Impact of endoscopic screening on mortality reduction from gastric cancer

Epidemiology and prevention of gastric cancer: A comprehensive review

Gastric cancer is the third most deadly cancer worldwide. Helicobacter pylori (H. pylori) infection and specific diets are key risk factors for this illness, which is more frequent in various nations. Nearly half of the world's population, 4.4 billion, had H. pylori in 2015. East has a higher incidence rate than West. GC may spread to the liver, lungs, and bones. The majority of cases are adenocarcinomas (90%). In 2022, stomach cancer caused 968,784 new cases and 660,175 deaths worldwide. GC accounts for 7% of cancer diagnoses and 9% of deaths. The high death rate of gastric cancer highlights the need for preventative methods to improve prognosis. Early identification via biomarker screening, especially in high-risk groups, may improve outcomes and treatments.

ACG Clinical Guideline: Diagnosis and Management of Gastric Premalignant Conditions

Gastric premalignant conditions (GPMC) are common and include atrophic gastritis, gastric intestinal metaplasia, dysplasia, and certain gastric epithelial polyps. GPMC have an increased risk of progression to gastric adenocarcinoma. Gastric cancer (GC) in the United States represents an important cancer disparity because incidence rates are 2- to 13-fold greater in non-White individuals, particularly early-generation immigrants from regions of high GC incidence. The US 5-year survival rate for GC is 36%, which falls short of global standards and is driven by the fact that only a small percentage of GC in the US is diagnosed in the early, curable stage. This document represents the first iteration of American College of Gastroenterology guidelines on this topic and encompasses endoscopic surveillance for high-risk patients with GPMC, the performance of high-quality endoscopy and image-enhanced endoscopy for diagnosis and surveillance, GPMC histology criteria and reporting, endoscopic treatment of dysplasia, the role of Helicobacter pylori eradication, general risk reduction measures, and the management of autoimmune gastritis and gastric epithelial polyps. There is insufficient evidence to make a recommendation on upper endoscopic screening for GC/GPMC detection in US populations deemed high-risk for GC. Surveillance endoscopy is recommended for individuals at high risk for GPMC progression, as defined by endoscopic, histologic, and demographic factors, typically every 3 years, but an individualized interval may be warranted. H. pylori testing, treatment, and eradication confirmation are recommended in all individuals with GPMC. Extensive high-quality data from US populations regarding GPMC management are lacking, but continue to accrue, and the quality of evidence for the recommendations presented herein should be interpreted with this dynamic context in mind. The GPMC research and education agendas are broad and include high-quality prospective studies evaluating opportunistic endoscopic screening for GC/GPMC, refined delineation of what constitutes "high-risk" populations, development of novel biomarkers, alignment of best practices, implementation of training programs for improved GPMC/GC detection, and evaluation of the impact of these interventions on GC incidence and mortality in the US.

Gastric Cancer Screening in the United States: A Review of Current Evidence, Challenges, and Future Perspectives

Gastric cancer remains a leading cause of cancer-related mortality worldwide. In the United States, gastric cancer incidence and mortality are substantially higher among non-White racial and ethnic groups and new immigrants from high-incidence countries. This is in large part related to the higher prevalence of Helicobacter pylori -associated gastric premalignant changes in these populations. Apart from primary prevention, early detection of gastric cancer is the principal strategy to reduce gastric cancer mortality and improve survival. Extensive evidence in Asian countries has demonstrated the benefits of endoscopic screening in detecting early-stage gastric cancer and reducing gastric cancer-related mortality. By contrast, direct, high-quality US-based data, such as from large clinical trials or observational studies, on important outcomes of gastric cancer screening are still lacking. In this review, we evaluate and summarize the latest global evidence on the epidemiology and predisposing factors of gastric cancer as well as the efficacy, benefits vs. risks, and cost-effectiveness of gastric cancer screening. We further discuss the critical knowledge gaps and challenges in promoting gastric cancer screening in the United States. Dedicated research is urgently needed to enrich the US-based data on gastric cancer primary and secondary prevention to inform clinical practice and reduce gastric cancer-related morbidity and mortality in a cost and resource efficient manner.

GastroHUN an Endoscopy Dataset of Complete Systematic Screening Protocol for the Stomach

Endoscopy is vital for detecting and diagnosing gastrointestinal diseases. Systematic examination protocols are key to enhancing detection, particularly for the early identification of premalignant conditions. Publicly available endoscopy image databases are crucial for machine learning research, yet challenges persist, particularly in identifying upper gastrointestinal anatomical landmarks to ensure effective and precise endoscopic procedures. However, many existing datasets have inconsistent labeling and limited accessibility, leading to biased models and reduced generalizability. This paper introduces GastroHUN, an open dataset documenting stomach screening procedures based on a systematic protocol. GastroHUN includes 8,834 images from 387 patients and 4,729 labeled video sequences, all annotated by four experts. The dataset covers 22 anatomical landmarks in the stomach and includes an additional category for unqualified images, making it a valuable resource for AI model development. By providing a robust public dataset and baseline deep learning models for image and sequence classification, GastroHUN serves as a benchmark for future research and aids in the development of more effective algorithms.

Effectiveness of Risk-Adapted Upper Gastrointestinal Cancer Screening in China: Prospective Cohort Study

Background

Previous studies have proved the effectiveness of endoscopic screening in rural areas; however, long-term, high-quality evidence regarding the effectiveness of risk-adapted upper gastrointestinal cancer (UGC) sequential screening strategies in resource-rich regions is currently lacking.

