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

The effect of incorporating domain knowledge with deep learning in identifying benign and malignant gastric whitish lesions: A retrospective study

BACKGROUND AND AIM

Early whitish gastric neoplasms can be easily misdiagnosed; differential diagnosis of gastric whitish lesions remains a challenge. We aim to build a deep learning (DL) model to diagnose whitish gastric neoplasms and explore the effect of adding domain knowledge in model construction.

METHODS

We collected 4558 images from two institutions to train and test models. We first developed two sole DL models (1 and 2) using supervised and semi-supervised algorithms. Then we selected diagnosis-related features through literature research and developed feature-extraction models to determine features including boundary, surface, roundness, depression, and location. Then predictions of the five feature-extraction models and sole DL model were combined and inputted into seven machine-learning (ML) based fitting-diagnosis models. The optimal model was selected as ENDOANGEL-WD (whitish-diagnosis) and compared with endoscopists.

RESULTS

Sole DL 2 had higher sensitivity (83.12% vs 68.67%, Bonferroni adjusted P = 0.024) than sole DL 1. Adding domain knowledge, the decision tree performed best among the seven ML models, achieving higher specificity than DL 1 (84.38% vs 72.27%, Bonferroni adjusted P < 0.05) and higher accuracy than DL 2 (80.47%, Bonferroni adjusted P < 0.001) and was selected as ENDOANGEL-WD. ENDOANGEL-WD showed better accuracy compared with 10 endoscopists (75.70%, P < 0.001).

CONCLUSIONS

We developed a novel system ENDOANGEL-WD combining domain knowledge and traditional DL to detect gastric whitish neoplasms. Adding domain knowledge improved the performance of traditional DL, which provided a novel solution for establishing diagnostic models for other rare diseases potentially.

Risk factors of missed early gastric cancer in endoscopic resected population: a retrospective, case-control study

BACKGROUND

Missed early gastric cancer (MEGC) is prevalent during esophagogastroduodenoscopy (EGD), which is the first-line recommended strategy for detecting early gastric cancer (EGC). Hence, we explored the risk factors for MEGC and different types of MEGC, based on the endoscopic resected population.

METHODS

This retrospective, case-control study was conducted at Nanjing Drum Tower Hospital (NJDTH). We included patients who were diagnosed with EGC during screening EGD, underwent endoscopic resection, and were confirmed by postoperative pathology at the NJDTH from January 2014 to December 2021, and classified them into different types according to the different root causes of misses. Univariable, multivariable, subgroup and propensity score analyses were used to explore the risk factors for MEGC and different types of MEGC.

RESULTS

A total of 447 patients, comprising 345 with initially detected early gastric cancer (IDEGC) and 102 with MEGC, were included in this study. Larger size (≥ 1 cm) (OR 0.45, 95% CI 0.27-0.74, P = 0.002) and invasion depth of submucosa (OR 0.26, 95% CI 0.10-0.69, P = 0.007) were negatively associated with MEGC. Use of sedation (OR 0.32, 95% CI 0.20-0.52, P < 0.001) and longer observation time (OR 0.60, 95% CI 0.37-0.96, P = 0.034) exhibited protective effect on MEGC.

CONCLUSIONS

Smaller and more superficial EGC lesions are more susceptible to misdiagnosis. The use of sedation and prolonged observation time during EGD could help reduce the occurrence of MEGC.

Epstein-Barr Virus and Clinico-Endoscopic Characteristics of Gastric Remnant Cancers Compared to Proximal Non-Remnant Cancers: A Population-Based Study

Epstein-Barr virus (EBV) is associated with 5-10% of gastric cancers and is recognized as a distinct molecular subtype. EBV positivity is particularly high in gastric remnant cancer (GRC), which may inform the mode of clinical presentation and findings at endoscopy. Most data are from the East, and the question remains how this applies to a Western cohort. We conducted a population-based study in Central Norway, 2001-2016. Patients with GRC (n = 78) and patients with non-GRC proximally located cancer and available tissue for EBV status (n = 116, control group) were identified from the Norwegian Cancer Registry. Relevant data were collected from the individual patient journals. EBV status was assessed using in situ hybridization. The median latency time from the distal gastrectomy to GRC was 37.6 (range 15.7-68.0) years. GRC more often presented with GI bleeding, 31.0% vs. 16.1%, p = 0.017, and at endoscopy more seldom with an ulcer, 19.7% vs. 38.2%, p = 0.012, or a tumour, 40.8% vs. 66.4%, p < 0.001. For GRC, 18.7% were EBV-positive compared to 6.0% among the controls, p = 0.006. EBV status was not associated with patient age, sex, or Lauren histological type. No difference in long-term survival rates between GRC and controls was found or between EBV-positive vs. -negative GRCs. In conclusion, a higher proportion of GRC cases, compared to controls, are EBV positive, indicating different causative factors. The mode of clinical presentation and findings at endoscopy were more subtle in the patients with GRC.

