures.

Effect of pre-endoscopy intake of simethicone solution on endoscopic mucosal visibility: A single blinded, placebo control, randomized trial

Objective:

To determine effect of pre-endoscopy intake of simethicone solution on endoscopic mucosal visibility.

Methodology:

A randomized, single blinded placebo control trial was done in patients undergoing oesophago-gastro-duodenoscopy for any indication at DOTs Endoscopy Suite, CHK during the period of April to June 2019. Informed consent was taken. Patients were randomly allocated in two groups. Group-A received placebo while Group-B received Simethicone. Evaluation of mucosal visibility was assessed at 4 sites (oesophagus, fundus, antrum & duodenum) by previously validated scoring. Mean of visibility scores were compared in two groups.

Results:

Two hundred and forty-eight patients were inducted and randomly allocate to two groups of 124 each. Mean of total sum of scores in Group-A was 8.14 ±2.44 and that of Group-B was 5.80 ±1.75 (p<0.001). Adequate visibility in Group-A was seen in 41.1% and that in Group-B was 78.2% (p<0.001).

Conclusion:

Use of Simethicone significantly improves mucosal visibility during OGD.

A prospective randomized controlled trial comparing simethicone, N-acetylcysteine, sodium bicarbonate and peppermint for visualization in upper gastrointestinal endoscopy

OBJECTIVES

Early cancer detection is crucial in improving the patients' quality of life and upper gastrointestinal endoscopy (EGD) plays a key role in this detection. Many clearing mechanisms may be applied to create good endoscopic visualizations for the upper gastrointestinal tract using mucolytic agents, antifoaming agents, proteolytic enzymes and neutralizers. The aim of this study is to compare the effects of simethicone, N-acetylcysteine (NAC), sodium bicarbonate and peppermint as pre-medications for visualization of esophagogastroduodenoscopy (EGD).

METHODS

This study was a single center prospective randomized controlled trial. The patients were randomly allocated to one of four treatment groups. Group A: water; Group B: water with simethicone; Group C: water with simethicone plus NAC 600 mg; Group D: water with simethicone, NAC, sodium bicarbonate and peppermint.

RESULTS

A total of 128 patients were enrolled and evaluated in this study. Total visibility score (TVS) of Groups A, B, C, and D were 13.4 ± 1.86, 10.5 ± 1.45, 7.15 ± 0.98 and 6.4 ± 1.43, respectively. Group D showed lower TVS than other groups. The procedural durations of Groups C and D were significantly shorter than Group A. The volume of solution for mucosal cleansing of Groups C and D was significantly lower than Groups A and B.

CONCLUSIONS

The application of simethicone plus NAC is safe, improves endoscopic visualization and requires a minimal amount of mucosal cleansing solution. The addition of sodium bicarbonate and peppermint further improved visualization for the upper and lower gastric body. Thai Clinical Trials Registry (TCTR) with a reference number; TCTR20190501002.

Linked Color Imaging Highlights Flat Early Gastric Cancer

While linked color imaging (LCI) may allow flat early gastric cancer to be detected early, the endoscopic and pathological features of lesions detected by LCI remain poorly described. Screening esophagogastroduodenoscopy performed on a 68-year-old woman revealed a yellowish, flat lesion shown to be reddish in its central area, located in the anterior wall of the gastric lower body on white light imaging (WLI). On LCI, the lesion was highlighted as an orangish, flat lesion shown to be purple-colored in its central area, surrounded by lavender-colored tissue. Endoscopic submucosal dissection performed led to the patient being diagnosed with tubular adenocarcinoma, well-differentiated type (tub1), pT1a (M). This case suggests that LCI may prove more useful than WLI for the detection of flat early gastric cancer lesions.

Gastric adenocarcinoma mimicking a submucosal tumor: A case report

BACKGROUND

Submucosal tumor (SMT)-like early-stage gastric cancer (GC) has rarely been reported. It is difficult to consider the possibility of GC and differentiate it from other submucosal lesions.