Objective

The objectives were to validate the effectiveness of risk-adapted sequential screening strategies in UGC prevention and control and assess the potential of sequential screening to lower mortality rates.

Methods

Based on the Cancer Screening Program in Urban China, a prospective, large-scale cohort study based on population was conducted to recruit individuals from 4 cities in China from 2013-2019. Those identified as having a high risk of UGC according to a validated risk-score model were advised to undergo endoscopy tests. Follow-up outcomes were tracked until June 2021. Incidence of UGC, UGC-related mortality, and all-cause mortality were evaluated between the screened and nonscreened cohorts.

Results

The study included 153,079 participants at baseline. In total, 113,916 (74.42%) of the participants were designated as low risk of UGC. The remaining 39,163 (25.68%) participants were deemed to be at high risk of UGC and were offered gastroscopy tests. Among the high-risk participants, 9627 (compliance rate 24.6%) adhered to the gastroscopy tests. Over a median follow-up of 6.05 (IQR 3.06-7.06) years, 622 UGC cases, 180 UGC deaths, and 1958 all-cause death cases were traced. The screened cohort exhibited the highest cumulative incidence of UGC (119.2 per 100,000 person-years), followed by the nonscreened and low-risk cohorts. Obvious reductions in both all-cause mortality and UGC mortality were observed between those who undertook screening (153.7 and 4.7 per 100,000 person-years, respectively) and the nonscreened group (245.3 and 27 per 100,000 person-years, respectively). The screening population showed a significant 36% and 82% reduction in both all-cause mortality (hazard ratio [HR] 0.64, 95% CI 0.49-0.83, P<.001) and UGC mortality (HR 0.18, 95% CI 0.04-0.74, P=.02), respectively, compared to the nonscreened group. Reductions of 35% in all-cause mortality (HR 0.65, 95% CI 0.49-0.86, P=.003) and 81% in UGC mortality (HR 0.19, 95% CI 0.05-0.80, P=.02) were observed in participants aged older than 55 years in the screened group compared to the nonscreened group. The reductions in all-cause mortality and UGC mortality were statistically significant in males (all-cause mortality: HR 0.64, 95% CI 0.47-0.88, P=.005; UGC mortality: HR 0.10, 95% CI 0.01-0.72, P=.02), but significant reductions were not observed in females (all P values were >.05).

Conclusions

Our study suggests the significance of one-off risk-adapted UGC screening in reducing both all-cause mortality and UGC mortality, particularly among high-risk individuals, indicating its effectiveness in UGC prevention and management.

Global incidence and mortality trends of gastric cancer and predicted mortality of gastric cancer by 2035

OBJECTIVE

To study the historical global incidence and mortality trends of gastric cancer and predicted mortality of gastric cancer by 2035.

METHODS

Incidence data were retrieved from the Cancer Incidence in Five Continents (CI5) volumes I-XI, and mortality data were obtained from the latest update of the World Health Organization (WHO) mortality database. We used join-point regression analysis to examine historical incidence and mortality trends and used the package NORDPRED in R to predict the number of deaths and mortality rates by 2035 by country and sex.

RESULTS

More than 1,089,000 new cases of gastric cancer and 769,000 related deaths were reported in 2020. The average annual percent change (AAPC) in the incidence of gastric cancer from 2003 to 2012 among the male population, South Korea, Japan, Malta, Canada, Cyprus, and Switzerland showed an increasing trend (P > 0.05); among the female population, Canada [AAPC, 1.2; (95%Cl, 0.5-2), P < 0.05] showed an increasing trend; and South Korea, Ecuador, Thailand, and Cyprus showed an increasing trend (P > 0.05). AAPC in the mortality of gastric cancer from 2006 to 2015 among the male population, Thailand [3.5 (95%cl, 1.6-5.4), P < 0.05] showed an increasing trend; Malta Island, New Zealand, Turkey, Switzerland, and Cyprus had an increasing trend (P > 0.05); among the male population aged 20-44, Thailand [AAPC, 3.4; (95%cl, 1.3-5.4), P < 0.05] showed an increasing trend; Norway, New Zealand, The Netherlands, Slovakia, France, Colombia, Lithuania, and the USA showed an increasing trend (P > 0.05). It is predicted that the mortality rate in Slovenia and France's female population will show an increasing trend by 2035. It is predicted that the absolute number of deaths in the Israeli male population and in Chile, France, and Canada female population will increase by 2035.

CONCLUSION

In the past decade, the incidence and mortality of gastric cancer have shown a decreasing trend; however, there are still some countries showing an increasing trend, especially among populations younger than 45 years. Although mortality in most countries is predicted to decline by 2035, the absolute number of deaths due to gastric cancer may further increase due to population growth.

The Effect of Nationwide Organized Cancer Screening Programs on Gastric Cancer Mortality: A Synthetic Control Study

BACKGROUND & AIMS

Nationwide organized gastric cancer (GC) screening programs have been running for decades in South Korea and Japan. This study conducted a quasi-experimental analysis to assess the population impact of these programs on GC mortality.

METHODS

We used the flexible synthetic control method (SCM) to estimate the effect of the screening programs on age-standardized GC mortality and other upper gastrointestinal (UGI) diseases (esophageal cancer and peptic ulcer) among people aged ≥40 years. World Health Organization mortality data and country-level covariates from the World Bank and the Global Burden of Diseases study were used for the analyses. We compared postintervention trends in outcome with the counterfactual trend of the synthetic control and estimated average postintervention rate ratios (RRs) with associated 95% confidence intervals (CIs). A series of sensitivity analyses were conducted.