Clinical and molecular characteristics of early-onset vs average-onset esophagogastric cancer

BACKGROUND

The rate of esophagogastric cancer is rising among individuals under 50 years of age. It remains unknown whether early-onset esophagogastric cancer represents a unique entity. This study investigated the clinical and molecular characteristics of early-onset and average-onset esophagogastric cancer .

METHODS

We reviewed the Memorial Sloan Kettering Cancer Center gastric, esophageal, and gastroesophageal junction cancer database. Associations between baseline characteristics and tumor and germline molecular alterations were compared between those with early-onset and average-onset esophagogastric cancer using Fisher exact tests and the Benjamini-Hochberg method for multiple-hypothesis correction.

RESULTS

We included 1123 patients with early-onset esophagogastric cancer (n = 219; median age = 43 years [range = 18-49 years]) and average-onset esophagogastric cancer (n = 904; median age = 67 years [range = 50-94 years]) treated between 2005 and 2018. The early-onset group had more women (39% vs 28%, P = .002). Patients with early-onset esophagogastric cancer were more likely to have a gastric primary site (64% vs 44%, P < .0001). The signet ring cell and/or diffuse type was 3 times more common in the early-onset esophagogastric cancer group (31% vs 9%, P < .0001). Early-onsite tumors were more frequently genomically stable (31% vs 18%, P = .0002) and unlikely to be microsatellite instability high (2% vs 7%, P = .003). After restricting to adenocarcinoma and signet ring cell and/or diffuse type carcinomas, we observed no difference in stage (P = .40) or overall survival from stage IV diagnosis (median = 22.7 vs 22.1 months, P = .78).

CONCLUSIONS

Our study supported a preponderance of gastric primary disease sites, signet ring histology, and genomically stable molecular subtypes in early-onset esophagogastric cancer. Our findings highlight the need for further research to define the underlying pathogenesis and strategies for early detection and prevention.

Gastric remnant cancer and long-term survival in Central Norway 2001 to 2016 - A population-based study

INTRODUCTION

Gastric remnant cancer (GRC) has been defined as a distinct clinical entity and is reported to account for 1-8% of all gastric cancers. We aimed to characterize GRC patients and assess survival in a Western population.

METHODS

Retrospective population-based cohort study including 1217 patients diagnosed with gastric adenocarcinoma in Central Norway 2001-2016. GRCs (n = 78) defined as adenocarcinomas arising in the residual stomach after distal gastrectomy were compared to non-GRC (n = 1139) and to proximal non-GRC (n = 595).

RESULTS

78 (6.4 %) gastric cancers were GRC. The annual number and proportion of GRC declined during the study period (p = 0.003). Median latency from distal gastrectomy to GRC diagnosis was 37.6 years (15.7-68.0) and previous Billroth II reconstruction was most common (87.7%). Compared to controls, GRC patients were more frequently males (83.3%), diagnosed in earlier TNM stages and were older at diagnosis. A smaller proportion of GRC patients received perioperative or palliative chemotherapy, but the R0/R1resection rate of 41.0% was no different from non-GRC patients. Overall median survival for GRC patients irrespective of treatment was 7.0 months, which did not differ from non-GRCs or proximal non-GRC. In multivariate analyses TNM stage and age were independently associated with mortality, whereas GRC per se was not.

CONCLUSIONS

Numbers of GRCs declined during the study period, but the latency between distal gastrectomy and GRC diagnosis was long. GRC patients were more frequently male and older than other gastric cancer patients. GRC was not independently associated with survival after adjusting for TNM stage and tumor location.