CASE SUMMARY

We present the case of a 50-year-old male patient with a 1.6 cm SMT-like flat elevated lesion covered by congested mucosa on the gastric angle. Magnifying endoscopy with narrow-band imaging, endoscopic biopsy, endoscopic ultrasound, and computed tomography were performed for diagnosis. Endoscopic submucosal dissection and gastrectomy with lymph node dissection were performed. The post-resection pathological analysis led to a final diagnosis of GC (Bormann type I, T1bN2M0).

CONCLUSION

GC should be considered when detecting an SMT-like lesion in the stomach.

Gastric cancer missed at esophagogastroduodenoscopy in a well-defined Spanish population

BACKGROUND

Although esophagogastroduodenoscopy (EGD) is the standard procedure for the diagnosis of gastric cancer (GC), some GCs are missed. There are no published data on the missed rate of GC in Spain.

AIMS

To determine the frequency and characteristics of missed GCs and assess the quality of the EGD in a specific population with GC.

METHODS

Records of all patients diagnosed with gastric adenocarcinoma between 2012 and 2016 in a defined geographic area were reviewed. Missed GC was defined as a case with a prior negative EGD for cancer. Quality indicators from the prior EGDs were measured.

RESULTS

From 212 cases of GC, 25 cases were excluded. Seventeen out of 187 patients had a prior EGD (9.1%). Twelve of those 17 missed GC had a prior EGD with some abnormal findings. In 6 of them, biopsies were taken. Survival was no different between patients with missed and non-missed GC. Quality indicators that failed to meet standards were recording time, image documentation, and a protocol of biopsies.

CONCLUSIONS

Missed GC in an EGD in a defined population in Spain is not uncommon (9.1%). The endoscopist is an important factor in missed GC due to lack of adequate detection and sampling error. Compliance with performance of quality indicators could reduce missed GC.

Factors associated with oesophagogastric cancers missed by gastroscopy: a case-control study

INTRODUCTION

There is increasing demand for gastroscopy in the United Kingdom. In around 10% of patients, gastroscopy is presumed to have missed oesophagogastric (OG) cancer prior to diagnosis. We examine patient, endoscopist and service level factors that may affect rates of missed OG cancers.

METHODS

Gastroscopies presumed to have missed OG cancers performed up to 3 years prior to diagnosis were identified over 6 years in Sheffield, UK. Factors related to the patient, endoscopist and endoscopy lists were examined in a case-control study. Procedures which missed cancer were compared with two procedure controls: the procedures which subsequently diagnosed cancer in the same patient, and second, endoscopist matched procedures diagnostic of small benign focal lesions.

RESULTS

We identified 48 (7.7%) cases of missed OG cancer. Endoscopy lists on which OG cancer diagnoses were missed contained a greater number of total procedures compared with lists on which diagnoses were subsequently made (OR 1.42 95% CI 1.13 to 1.78) and when compared with lists during which matched endoscopists diagnosed benign small focal lesions (OR 1.25, 95% CI 1.02 to 1.52). The use of sedation, endoscopist profession and experience, or time of procedure were not associated with a missed cancer.

CONCLUSION

7.7% of patients diagnosed with OG cancer could have been diagnosed and treated earlier. Our study suggests that endoscopy lists with greater numbers of procedures may be associated with missed OG cancers. The use of sedation, endoscopist background or time of procedure did not increase the risk of missed cancer procedures.

Endoscopist biopsy rate as a quality indicator for outpatient gastroscopy: a multicenter cohort study with validation

BACKGROUND AND AIMS

The diagnosis of gastric premalignant conditions (GPCs) relies on endoscopy with mucosal sampling. We hypothesized that the endoscopist biopsy rate (EBR) might constitute a quality indicator for EGD, and we have analyzed its association with GPC detection and the rate of missed gastric cancers (GCs).

METHODS

We analyzed EGD databases from 2 high-volume outpatient units. EBR values, defined as the proportion of EGDs with ≥1 biopsy to all examinations were calculated for each endoscopist in Unit A (derivation cohort) and divided by the quartile values into 4 groups. Detection of GPC was calculated for each group and compared using multivariate clustered logistic regression models. Unit B database was used for validation. All patients were followed in the Cancer Registry for missed GCs diagnosed between 1 month and 3 years after EGDs with negative results.