RESULTS

The preintervention fits were acceptable for the analyses of South Korea and Japan's GC mortality but poor for Japan's other UGI disease mortality. The average postintervention RRs were 0.83 (95% CI, 0.71-0.96) for GC mortality and 0.72 (95% CI, 0.57-0.90) for other UGI disease mortality in South Korea. The RR reached 0.59 by the 15th year after the initiation of nationwide screening. For Japan, the average RRs were 0.97 (95% CI, 0.88-1.07) for GC mortality and 0.93 (95% CI, 0.68-1.28) for other UGI disease mortality. Sensitivity analysis reveals the result for Japan may potentially be biased.

CONCLUSIONS

South Korea's nationwide GC screening has apparent benefits, whereas the Japanese program's effectiveness is uncertain. The experiences of South Korea and Japan could serve as a reference for other countries.

Clinicopathologic differences of gastric neoplasms between Helicobacter pylori-infected and -naïve patients: a multicenter retrospective analysis

BACKGROUND

The incidence of gastric neoplasms in Helicobacter pylori (Hp)-naïve patients has recently increased due to a remarkable decrease in the Hp-infected population in Japan. We investigated the clinicopathologic differences between Hp-infected gastric neoplasms (HpIGNs) and Hp-naïve gastric neoplasms (HpNGNs) that have not been fully elucidated so far.

METHODS

This retrospective multicenter study investigated 966 consecutive patients with 1131 gastric dysplasia or cancers who underwent endoscopic or surgical treatment for the recent decade. Clinicopathologic features were compared between HpIGN and HpNGN cases.

RESULTS

One thousand and sixty-eight HpIGNs in 916 patients included 877 differentiated types and 191 undifferentiated types. Sixty-three HpNGNs in 50 patients included 57 differentiated types (35 foveolar types, 15 intestinal types, 6 fundic-gland types, and 1 other differentiated type) and 6 undifferentiated types. HpNGNs occurred in younger (59.5 vs. 71.8 years, p < 0.05) and female patients (40.0% vs. 26.5%, p < 0.05), were found more frequently in the proximal compartment (p < 0.05), and had smaller size (median 4.0 vs. 20.0 mm, p < 0.05). Histologically, HpNGNs and HpIGNs both primarily consisted of differentiated type (90.5% vs. 82.1%, p = 0.089) and HpNGNs showed lower prevalence of invasive cancer (11.1% vs. 37.6%, p < 0.05) and lymphovascular invasion (1.6% vs. 31.6%, p < 0.05). Nearly all HpNGNs (62/63, 98.4%) were diagnosed in early pathological stage, while 16.1% (172/1068) of HpIGNs were diagnosed in advanced stage (p < 0.05).

CONCLUSIONS

HpNGNs is recently on the increase but shows lower malignant nature regardless of histologic type than HpIGN. Endoscopic gastric cancer screening will be reviewed via cost effectiveness for Hp-naïve individuals in future.

Enhancing the Quality of Upper Gastrointestinal Endoscopy: Current Indicators and Future Trends

The quality of upper gastrointestinal endoscopy (EGD) is crucial and carries significant consequences for patient outcomes, the employment of healthcare resources, and the future course of gastroenterology as a medical specialty. In this review, we navigate through the terrain of the Quality Indicators (QIs) for EGD, shedding light on their indispensable function in ensuring and augmenting the quality of patient care throughout the pre-procedural, intra-procedural, post-procedural, and outcome-oriented facets of the practice. We delve into the comprehensive scope of the QIs and the challenges impeding the delivery of high-quality EGD, from variability in practitioner training and patient compliance to the systemic limitations of current QIs and the barriers hindering the adoption of advanced techniques. Future directions for bolstering the quality of EGD are highlighted, encapsulating the integration of emergent endoscopic technologies, the evolution of patient-centered metrics, the refinement of endoscopist training and credentialing processes, and the promise held by Artificial Intelligence (AI). Particular emphasis is placed on the role of advanced endoscopic techniques and equipment in enhancing EGD quality. This article presents a cogent narrative, promoting the pursuit of excellence in EGD as an ever-evolving endeavor that necessitates the collective dedication of clinicians, researchers, educators, and policymakers.

Biennial Endoscopic Surveillance of Gastrointestinal Metaplasia and Its Subtypes Reduces Gastric Cancer Mortality and Is Cost-Effective in a Markov State Transition Model

OBJECTIVES

Gastric cancer in the United States has a low survival rate mainly because of the late stage of diagnosis. Furthermore, there are no well-established guidelines concerning screening and surveillance even for higher risk patients such as those with nondysplastic noncardia gastrointestinal metaplasia (GIM), and thus they are not routinely performed. This study was designed to provide new evidence-based data that can be used to support the implementation of biennial surveillance guidelines in individuals with nondysplastic noncardia GIM. This practice can help detect early malignant lesions, thereby decreasing morbidity and mortality. We evaluated the cost-effectiveness of surveillance endoscopies for noncardia gastric cancer in populations with two different pathological diagnoses: mixed GIM and incomplete GIM (iGIM).

METHODS

Markov state transition models were developed using a cohort simulation of 1000 hypothetical patients. Analysis was conducted for both mixed and iGIM. Quality-adjusted life-years and transition probabilities were derived from the published medical literature. Costs associated with endoscopy, cancer care, and surgery were based on Medicare reimbursement. A willingness-to-pay threshold of $100,000 per quality-adjusted life-year was used to determine cost-effectiveness.

