Introduction

In recent years, as the rate of Helicobacter pylori (H. pylori) infection has declined, the number of H. pylori-related gastric neoplasms (HpRGNs) has decreased. Although the number of H. pylori-naïve gastric neoplasms (HpNGNs) is estimated to be small compared to that of HpRGNs, the exact prevalence has not been unknown. Therefore, the effectiveness of screening by esophagogastroduodenoscopy (EGD) in cohorts with low H. pylori infection rate has not been revealed.

Aims & Methods

The aim of this study is (1) to determine age-related HpNGN prevalence by using a large-scale Japanese cohort and (2) to develop the optimal EGD screening strategy to detect HpNGNs in terms of screening efficiency.
Database of EGD for health checkup from 12 institutions in Japan between 2016 and 2022 was retrospectively reviewed. Detailed information on identified HpNGNs was investigated; age, sex, pathological diagnosis (pure signet ring cell carcinoma (PSRCC), gastric adenocarcinomas of the fundic gland type (GA-FG), foveolar gastric adenoma-raspberry type (FGA-raspberry type), and undifferentiated type cancer), lesion size, lesion depth, lymphovascular invasion, and presence of lymph node metastasis, and EGD images. EGD images of patients who underwent multiple EGDs in the past were followed retrospectively for changes in tumor size. Tumor growth speed, missing rate, age-related HpNGNs prevalence, and detection threshold size were calculated from database. A virtual cohort of 100,000 births in the first year and thereafter reflecting the Japanese fertility trend was constructed based on these parameters. In this virtual cohort for 70 years of follow-up, tumor detection rates and number-need-to-test (NNT) for PSRCC, GA-FG, and undifferentiated cancers at different EGD screening start ages (40, 45, and 50 years) and screening intervals (2, 5, and 10 years) were compared.

Results

A total of 519,368 EGD cases were initially screened and 113 HpNGN lesions were detected in 108 patients (0.021%). HpNGN was found in all generations from 20s to 80s (0.011-0.028%). The age-related prevalence varied widely by HPNGN type; the prevalence of PSRCC was highest (0.022%) in 60s, but the prevalence of GA-FG gradually increased after the age of 50 and was not detected in people under 40. Additionally, undifferentiated cancer was discovered in people in their 30s and 50s, but not in people over 60. Tumor characteristics were analyzed for the construction of the simulation model by investigating the 97 of those lesions (34 PSRCC cases, 26 GA-FG cases, 30 FGA-raspberry type cases, and 7 undifferentiated type cases). The tumor growth rate was 2.5 mm/year for PSRCC, 2.7 mm/year for GA-FG, 1.2 mm/year for FGA-raspberry type and 11.7 mm/year for undifferentiated carcinoma. The missed rate was 46.1% for PSRCC, 65.2% for GA-FG, 56.5% for FGA-raspberry type and 17.0% for undifferentiated type. Among the strategies with detection rates of 50% or higher in the virtual cohort, the NNT of the 5-year interval screening strategy starting at age 45 years was the lowest for all tumor types (PSRCC 4.89, GA-FG 9.92, undifferentiated cancer 4.69). By adopting this strategy, most of HpNGNs were detected in less than 20 mm in size and the deep submucosa invasion rate was less than 30%.

Conclusion

A large-scale Japanese cohort demonstrated that prevalence of HpNGN was very low (0.021%). Mathematical simulation modeling revealed that the strategy of screening every 5 years starting at age 45 was most efficient to detect HpNGN.

Introduction

Early detection of gastric neoplasms in esophagogastroduodenoscopy (EGD) remains challenging due to the subtle and indistinct appearance of the lesions. In addition to white light imaging (WLI), image-enhanced endoscopy techniques, such as linked color imaging (LCI), are commonly used to detect such lesions. Recently, a computer-aided detection (CADe) system compatible with WLI and LCI (CAD EYE; Fujifilm Co., Tokyo, Japan) has been developed. However, evidence of its effectiveness in real-world clinical settings remains limited.