RESULTS

Sixteen endoscopists in Unit A performed 17,490 EGDs of which 15,340 (87.7%) were analyzed. EBR quartile values were 22.4% to 36.7% (low EBR), 36.8% to 43.7% (moderate), 43.8% to 51.6% (high), and 51.7% and 65.8% (very-high); median value 43.8%. The odds ratios for the moderate, high, and very-high EBR groups of detecting GPC were 1.6 (95% confidence interval [CI], 1.3-1.9), 2.0 (95% CI, 1.7-2.4), and 2.5 (95% CI, 2.1-2.9), respectively, compared with the low EBR group (P < .001). This association was confirmed with the same thresholds in the validation cohort. Endoscopists with higher EBR (≥43.8%) had a lower risk of missed cancer compared with those in the lower EBR group (odds ratio, 0.44; 95% CI, 0.20-1.00; P = .049).

CONCLUSIONS

The EBR parameter is highly variable among endoscopists and is associated with efficacy in GPC detection and the rate of missed GCs.

Characteristics and consequences of missed gastric cancer: A multicentric cohort study

BACKGROUND

Missed gastric cancer (MGC) is poorly documented in Mediterranean populations.

AIMS

(1) To assess the rate, predictors and survival of MGC. (2) To compare MGC and non-MGC tumors.

METHODS

This is a retrospective-cohort study conducted at four centers. MGC was defined as cancer detected within three years after negative esophagogastroduodenoscopy. Gastric adenocarcinomas diagnosed between 2008-2015 were included. Patients with no follow-up were excluded.

RESULTS

During the study period 123,395 esophagogastroduodenoscopies were performed, with 1374 gastric cancers being diagnosed (1.1%). A total of 1289 gastric cancers were finally included. The overall rate of MGC was 4.7% (61/1289, 3.7-6%). A negative esophagogastroduodenoscopy in MGC patients was independently associated with PPI therapy (p < 0.001), previous Billroth II anastomosis (p = 0.002), and lack of alarm symptoms (p < 0.001). The most frequent location for MGC was the gastric body(52.4%). MGCs were smaller than non-MGCs (31 vs 41 mm, p = 0.047), more often flat or depressed (p = 0.003) and less likely to be encountered as advanced disease. Overall 2-year survival was similar between MGC (34.1%) and Non-MGC (35.3 %) (p = 0.59).

CONCLUSION

MGC accounted for nearly five percent of newly-diagnosed gastric adenocarcinomas. Overall survival was poor and not different between MGC and non-MGC.

Establishing a model to measure and predict the quality of gastrointestinal endoscopy

BACKGROUND

Tens of millions of gastrointestinal endoscopic procedures are performed every year in China, but the quality varies significantly and related factors are complex. Individual endoscopist- and endoscopy division-related factors may be useful to establish a model to measure and predict the quality of endoscopy.

AIM

To establish a model to measure and predict the quality of gastrointestinal endoscopic procedures in mainland China.

METHODS

Selected data on endoscopy experience, equipment, facility, qualification of endoscopists, and other relevant variables were collected from the National Database of Digestive Endoscopy of China. The multivariable logistic regression analysis was used to identify the potential predictive variables for occurrence of medical malpractice and patient disturbance. Linear and nonlinear regressions were used to establish models to predict incidence of endoscopic complications.

RESULTS

In 2012, gastroscopy/colonoscopy-related complications in mainland China included bleeding in 4,359 cases (0.02%) and perforation in 914 (0.003%). Endoscopic-retrograde-cholangiopancreatography-related complications included severe acute pancreatitis in 593 cases (0.3%), bleeding in 2,151 (1.10%), perforation in 257 (0.13%) and biliary infection in 4,125 (2.11%). Moreover, 1,313 (5.0%) endoscopists encountered with medical malpractice, and 5,243 (20.0%) encountered with the disturbance from patients. The length of endoscopy experience, weekly working hours, weekly night shifts, annual vacation days and job satisfaction were predictors for the occurrence of medical malpractice and patient disturbance. However, the length of endoscopy experience and the ratio of endoscopists to nurses were not adequate to establish an effective predictive model for endoscopy complications.