RESULTS

Our study determined that it is significantly cost-effective to perform biennial endoscopy surveillance in patients who have been incidentally found to have noncardia mixed GIM, with a cost savings of $5783.84 per person, and in those with iGIM, with a cost savings of $8093.08 per person.

CONCLUSIONS

Biennial endoscopy surveillance should be considered in all individuals found to have mixed or incomplete noncardia GIM on endoscopy. Furthermore, screening specifically for iGIM after differentiating between the two groups can lead to further cost savings. As such, we recommend that pathologists routinely differentiate between the two and recommend robust routine surveillance of iGIM.

Identification of serum microRNAs as potential diagnostic biomarkers for detecting precancerous lesions of gastric cancer

Aim

Gastric mucosal changes associated with chronic gastritis are known to be precancerous lesions of gastric cancer. We aimed to identify individuals with a high risk of gastric cancer by detection of microRNAs (miRNA) in the blood as biomarkers.

Methods

Of 1206 individuals screened, 144 who were positive for Helicobacter pylori (H. pylori) by the serum antibody test and who underwent endoscopy were the subjects of this study. For the gross assessment of mucosal inflammation, we applied the Kimura-Takemoto classification, in which normal mucosa was defined as grade 0, and atrophy was categorized as grade 1 (C-1 and C-2), grade 2 (C-3 and O-1), and grade 3 (O-2 and O-3). Serum samples were divided into two phases and used for miRNA microarray profiling. We compared the expression of miRNAs in grade 3 mucosa and other grades. Expression in gastric cancer was confirmed with TCGA data.

Results

miR-196b-3p was significantly upregulated, and miR-92a-2-5p was downregulated (P < .05 and q < 0.2). TCGA data showed a high expression of miR-196b-3p in gastric cancer cases (P < .001). Comparing grade 3 and the others, the area under the receiver operating characteristic curve using the detected miRNAs was as high as about 0.7. Furthermore, the combination of miRNAs resulted in higher accuracy. In terms of the significance of the combinatory mRNAs, the combination of three miRNAs (miR-196b-3p, miR-92a-2-5p, and miR-6791-3p) revealed high sensitivity and specificity, with the area under the curve exceeding 0.8.

Conclusion

The identified combinatory miRNAs may represent promising biomarkers of precancerous lesions in gastric cancer.

Forthcoming Step in Gastric Cancer Prevention: How Can Risk Stratification Be Combined with Endoscopic Screening for Gastric Cancer?

Although the concern for gastric cancer prevention has increased, gastric cancer has remained a heavy burden worldwide and is not just a local issue in East Asian countries. However, as several screening programs (listed below) have shown some success, it is important to determine whether the situation is changing in some other countries and whether similar methods should be recommended. Endoscopic screening has been performed as a national program in South Korea and Japan, and the results have shown a reduction in gastric cancer mortality. Although the efficacy of Helicobacter pylori eradication has been established, the efficacy of the screen-and-treat strategy is presently being evaluated in randomized controlled trials. The serum pepsinogen test and endoscopic examination can divide high-risk subjects with severe gastric atrophy from average-risk subjects. Risk stratification is anticipated to contribute to an efficient method of prediction of gastric cancer development when combined with endoscopic screening. Countries with a high incidence rate should realize the immediate need to reduce gastric cancer death directly by endoscopic screening and should recognize screen-and-treat as a second option to reduce future risk. However, all forms of gastric cancer prevention programs have some harms and potential to increase unnecessary examinations. A balance of the benefits and harms should be always considered. Although further study is needed to obtain sufficient evidence for gastric cancer prevention, the best available method should be examined in the context of each country.

Need for improvement in the evaluation of pre-malignant upper gastro-intestinal lesions in India: Results of a nationwide survey

BACKGROUND AND AIM

Gastric and esophageal cancers are associated with high morbidity in India. In the absence of formal screening programs in India, it is essential that all elective esophago-gastro-duodenoscopies (EGDs), irrespective of indication, be also considered an opportunity to screen for premalignant lesions. With this premise, we tried to assess the adherence to best practices in the detection of premalignant upper gastro-intestinal lesions (PMUGIL) among endoscopists in India. We also evaluated the adequacy of training, availability of appropriate facilities, and differences between teaching and non-teaching centers.

METHODS

We disbursed a survey among endoscopists working in India, through the membership database of the Society of Gastrointestinal Endoscopists of India, by email and instant messaging. The responses were collected and subsequently analyzed.

RESULTS

We obtained a total of 422 eligible responses. The adherence to best practices assessed was lower than the set threshold in all except one parameter in both teaching centers and non-teaching centers. Only 58.5% of endoscopists had received training in the detection of PMUGIL. Appropriate image enhanced endoscopy (IEE) facilities were available to only 58.05% of surveyed endoscopists.

CONCLUSIONS

Strategies to improve detection of PMUGIL should be directed at improving adherence to best practices, ensuring adequate training of endoscopists in the evaluation of PMUGIL and improving infrastructure.

Trend in Gastric Cancer Mortality in Kazakhstan

OBJECTIVE

The aim is to study the trends in gastric cancer (GC) mortality in Kazakhstan.

METHODS

Data on those who died from GC and on the annual population were obtained from the Bureau of National Statistics of the Agency for Strategic Planning and Reforms of the Republic of Kazakhstan. A retrospective study was carried out for the period 2009-2018 using descriptive and analytical methods of oncoepidemiology. The extensive, crude and age-specific mortality rates are determined according to the generally accepted methodology used in sanitary statistics.