Aims & Methods

We conducted a multicenter, non-randomized confirmatory trial to evaluate the performance of CAD EYE in detecting gastric neoplasms. Between July 2023 and January 2024, patients undergoing EGD for known early gastric neoplasms were recruited at four institutions in Japan. While systematically observing the entire stomach with WLI and LCI, we investigated whether these lesions were detected by CAD EYE. The primary outcome was the sensitivity of CAD EYE (WLI-CADe and LCI-CADe) in detecting tumors. Secondary outcomes included identifying tumor characteristics and factors associated with missed detections by CAD EYE. To determine the sample size, we presumed the sensitivity of CAD EYE to be 95% based on pre-approval data, with a threshold set at 90%. The number of lesions required was calculated to be 150, ensuring that the lower limit of the 95% confidence interval (CI) exceeded the threshold of 90%. Assuming one lesion per patient and accounting for a 5% dropout rate, we recruited a total of 160 patients.

Results

A total of 174 lesions from 162 patients (mean age: 73.7±9.5 years, male: 69.7%) were analyzed. Current or past history of Helicobacter pylori (H. pylori) infection was observed in 158 patients (97.5%). The mean tumor diameter was 15.1 ± 11.3 mm, and the morphology consisted of 6 protruded, 51 flat elevated, and 117 flat types. Histology included 151 differentiated adenocarcinoma, 20 undifferentiated adenocarcinoma, 2 adenocarcinoma of fundic-gland type, and 1 tubular adenoma. The sensitivities of WLI-CADe and LCI-CADe in detecting tumors were 92.0% (95% CI: 86.9%–95.5%) and 96.5% (95% CI: 92.6%–98.7%), respectively. The sensitivity of LCI-CADe met expectations, as the lower limit of the 95% CI exceeded the threshold of 90%; however, WLI-CADe failed to meet the same standard. In WLI-CADe, lesions located on the anterior/posterior wall were missed significantly more often than those on the greater/lesser curvature (13.9% [11 of 79] vs. 3.2% [3 of 95]; P = 0.020); whereas no difference was observed in LCI-CADe. Other factors, such as H. pylori infection status, tumor morphology, location, and histology, showed no differences between lesions detected and missed by WLI-CADe and LCI-CADe.

Conclusion

The use of CADe with LCI demonstrated satisfactory sensitivity in detecting gastric neoplasms in real-world clinical settings, suggesting its potential to assist endoscopists in tumor detection. However, CADe with WLI did not meet the expected standards, possibly due to limitations, such as detecting lesions located on the anterior/posterior wall.

Disclosure

CAD EYE was temporarily provided by Fujifilm Co. Osamu Dohi has received a research grant, not related to this study, from Fujifilm Co. The remaining authors declare no conflicts of interest.

Introduction

The risk of gastric cancer is expected to decrease with reduced Helicobacter pylori (H. pylori) infection rate. Although periodic endoscopic screening for gastric cancer is widely performed in East Asia, the optimal screening strategy remains unclear. Cost-effectiveness analysis (CEA) is an effective method to objectively compare different screening methods. However, no studies have compared the cost-effectiveness of endoscopy-based screening strategies.

Aims & Methods

This study aimed to determine the most cost-effective endoscopic screening strategy for the detection and treatment of gastric cancer in a modern Japanese cohort. This study consisted of two phases: clinical data collection and analysis, followed by simulation model development. The following data was retrospectively extracted from participants who received screening endoscopy between April 2019 and March 2023: age, H. pylori infection status, presence of intestinal metaplasia, pathological diagnosis of gastric cancer, and the interval between the most recent endoscopies. A Markov state transition model was constructed based on the cohort data. In this model, the prevalence of H. pylori infection and intestinal metaplasia, the transition probabilities between each state, and the probabilities of incidence of gastric cancer and treatment were defined. In the base-case analysis, the cost-effectiveness of 15 strategies with different starting ages (40/50/60 years) and screening intervals (1/2/3/4/5 years) was compared. The net monetary benefit (NMB) and incremental cost-effectiveness ratio (ICER) of quality-adjusted life-years (QALY) gained by treatment were used as outcomes. The NMB is a measure of the difference between the cost required for a strategy and the cost threshold for the same effect; the larger the NMB of a strategy, the more cost-effective it is. In contrast, a lower ICER is considered more cost-effective.