CONCLUSION

The workload and job satisfaction of endoscopists are valuable predictors for medical malpractice or patient disturbance. More comprehensive data are needed to establish quality-predictive models for endoscopic complications.

Linked Color Imaging and Blue Laser Imaging for Upper Gastrointestinal Screening

White light imaging (WLI) may not reveal early upper gastrointestinal cancers. Linked color imaging (LCI) produces bright images in the distant view and is performed for the same screening indications as WLI. LCI and blue laser imaging (BLI) provide excellent visibility of gastric cancers in high color contrast with respect to the surrounding tissue. The characteristic purple and green color of metaplasias on LCI and BLI, respectively, serve to increase the contrast while visualizing gastric cancers regardless of a history of Helicobacter pylori eradication. LCI facilitates color-based recognition of early gastric cancers of all morphological types, including flat lesions or those in an H. pylori-negative normal background mucosa as well as the diagnosis of inflamed mucosae including erosions. LCI reveals changes in mucosal color before the appearance of morphological changes in various gastric lesions. BLI is superior to LCI in the detection of early esophageal cancers and abnormal findings of microstructure and microvasculature in close-up views of upper gastrointestinal cancers. Excellent images can also be obtained with transnasal endoscopy. Using a combination of these modalities allows one to obtain images useful for establishing a diagnosis. It is important to observe esophageal cancers (brown) using BLI and gastric cancers (orange) surrounded by intestinal metaplasia (purple) and duodenal cancers (orange) by LCI.

Rate of missed oesophageal cancer at routine endoscopy and survival outcomes: A multicentric cohort study

Background

Missed oesophageal cancer (MEC) at upper gastrointestinal endoscopy (UGE) is poorly documented.

Objective

The objectives of this study were: (1) to assess the rate, predictors and survival of MEC; (2) to compare MEC and non-MEC tumours.

Methods

This was a retrospective cohort study conducted at four tertiary centres. Oesophageal cancers (ECs) diagnosed between 2008 and 2015 were included. Patients with a premalignant condition (Barrett, achalasia), prior diagnosis of EC or oesophagogastric junction tumour of gastric origin were excluded. MEC was defined as EC detected within 36 months after negative UGE.

Results

123,395 UGEs were performed during the study period, with 502 ECs being diagnosed (0.4%). A total of 391 ECs were finally included. Overall MEC rate was 6.4% (95% confidence intervals (CI): 4.4-9.3%). The interval between negative and diagnostic UGE was less than 2 years in 84% of the cases. Multivariate analysis showed that a negative endoscopy was associated with proton pump inhibitor (PPI) therapy and less experienced endoscopists. MEC was smaller than non-MEC at diagnosis (25 versus 40 mm, p = 0.021), more often flat or depressed (p = 0.013) and less frequently diagnosed as metastatic disease (p = 0.013). Overall 2-year survival rate was similar for MEC (20%) and non-MEC (24.1%) (p = 0.95).

Conclusions

MEC accounted for 6.4% of all ECs and was associated with poor survival. High-quality UGE and awareness of MEC may help to reduce its incidence.