Optimal timing of simethicone administration prior to upper endoscopy: A multicenter, single-blind, randomized controlled trial

Background and study aims Simethicone is useful as premedication for upper endoscopy because of its antifoaming effects. We aimed to evaluate the effect of timing of simethicone administration on mucosal visibility. Patients and methods In this multicenter, randomized, endoscopist-blinded study, patients scheduled for upper endoscopy were randomized to receive 40 mg simethicone at the following time points prior to the procedure: 20 to 30 minutes (early group), 0 to 10 minutes (late group) or 20 mg simethicone at both time points (split-dose group). Images were taken from nine predefined locations in the esophagus, stomach, and duodenum before endoscopic flushing. Each image was scored on mucosal visibility by three independent endoscopists on a 4-point scale (lower scores indicating better visibility), with adequate mucosal visibility defined as a score ≤ 2. Primary outcome was the percentage of patients with adequate total mucosal visibility (TMV), reached if all median subscores for each location were ≤ 2. Results A total of 386 patients were included (early group: 132; late group: 128; split-dose group: 126). Percentages of adequate TMV were 55%, 42%, and 61% in the early, late, and split-dose group, respectively ( P < 0.01). Adequate TMV was significantly higher in the split-dose group compared to the late group ( P < 0.01), but not compared to the early group ( P = 0.29). Differences between groups were largest in the stomach, where percentages of adequate mucosal visibility were higher in the early (68% vs 53%, P = 0.03) and split-dose group (69% vs 53%, P = 0.02) compared to the late group. Conclusions Mucosal visibility can be optimized with early simethicone administration, either as a single administration or in a split-dose regimen.

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.

Interval Advanced Gastric Cancer After Negative Endoscopy

BACKGROUND & AIMS

Esophagogastroduodenoscopy (EGD) is effective in reducing gastric cancer mortality through detection of early-stage cancer in areas with a high prevalence of gastric cancer. Although the risk of post-endoscopy advanced gastric cancer (AGC) is low, interval AGC remains a concern. We investigated the characteristics and predictors of interval AGC after negative EGD.

METHODS

We included 1257 patients with gastric cancer within 6 to 36 months of a "cancer-negative" index EGD between 2005 and 2021 at a tertiary university hospital in South Korea. Observation time on the index EGD was used as a quality indicator. We compared the clinical and endoscopic characteristics and quality indicators between interval AGC and screen-detected early gastric cancer (EGC).

RESULTS

Within 6 to 36 months of negative EGD, 102 AGCs (8.1%) and 1155 EGCs (91.9%) were identified. The percentage of patients with shorter observation time (<3 minutes) in the index EGD was higher in the interval AGC group than in the detected EGC group (P = .002). A multivariable analysis comparing screen-detected EGD and interval AGC was adjusted for age, sex, family history of gastric cancer, H. pylori status, endoscopic findings, and endoscopy-related factors including gastric observation time and interval time. A shorter observation time (<3 minutes) (odds ratio, 2.27; 95% confidence interval, 1.20-4.30), and interval time >2 years (odds ratio, 1.84; 95% confidence interval, 1.04-3.24) were associated with an increased risk of interval AGC.

CONCLUSION

A shorter observation time during index EGD is an important predictor of interval AGC. Further, withdrawal time longer than 3 minutes may be a quality indicator for screening EGD.

The Visible Stomach: Elusive Diffuse-Type Adenocarcinoma Presents With Gastric Outlet Obstruction

The diagnosis of diffuse-type gastric cancers may be challenging due to their submucosal infiltration. A male in his early 60s was diagnosed with signet-ring cell adenocarcinoma of the diffuse type based on a biopsy from a perforated gastric ulcer. Postoperative workup was negative, including repeated esophagogastroduodenoscopy, gastric biopsies, tumor markers, computed tomography (CT), and positron emission tomography (PET). Six months after the operation, the patient presented to our center with abdominal discomfort and nausea. The clinical examination showed an enlarged visible stomach due to gastric outlet obstruction. The patient underwent total gastrectomy after confirmation of malignancy using an intraoperative frozen section. However, the tumor was already advanced locally and regionally. Confirmed malignancy in biopsies from perforated gastric ulcers should be never considered false positivity. To avoid missing a diffuse gastric cancer, endoscopic biopsies should be obtained using advanced techniques such as submucosal dissection under endosonographic guidance.

Quality indicators in esophagogastroduodenoscopy

Esophagogastroduodenoscopy (EGD) has been used to diagnose a wide variety of upper gastrointestinal diseases. In particular, EGD is used to screen high-risk subjects of gastric cancer. Quality control of EGD is important because the diagnostic rate is examiner-dependent. However, there is still no representative quality indicator that can be uniformly applied in EGD. There has been growing awareness of the importance of quality control in improving EGD performance. Therefore, we aimed to review the available and emerging quality indicators for diagnostic EGD.

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.