RESULTS

GC mortality in Kazakhstan is considered to be decreasing. It was determined that during the studied period 19,672 died of this cancer. The mean of death was 67.8 with 95% CI of 67.6 to 68.0. The highest mortality rates per 100,000 in the entire population were found in the age groups 75-79 years (145.9±24.1), 80-84 years (161.0±11.0), and 85+ years (116.5±16.4). Trends in age-related mortality rates had a pronounced tendency to increase in 70-74 years (T=+4.3%, R2=0.1924) and to decrease in the age of up to 30 (T=-8.7%, R2=0.2426). The average annual standardized mortality rate was 13.2 per 100,000, and in trends   tended to decrease (T=-5.8%; R2=0.9763). In all regions, there is a decrease in mortality, except for the city of Astana. During categorization mortality rates were determined on the basis of standardized indicators: low - up to 12.9, average - from 12.9 to 15.1, high - above 15.1 per 100,000 for the entire population.

CONCLUSION

The mortality rates from GC tend to decrease, while the downward trends and the degree of their approximation are expressed in almost all regions. The study of regional mortality has theoretical and practical significance for monitoring and evaluating the effectiveness of early detection and treatment. Health authorities should take into account the results obtained when organizing antitumor measures.

Assigning a different endoscopist for each annual follow-up may contribute to improved gastric cancer detection rates

Background and study aims  Esophagogastroduodenoscopy (EGD) is an effective and important diagnostic tool to detect gastric cancer (GC). Although previous studies show that examiner, patient, and instrumental factors influence the detection of GC, we analyzed whether assigning a different examiner to surveillance EGD would improve the detection of GC compared to assigning the same examiner as in the previous endoscopy. Patients and methods  We retrospectively reviewed patients who underwent two or more consecutive surveillance EGDs at a single center between 2017 and 2019. We identified factors associated with GC detection using multivariable regression analysis and propensity-score matching. Results  Among 7794 patients, 99 GC lesions in 93 patients were detected by surveillance EGD (detection rate; 1.2 %), with a mean surveillance interval of 11.2 months. Among the detected 99 lesions, 87 (87.9 %) were curatively treated with endoscopy. There were no differences in the clinicopathologic characteristics of GC detected by the same or different endoscopists. GC detection in the group examined by different endoscopists was more statistically significant than in the group examined by the same endoscopist, even after propensity-score matching (1.6 % and 0.7 %; P  < 0.05). Endoscopic experience and other factors were not statistically significant between the two groups. Conclusions  In surveillance EGD, having a different endoscopist for each exam may improve GC detection rates, regardless of the endoscopist's experience.

An Approach to the Primary and Secondary Prevention of Gastric Cancer in the United States

BACKGROUND & AIMS

Gastric cancer (GC) remains a leading cause of mortality among certain racial, ethnic, and immigrant groups in the United States (US). The majority of GCs are diagnosed at advanced stages, and overall survival remains poor. There exist no structured national strategies for GC prevention in the US.

METHODS

On March 5-6, 2020 a summit of researchers, policy makers, public funders, and advocacy leaders was convened at Stanford University to address this critical healthcare disparity. After this summit, a writing group was formed to critically evaluate the effectiveness, potential benefits, and potential harms of methods of primary and secondary prevention through structured literature review. This article represents a consensus statement prepared by the writing group.

RESULTS

The burden of GC is highly inequitably distributed in the US and disproportionately falls on Asian, African American, Hispanic, and American Indian/Alaskan Native populations. In randomized controlled trials, strategies of Helicobacter pylori testing and treatment have been demonstrated to reduce GC-specific mortality. In well-conducted observational and ecologic studies, strategies of endoscopic screening have been associated with reduced GC-specific mortality. Notably however, all randomized controlled trial data (for primary prevention) and the majority of observational data (for secondary prevention) are derived from non-US sources.

CONCLUSIONS

There exist substantial, high-quality data supporting GC prevention derived from international studies. There is an urgent need for cancer prevention trials focused on high-risk immigrant and minority populations in the US. The authors offer recommendations on how strategies of primary and secondary prevention can be applied to the heterogeneous US population.

Gastric cancer screening: a systematic review and meta-analysis

BACKGROUND AND AIMS

Gastric cancer (GC) screening is recommended in high-risk populations, although screening methods and intervals vary. In intermediate-risk populations, screening through esophagogastroduodenoscopy (EGD) may be considered depending on local resources. The aim of this study was to compare GC screening methods regarding effect on mortality, diagnostic yield and adherence.

METHODS

Systematic review and meta-analysis including studies evaluating population-based GC screening. Search was conducted in three online databases (MEDLINE, Scopus and clinicaltrials.gov), along with manual search.

RESULTS

Forty-four studies were included. Studies in upper gastrointestinal series (UGIS) demonstrated that GC screening was associated with significantly lower GC mortality rates (OR 0.63, 95% CI 0.55 - 0.73). Benefits on mortality were also found in EGD and serum pepsinogen (PG) studies. EGD was associated with significantly higher GC (0.55%, 95% CI 0.39 - 0.75%) and early-GC (EGC) detection rates (0.48%, 95% CI 0.34 - 0.65%) when compared to UGIS (GC 0.19%, 95% CI 0.10 - 0.31%; EGC 0.08%, 95% CI 0.04 - 0.13%) and PG (GC 0.10%, 95% CI 0.05 - 0.16%; EGC 0.10%, 95% CI 0.04 - 0.19%). Non-invasive methods tended to higher adherence rates when compared to EGD. Regardless of the screening method, individualized recruitment performed better.