Results

A simulation model was constructed based on the cohort data of 94,137 participants (mean age 54.5 years, males 57.9%; 74.4% H. pylori-naïve, 94.2% intestinal metaplasia-negative). The results of the base-case analysis showed that the screening strategy of 4-year intervals starting at the age of 40 years had the highest net monetary benefit (97,401,578 yen) (Table). Based on the Monte Carlo simulation, the cost-effectiveness acceptability curve demonstrated that the 4-year interval screening strategy starting at the age of 40 years was superior to the other strategies when the willingness-to-pay was set at 5,000,000 yen. In one-way sensitivity analysis with a varying probability of H. pylori infection status transition, the incremental cost-effectiveness ratio was superior in the screening strategy every 4 years, starting at age 40 years.

Conclusion

Gastric cancer screening strategies can be modified in terms of cost-effectiveness in a modern Japanese cohort. Our simulation showed that endoscopic screening at 4-year intervals starting at 40 years was the most cost-effective method.

Disclosure

The authors declare that there is no conflict of interest.

Introduction

The implementation of computer-aided detection (CAD) devices in esophagogastroduodenoscopy (EGD) could autonomously identify gastric precancerous lesions and neoplasms, and reduce the miss rate of gastric neoplasms in prospective trials. However, there is still insufficient evidence of their use in real-life clinical practice.

Aims & Methods

A real-world, two-center, large-volume, pragmatic study was conducted at Wenzhou Central Hospital (WCH) and Renmin Hospital of Wuhan University (RHWU). Random biopsy and target biopsy were adopted and CAD devices were applied in 2019 and 2021 at WCH and RHWU, respectively. We compared differences in gastric precancerous and neoplasm detection of EGD before and after the use of CAD devices in the first half of the year.

Results

A total of 33885 patients were included and 32886 patients were ultimately analysed. In WCH of which biopsy rate > 95%, with the implementation of CAD, more early gastric cancer detection rate (0.35% vs. 0.59%, p=0.028, OR(95%CI) = 1.65(1.06-2.60)) was found while gastric neoplasm detection rate (1.39% vs. 1.36%, p=0.897, OR(95%CI) = 0.98(0.76-1.26)) remained stable. In RHWU of which biopsy rate < 20%, the gastric neoplasm detection rate (1.78% vs. 3.23%, p<0.001,OR(95%CI) = 1.84(1.33-2.54)) nearly doubled after the implementation of CAD while there was no significant change in the early gastric cancer detection rate.

Conclusion

In our study of large-volume tertiary centers with varied biopsy strategies, we observed that diagnostic benefits differed depending on the application conditions, and each biopsy approach offered distinct advantages. In healthcare center with a high biopsy rate exceeding 95%, the CAD device appeared to enable endoscopists to conduct more precise, targeted biopsies, leading to an increased detection of early gastric cancer. However, the overall gastric neoplasm detection rate remained consistent. In contrast, at institutions like RHWU, which employed a targeted biopsy strategy resulting in an average biopsy rate less than 20%, the incorporation of CAD in routine EGD demonstrated a notable increase in the overall gastric neoplasm detection rate, particularly for low-grade intraepithelial neoplasia.