Differences in upper gastrointestinal neoplasm detection rates based on inspection time and esophagogastroduodenoscopy training

Background and study aims  Esophagogastroduodenoscopy (EGD) has utility in early detection of upper gastrointestinal (UGI) neoplasms. However, previous studies report shorter inspection times and inexperienced endoscopists contribute to overlooking gastric neoplasms. We investigated neoplasm detection rates according to inspection time and extent of EGD training. Patients and methods  In this retrospective observational study, we reviewed routine EGDs for 3,925 consecutive cases between October 2014 and March 2015. We divided the endoscopists into three groups based on median inspection time during EGD without undergoing biopsy. Using cut-off median inspection times of 7 and 10 minutes, three, five, and eight endoscopists were classified into the fast, moderate, and slow groups, respectively. We compared detection rates according to inspection time and the extent of EGD training. Results  The median inspection time among all endoscopists was 9.3 minutes (range, 6.6 - 12.0 min). The detection rate for UGI neoplasms was as follows: fast group, 3.6%; moderate group, 3.3 %; and slow group, 3.1 % ( P  = 0.807). The median inspection time was significantly shorter among the intensive training ≥ 1-year group than among the < 1-year group (< 1-year: median 6.3 min; range 8.2 - 13.9 min, ≥ 1-year: median 8.9 min; range 6.4 - 11.4 min, P  < 0.001). The detection rate for UGI neoplasms was significantly higher among the intensive training ≥ 1-year group than among the < 1-year group (< 1-year: 2.2 %; ≥ 1-year: 3.7 %, OR = 1.65, 95 % CI: 1.02 - 2.68, P  = 0.041). Conclusions  There was no association between inspection times and neoplasm detection rates. The quality of EGD, as measured by neoplasm detection rates, may be improved by ≥ 1-year of intensive training.

Blue Laser Imaging with a Small-Caliber Endoscope Facilitates Detection of Early Gastric Cancer

Conventional endoscopy often misses early gastric cancers with minimal red discoloration because they cannot be distinguished from inflamed mucosa. We treated a patient with a small early gastric cancer that was difficult to diagnose using conventional endoscopy. Conventional endoscopy using a small-caliber endoscope showed only subtle red discoloration of the gastric mucosa. However, blue laser imaging showed a clearly discolored area measuring 10 mm in diameter around the red lesion, which was distinct from the surrounding inflamed mucosa. Irregular vessels on the tumor surface (suspicious for early gastric cancer) were observed even with small-caliber endoscopy. Biopsy revealed a well-moderately differentiated tubular adenocarcinoma, and endoscopic submucosal dissection was performed. Histopathological examination of the specimen confirmed well-moderately differentiated adenocarcinoma localized to the mucosa with slight depression compared to the surrounding mucosa, consistent with the endoscopic findings. This small early gastric cancer became clearly visible with blue laser imaging using small-caliber endoscopy.

Improving the mucosal visualization at gastroscopy: a systematic review and meta-analysis of randomized, controlled trials reporting the role of Simethicone ± N-acetylcysteine

Background

The objective of this article is to study the role of Simethicone ± N-acetylcysteine in improving the mucosal visualization during oesophago-gastro-duodenoscopy (OGD).

Methods

The data retrieved from the published randomized controlled trials (RCTs) reporting the role of Simethicone ± N-acetylcysteine during OGD was analysed using the principles of meta-analysis. The summated outcome of continuous variables was expressed as standardized mean difference (SMD) and dichotomous data was presented in odds ratio (OR).

Results

Three RCTs on 654 patients reported OGD with and without pre-procedure oral administration of Simethicone ± N-acetylcysteine evaluating visibility as good or excellent in number during the procedure. In the random effects model analysis using the statistical software Review Manager 5.3, the use of Simethicone ± N-acetylcysteine was associated with improved (OR, 0.43; 95% CI, 0.28, 0.68; z=3.65; P=0.0003) mucosal visibility. Four RCTs on 364 patients reported OGD with and without pre-procedure oral administration of Simethicone ± N-acetylcysteine evaluating visibility score in study group. In the random effects model analysis using the statistical software Review Manager 5.3, the use of Simethicone ± N-acetylcysteine was associated with improved (SMD, -1.66; 95% CI, -1.93, -1.40; z=12.25; P=0.00001) mucosal visibility score compared to no-Simethicone group.

Conclusions

The findings of current study on 1,099 patients successfully demonstrate that the pre-procedure oral administration of Simethicone ± N-acetylcysteine improves mucosal visualization and mucosal visualization score during OGD.