DISCUSSION

Screening positively impacted GC mortality rates. EGD was associated with higher diagnostic yield, while UGIS and PG tended to higher adherence rates. Screening uptake was predominantly impacted by recruitment strategies independently of the adopted method.

Global burden of gastric cancer in adolescents and young adults: estimates from GLOBOCAN 2020

OBJECTIVES

Gastric cancer in adolescents and young adults (GCAYA) has been ignored by both patients and physicians. We examined the disease burden of GCAYA and its secular trends in incidence and mortality.

STUDY DESIGN

A comprehensive analysis of the global burden of GCAYA based on data provided by GLOBOCAN 2020.

METHODS

Global, regional, sex, and country-specific data of the incidence and mortality of GCAYA were extracted from the GLOBOCAN, the Cancer in Five Continents Plus, and the World Health Organization mortality database, respectively. The associations between the Human Development Index (HDI) and GCAYA burden were also evaluated by Pearson correlation analysis.

RESULTS

The global incidence of GCAYA was 0.79 per 100,000, and the corresponding mortality was 0.45 per 100,000 in 2020. The mortality-to-incidence ratio (MIR) was lower in AYA (0.61) than in patients aged 40-64 years (0.65) and patients aged 65 years and older (0.75). The age-standardized incidence rates (ASIR) and age-standardized mortality rates (ASMR) were 0.84 and 0.53 per 100,000, respectively, in women, compared with 0.74 and 0.45 per 100,000, respectively, in men. The majority of new cases (17,934) and deaths (10,360) were estimated to occur in Asia. There has a significant negative correlation between the MIR of GCAYA and HDI level (R2 = 0.2707, P < 0.0001). There was a decreasing trend of incidence and mortality in most countries.

CONCLUSIONS

The MIR of GCAYA is lower than that among older patients and exhibit a positive association with socio-economic status. The incidence and mortality of GCAYA show a decreasing trend in most countries.

Effectiveness of endoscopic screening for gastric cancer: The Japan Public Health Center-based Prospective Study

Upper gastrointestinal endoscopy for gastric cancer screening has been implemented in Japan. However, its effectiveness for gastric cancer prevention has not been fully studied. We aimed to investigate the effectiveness of endoscopic screening to reduce mortality from gastric cancer. In a large prospective population‐based cohort study including 80,272 participants, we compared the risk of mortality and incidence of gastric cancer among participants who underwent endoscopic or radiographic screening compared with those who did not undergo any screening using multivariable Cox proportional hazards models. In the 1,023,364 person‐year observation period (median; 13.0 years), 1977 cases of gastric cancer were diagnosed, and 783 patients with gastric cancer died. In the endoscopic screening group, the mortality from gastric cancer and incidence of advanced gastric cancer were reduced by 61% (hazard ratio [HR] = 0.39 [95% CI: 0.30–0.51]) and 22% (HR = 0.78 [95% CI: 0.67–0.90]), respectively. The radiographic screening reduced the mortality from gastric cancer (HR = 0.63 [95% CI: 0.54–0.73]), but its effectiveness was lower than that of endoscopic screening. In conclusion, endoscopic screening reduced the incidence of advanced gastric cancer and mortality from gastric cancer in the Japanese population.

Gastric cancer incidence, mortality and burden in adolescents and young adults: a time-trend analysis and comparison among China, South Korea, Japan and the USA

OBJECTIVES

To evaluate and compare the burden of gastric cancer in adolescents and young adults (GCAYA) among China, South Korea, Japan and the USA, four countries with similar or different rates of gastric cancer (GC) incidence, development levels and cancer control strategies.

DESIGN

This population-based observational study collected the epidemiological data of GCAYA from the Global Burden of Diseases Study 2019. The trend magnitude and directions over time for incidence and mortality of GCAYA were analysed and compared among four countries.

MAIN OUTCOMES AND MEASURES

Outcomes included new cases, deaths, mortality-to-incidence ratios (MIRs), disability-adjusted life years, and their age-standardised rates and estimated annual percentage changes (AAPCs).

RESULTS

There were 49 008 new cases and 27 895 deaths from GCAYA in 2019, nearly half of which occurred in China. The AAPCs for the age-standardised incidence and mortality rate were 0.3 (-0.1 to 0.7), -3.6 (-3.7 to -3.4), -3.2 (-3.8 to -2.6), -0.1 (-0.6 to 0.5) and -2.0 (-2.3 to -1.6), -5.6 (-6.2 to -5.0), -4.4 (-4.7 to -4.1), -0.7 (-1.0 to -0.3) in China, South Korea, Japan and the USA, respectively. The incidence rate for females in the USA rose by 0.4% annually. GC ranks fifth, first, fourth and ninth in China, South Korea, Japan and the USA regarding burdens caused by cancer in adolescents and young adults. The MIRs declined constantly in South Korea and China, and the MIR in the USA became the highest in 2019.

CONCLUSIONS

Although not covered by prevention and screening programmes, variations in disease burden and time trends may reflect variations in risk factors, cancer control strategies and treatment accessibility of GC among the four countries. Investigating the reasons behind the varying disease burden and changing trends of GCAYA across countries will inform recommendations for prevention measures and timely diagnosis specific to this underserved population to further decrease the GC burden.

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.

Convolutional neural network-based system for endocytoscopic diagnosis of early gastric cancer

Background

Endocytoscopy (ECS) aids early gastric cancer (EGC) diagnosis by visualization of cells. However, it is difficult for non-experts to accurately diagnose EGC using ECS. In this study, we developed and evaluated a convolutional neural network (CNN)-based system for ECS-aided EGC diagnosis.