References

1. Sung, H., et al., Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA Cancer J Clin, 2021. 71(3): p. 209-249.
2. Correa, P., Human gastric carcinogenesis: a multistep and multifactorial process--First American Cancer Society Award Lecture on Cancer Epidemiology and Prevention. Cancer Res, 1992. 52(24): p. 6735-40.
3. Leung, W.K. and J.J. Sung, Review article: intestinal metaplasia and gastric carcinogenesis. Aliment Pharmacol Ther, 2002. 16(7): p. 1209-16.
4. Correa, P., et al., A model for gastric cancer epidemiology. Lancet, 1975. 2(7924): p. 58-60.
5. Ling, T., et al., A deep learning-based system for identifying differentiation status and delineating the margins of early gastric cancer in magnifying narrow-band imaging endoscopy. Endoscopy, 2021. 53(5): p. 469-477.
6. Gong, E.J., et al., Deep learning-based clinical decision support system for gastric neoplasms in real-time endoscopy: development and validation study. Endoscopy, 2023. 55(8): p. 701-708.
7. Wu, L., et al., Deep learning system compared with expert endoscopists in predicting early gastric cancer and its invasion depth and differentiation status (with videos). Gastrointest Endosc, 2022. 95(1): p. 92-104.e3.
8. Guimarães, P., et al., Deep-learning based detection of gastric precancerous conditions. Gut, 2020. 69(1): p. 4-6.

Introduction

Gastroparesis (GP) is a poorly understood condition with current diagnostic tests lacking disease specificity. Gastric per oral endoscopic myotomy (G-POEM) has emerged as a promising treatment for refractory gastroparesis, however up to a third of patients fail to have an improvement in their symptoms.

Aims & Methods

We assessed the ability of Gastric Alimetry®, a new, non-invasive test of gastroduodenal function to enhance patient selection for G-POEM. Data was collected from patients with suspected GP (based on symptoms and scintigraphy), being worked up for G-POEM at Kings College Hospital between November 2022 and September 2023 (REC: 22/LO/0802). G-POEM success was defined as <1 point reduction in GCSI score. Descriptive comparisons were used to explore predictors of improvements in gastroparesis cardinal symptom index (GCSI).

Results

11 patients were assessed (8F, median age 40 interquartile range 32.5-49.5). GCSI scores significantly improved after G-POEM (median difference -1.03, IQR 0.50). Aetiologies of gastroparesis included 5 (45.5%) diabetic, 4 (36.4%) idiopathic, and 2 other aetiologies. Gastric Alimetry spectral analysis showed 2 (18.2%) with high frequencies, 2 (18.2%) with neuromuscular dysfunction (low rhythm stability and/or low amplitude), and 7 (63.6%) with normal spectral metrics. Symptom profiles followed a continuous pattern in 4 (36.4%), sensorimotor in 2 (18.2%), post-gastric in 1 (9.1%) and meal-induced in the remainder (36.4%). High frequency phenotype was associated with treatment failure (2/2, 100%), and neuromuscular phenotype was associated with success (2/2, 100%). The change in GCSI score after G-POEM was significantly lower in the high frequency group compared to the group average (median difference -0.18, IQR 0.18; p = 0.03).The average frequency and rhythm index was 2.9 (0.1) cycles per minute (cpm) and 0.4 (0.2) respectively among responders vs 3.2 (0.4) cpm 0.6 among non-responders.

Conclusion

Gastric Alimetry® is a new, non-invasive test of gastric function with provisional utility in differentiating disease mechanisms in patients with suspected GP. Early data suggests biomarkers for gastric autonomic dysregulation (high slow wave frequencies) were associated with reduced response to G-POEM. Further data are eagerly anticipated to validate these findings and develop more sophisticated predictive models for G-POEM outcomes.

Introduction

Subepithelial lesions (SELs) are frequently detected during esophagogastroduodenoscopy, yet their diagnostic workup remains challenging. Accurate histological characterization is essential for optimal management. Endoscopic ultrasound (EUS) enables both lesion assessment and sampling and is the first-line modality for evaluating SELs >10 mm. However, EUS interpretation is operator-dependent and suffers from suboptimal diagnostic accuracy. This multicenter study aimed to develop and validate a deep learning model for automated detection and classification of upper gastrointestinal SELs, specifically distinguishing leiomyomas from gastrointestinal stromal tumors (GISTs).

Aims & Methods

A convolutional neural network (YOLO11Net) was trained using 57,190 EUS images from 65 patients across five countries (Portugal, USA, Spain, Brazil, and the UK) and five different EUS platforms. The dataset was split into training (70%), validation (20%), and testing (10%) subsets. The model was designed to perform binary classification between GISTs and leiomyomas. Performance was evaluated using accuracy and area under the precision-recall curve (AUC-PR).