Natural history of gastric cancer from a retrospective review of endoscopic images of older patients with interval gastric cancer

AIM

Interval gastric cancers (IGC) are defined as those diagnosed after negative results of endoscopy carried out within the past 10 years. We aimed to investigate the characteristics of IGC and the natural history of gastric cancer (GC) from a retrospective view of endoscopic images of older patients with IGC.

METHODS

We retrospectively reviewed endoscopic images of 240 patients with GC who were aged >60 years. We compared past endoscopic images with newer ones, in which GC was diagnosed. IGC were classified into two categories: missed cancers and new cancers.

RESULTS

Of the 240 patients with GC, 32 had past endoscopic images that qualified for a precise review. A total of 14 cases involved new cancers, whereas 18 involved missed cancers. Most of the IGC were stage I for at least 2 years; however, a small subset was unresectable at >2 years after a negative endoscopy. Furthermore, the rate of endoscopic treatment was significantly higher for IGC compared with that for non-IGC.

CONCLUSIONS

In people aged >60 years, most IGC remain in an early stage for at least 2 years; however, at >2 years after a negative endoscopy, some are unresectable. These results suggest that most early-stage GC will not develop into advanced cancers within 2 years; thus, a 2-year interval might be within the permissible range for patients with negative endoscopy results for any lesions. Geriatr Gerontol Int 2018; 18: 997-1002.

Quality standards in upper gastrointestinal endoscopy: a position statement of the British Society of Gastroenterology (BSG) and Association of Upper Gastrointestinal Surgeons of Great Britain and Ireland (AUGIS)

This document represents the first position statement produced by the British Society of Gastroenterology and Association of Upper Gastrointestinal Surgeons of Great Britain and Ireland, setting out the minimum expected standards in diagnostic upper gastrointestinal endoscopy. The need for this statement has arisen from the recognition that while technical competence can be rapidly acquired, in practice the performance of a high-quality examination is variable, with an unacceptably high rate of failure to diagnose cancer at endoscopy. The importance of detecting early neoplasia has taken on greater significance in this era of minimally invasive, organ-preserving endoscopic therapy. In this position statement we describe 38 recommendations to improve diagnostic endoscopy quality. Our goal is to emphasise practices that encourage mucosal inspection and lesion recognition, with the aim of optimising the early diagnosis of upper gastrointestinal disease and improving patient outcomes.

Linked color imaging (LCI), a novel image-enhanced endoscopy technology, emphasizes the color of early gastric cancer

BACKGROUND AND STUDY AIMS

 Linked color imaging (LCI) and blue laser imaging (BLI) are novel image-enhanced endoscopy technologies with strong, unique color enhancement. We investigated the efficacy of LCI and BLI-bright compared to conventional white light imaging (WLI) by measuring the color difference between early gastric cancer lesions and the surrounding mucosa.

PATIENTS AND METHODS

 Images of early gastric cancer scheduled for endoscopic submucosal dissection were captured by LCI, BLI-bright, and WLI under the same conditions. Color values of the lesion and surrounding mucosa were defined as the average of the color value in each region of interest. Color differences between the lesion and surrounding mucosa (ΔE) were examined in each mode. The color value was assessed using the CIE L*a*b* color space (CIE: Commission Internationale d'Eclairage).

RESULTS

 We collected images of 43 lesions from 42 patients. Average ΔE values with LCI, BLI-bright, and WLI were 11.02, 5.04, and 5.99, respectively. The ΔE was significantly higher with LCI than with WLI ( P  < 0.001). Limited to cases of small ΔE with WLI, the ΔE was approximately 3 times higher with LCI than with WLI (7.18 vs. 2.25). The ΔE with LCI was larger when the surrounding mucosa had severe intestinal metaplasia ( P  = 0.04). The average color value of a lesion and the surrounding mucosa differed. This value did not have a sufficient cut-off point between the lesion and surrounding mucosa to distinguish them, even with LCI.

CONCLUSION

 LCI had a larger ΔE than WLI. It may allow easy recognition and early detection of gastric cancer, even for inexperienced endoscopists.