Methods

We constructed a CNN based on a residual neural network with a training dataset comprising 906 images from 61 EGC cases and 717 images from 65 noncancerous gastric mucosa (NGM) cases. To evaluate diagnostic ability, we used an independent test dataset comprising 313 images from 39 EGC cases and 235 images from 33 NGM cases. The test dataset was further evaluated by three endoscopists, and their findings were compared with CNN-based results.

Results

The trained CNN required 7.0 s to analyze the test dataset. The area under the curve of the total ECS images was 0.93. The CNN produced 18 false positives from 7 NGM lesions and 74 false negatives from 28 EGC lesions. In the per-image analysis, the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 83.2%, 76.4%, 92.3%, 93.0%, and 74.6%, respectively, with the CNN and 76.8%, 73.4%, 81.3%, 83.9%, and 69.6%, respectively, for the endoscopist-derived values. The CNN-based findings had significantly higher specificity than the findings determined by all endoscopists. In the per-lesion analysis, the accuracy, sensitivity, specificity, PPV, and NPV of the CNN-based findings were 86.1%, 82.1%, 90.9%, 91.4%, and 81.1%, respectively, and those of the results calculated by the endoscopists were 82.4%, 79.5%, 85.9%, 86.9%, and 78.0%, respectively.

Conclusions

Compared with three endoscopists, our CNN for ECS demonstrated higher specificity for EGC diagnosis. Using the CNN in ECS-based EGC diagnosis may improve the diagnostic performance of endoscopists.

Venous Invasion Is a Risk Factor for Recurrence of pT1 Gastric Cancer with Lymph Node Metastasis

BACKGROUND

Postoperative adjuvant therapy for early gastric cancer (EGC) has not been widely studied, and there are differing indications for postoperative adjuvant therapy between Western and Asian countries. Japanese gastric cancer treatment guidelines do not recommend adjuvant chemotherapy for EGC, but it is unclear whether surgery alone is the most appropriate treatment.

METHODS

This is a single-center retrospective study of 1001 consecutive patients who underwent radical gastrectomy for pT1 gastric cancer between 1999 and 2013 at the Wakayama Medical University Hospital.

RESULTS

Recurrence was observed in 12 patients, nine of whom as the result of hematogenous metastasis. In all patients with pT1 gastric cancer (n = 1001), lymph node metastasis was identified as an independent predictive factor for recurrence (hazard ratio [HR] = 10.910, P = 0.002). In patients with pT1N + gastric cancer, however, the 5-year disease-specific survival (DSS) rate was still high, 90.8%. In patients with pT1N + gastric cancer (n = 97), the presence of venous invasion (pT1N + v +) was identified by univariate and multivariate analyses as an independent risk factor for recurrence (HR = 4.791, P = 0.032). In patients with venous invasion, the 5-year DSS rate was significantly lower than that in those without venous invasion (79.3% vs. 95.2%, P = 0.018).

CONCLUSIONS

Long-term prognosis of patients with EGC with lymph node metastasis is good, but venous invasion is associated with a higher risk of recurrence. Selective application of postoperative adjuvant chemotherapy for pT1N + v + gastric cancer may efficiently improve prognosis among patients with EGC.

Development and evaluation of a double-check support system using artificial intelligence in endoscopic screening for gastric cancer

BACKGROUND

This study aimed to prevent missing gastric cancer and point out low-quality images by developing a double-check support system (DCSS) for esophagogastroduodenoscopy (EGD) still images using artificial intelligence.

METHODS

We extracted 12,977 still EGD images from 855 cases with cancer [821 with early gastric carcinoma (EGC) and 34 malignant lymphoma (ML)] and developed a lesion detection system using 10,994 images. The remaining images were used as a test dataset. Additional validation was performed using a new dataset containing 50 EGC and 1,200 non-GC images by comparing the interpretation of ten endoscopists (five trainees and five experts). Furthermore, we developed another system to detect low-quality images, which are not suitable for diagnosis, using 2198 images.

RESULTS

In the validation of 1983 images from the 124 cancer cases, the DCSS diagnosed cancer with a sensitivity of 89.2%, positive predictive value (PPV) of 93.3%, and an accuracy of 83.3%. EGC was detected in 93.2% and ML in 92.5% of cases. Comparing with the endoscopists, sensitivity was significantly higher in the DCSS, and the average diagnostic time was significantly shorter using the DCSS than that by the trainees. The sensitivity, specificity, PPV, and accuracy in detecting low-quality images were 65.8%, 93.1%, 79.6%, and 85.2% for "Blur" and 57.8%, 91.7%, 82.2%, and 78.1% for "Mucus adhesion," respectively.

CONCLUSIONS

The DCSS showed excellent capability in detecting lesions and pointing out low-quality images.

Identification of Combinations of Plasma lncRNAs and mRNAs as Potential Biomarkers for Precursor Lesions and Early Gastric Cancer

Patients with gastric cancer (GC) are usually first diagnosed at an advanced stage due to the absence of obvious symptoms at an early GC (EGC) stage. Therefore, it is necessary to identify an effective screening method to detect precursor lesions of GC (PLGC) and EGC to increase the 5-year survival rate of patients. Cell-free RNA, as a biomarker, has shown potential in early diagnosis, personalised treatment, and prognosis of cancer. In this study, six RNAs (CEBPA-AS1, INHBA-AS1, AK001058, UCA1, PPBP, and RGS18) were analysed via real-time quantitative polymerase chain reaction (RT-qPCR) using the plasma of patients with EGC and PLGC to identify diagnostic biomarkers. The receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic accuracy. Among the six RNAs, four lncRNAs (CEBPA-AS1, INHBA-AS1, AK001058, and UCA1) were upregulated and two mRNAs (PPBP and RGS18) were downregulated in the plasma of patients with PLGC and EGC. According to the findings of the ROC analysis, the four-RNA combination of INHBA-AS1, AK001058, UCA1, and RGS18 had the highest area under the curve (AUC) value for determining risk of GC in patients with PLGC and the six-RNA combination including CEBPA-AS1, INHBA-AS1, AK001058, UCA1, PPBP, and RGS18 had the highest AUC value for determining the risk of GC in patients with EGC. The results suggest the potential usefulness of noninvasive biomarkers for the molecular diagnosis of GC at earlier stages.