Results

The model achieved an overall diagnostic accuracy of 95%. For GIST detection, the AUC-PR was 0.992, and for leiomyomas, 0.982, demonstrating excellent discriminative performance.

Conclusion

This is the first global AI model capable of detecting and differentiating the most prevalent SELs using EUS. The model’s high accuracy and robust AUC-PR values underscore its clinical potential to enhance diagnostic precision and guide targeted tissue sampling. The inclusion of data from multiple devices and international centers strengthens the model's generalizability and reduces demographic and technical bias. Larger, prospective multicenter studies are warranted to validate these findings and support clinical integration.

Introduction

Endoscopic submucosal dissection (ESD) is the gold standard for superficial gastric cancer. Nonetheless, mastering ESD entails a steep learning curve requiring 30-50 procedures to achieve proficiency. An innovative robotic flexible endoscopic platform may have the potential to expedite the learning curve. The primary goal of this study was to compare a novel flexible endoscopic robotic platform (R-ESD) with conventional ESD (C-ESD) for safety and efficacy of removing large gastric lesions. The secondary aim was to compare beginners and expert performance.

Aims & Methods

A prospective comparative trial was conducted between R-ESD and C-ESD using large gastric lesions in an ex-vivo porcine model from November 2023 to January 2024. Four beginners (no or little endoscopic dissection experience) and four experts (> 500 ESD procedures) were assigned to perform 3 R-ESD and 3 C-ESD each during the study period. All were novices on the flexible robotic platform and underwent the same standardized one-day training. The main outcome measures were overall operative time, dissection speed, rates of en-bloc and curative resection (R0), and perforation. Secondary outcomes assessed the performance of beginners versus experts.

Results

In the study period forty-two 5x5cm lesions were resected- 22 R-ESD and 20 C-ESD. Overall the R-ESD and C-ESD groups had similar mean operative time (75.0 [SD 26.0] minutes versus 76.5 [36.3] minutes, respectively) and dissection speed (0.65 [0.21]cm²/min R-ESD versus 0.68 [0.48]cm²/min C-ESD; p=0.798). 100% of R-ESD were completed en-bloc and with an R0 resection, while the C-ESD group had a 95% en-bloc and 85% R0 resection rate (p>0.05). The perforation rate in R-ESD was 0%, compared to 10% in C-ESD cases.While the disparity between experts and novices was notable for C-ESD, within the R-ESD cohort beginners demonstrated better operative times and dissection speeds, with rates of perforation, en-bloc and curative resection (R0) similar to experts, (Table 1).

Table1. Comparison between convention endoscopic submucosal dissection (ESD) performed by experts and robotic ESD performed by beginners. Data are reported as mean (standard deviation) value. A comparison was performed by a Two Sample T-Test. Data are reporting as mean (Standard deviation). Abbreviation: ESD=Endoscopic submucosal dissection; C-ESD= Conventional ESD; R-ESD= Robot-assisted ESD.

	Beginners	Expert	p
	R-ESD	C-ESD
N	12	10
Time (min)	57.8 (17.1)	52.6 (17.4)	0.489
Area (cm2)	42.1 (10.2)	42.9 (7.7)	0.840
Speed (cm2/min)	0.77 (0.20)	0.92 (0.43)	0.293
Perforation	0/12	0/10	1
Muscle Injury	0/12	0/10	1
R0 Dissection	12/12	10/10	1
En bloc Dissection	12/12	10/10	1

Conclusion

Robotic ESD using a novel flexible endoscopic robotic platform proved to be safe, feasible, and equally effective as conventional ESD for managing large gastric lesions. The flexible endoscopic robotic platform empowered beginners to achieve safety and efficacy comparable to experts after just three procedures. This platform holds significant potential to democratize ESD, reducing variability among operators and expanding access to endoluminal organ-sparing therapies for patients.

Disclosure

Silvana Perretta is a member of EndoQuest's Clinical Advisory Board
Jacques Marescaux is a member of Endoquest's Scientific Advisory Board