Recent Estimates and Predictions of 5-Year Survival in Patients with Gastric Cancer: A Model-Based Period Analysis

BACKGROUND

The overall incidence and mortality of gastric cancer have steadily declined in the United States over the past few decades, but it is still a serious disease burden for patients. Therefore, it is of great significance to evaluate the latest survival rate of gastric cancer.

METHODS

Based on the Surveillance, Epidemiology, and End Results database, this study analyzed the age-standardized relative survival rates and survival trends of gastric cancer cases in 2007-2011 and 2012-2016 using period analysis, and the survival rate 2017-2021 was predicted using a generalized linear model based on the period analysis.

RESULTS

During 2007-2016, the 5-year relative survival rate of patients with gastric cancer continued to rise, and the same trend was observed in 2017-2021. The 5-year overall age-standardized relative survival rates in 2007-2011, 2012-2016, and 2017-2021 were 38.3%, 40.6%, and 42.9%, respectively. However, despite these favorable trends, the overall relative survival of patients with gastric cancer remains at a low level. There were significant differences in the relative survival rates of patients with gastric cancer in terms of age, sex, race, primary site, stage, and socioeconomic status. Notably, the survival rate of patients with distant-stage gastric cancer remains very low (10%).

CONCLUSION

We found that the survival rate of patients with gastric cancer showed different degrees of improvement in each subgroup. However, the overall relative survival rate of patients with gastric cancer remains low. Analyzing the changes of patients with gastric cancer in the last 10 years will be helpful in predicting the changing trend of cancer in the future. It also provides a scientific basis for relevant departments to formulate effective tumor prevention and control measures.

Endoscopic Screening and Surveillance for Gastric Cancer

Gastric cancer is one of the most common cancers worldwide. Gastric cancer is a multifactorial disease, and the incidence varies widely by geographic region, with half of new cases occurring in East Asia. Population-based nationwide screening for gastric cancer has been implemented in some Eastern Asian countries such as South Korea and Japan. In these countries, endoscopic screening decreased gastric cancer mortality. Endoscopic screening seems to be a cost-effective modality in countries with high incidence of gastric cancer. However, the usefulness of population-based screening has not yet been proved in countries with low incidence of gastric cancer.

Lessons learned from upper gastrointestinal endoscopy in asymptomatic Chinese

BACKGROUND

The Helicobacter pylori (H. pylori) infection-related diseases, peptic ulcer, and gastric cancer are frequently asymptomatic until the onset of complications. This study aimed to investigate the prevalence of H. pylori, erosive esophagitis, peptic ulcer, and precancerous lesions such as atrophic gastritis, intestinal metaplasia, gastric dysplasia, and upper gastrointestinal (GI) malignancy in asymptomatic Chinese.

METHODS

From January to December 2017, a questionnaire was administered to consecutive asymptomatic patients undergoing routine physical examination, which included their first screening esophagogastroduodenoscopy. H. pylori infection was determined by one of positive ¹³ C urea breath tests or rapid urease test and histology. The presence of H. pylori infection, erosive esophagitis, peptic ulcer, precancerous gastric histology, and upper GI malignancy was analyzed in relation to demographic factors.

RESULTS

A total of 1108 subjects (mean age: 48, range 21 to 79, 39.5% men) were included. The findings were: erosive esophagitis 7.8%, active H. pylori infection 44%, peptic ulcer 9.1% (duodenal 5.8%, gastric 2.5% or both 0.8%); 0.5% had gastric cancer. Male, smoking history, and current H. pylori infection were all significantly related to the presence of peptic ulcer. Totally, 1095 patients had gastric histopathology and premalignant gastric lesions were present in 67.4%; atrophic gastritis (67.4%), intestinal metaplasia (27.4%), and gastric dysplasia (0.5%). Age, current and previous H. pylori infection were risk factors significantly associated with precancerous lesions.

CONCLUSIONS

Upper GI pathology as a sequelae of H. pylori infection is common in asymptomatic Chinese. These findings support institution of a nationwide test and treat program to eradicate H. pylori in China.

Feasibility of Endoscopic Screening for Upper Gastrointestinal Malignancy in a Comprehensive Health Checkup

Objective In an effort to reduce mortality from gastric cancer, endoscopic screening was introduced in 2016 as a nationwide screening program in Japan. Recent developments in high-definition endoscopic imaging and diagnostic strategies have enabled the simultaneous detection of other upper gastrointestinal (U-GI) malignancies. Therefore, we conducted a study to evaluate the feasibility of endoscopic screening for U-GI malignancy in a comprehensive health checkup. Methods We retrospectively reviewed the data of 13,120 participants who had received a comprehensive health checkup in a single institution between April 2012 and March 2018. Participants were divided into two groups [gastrointestinal endoscopy (GIE) group (n=9,142) and gastrointestinal X-ray (X-ray) group (n=3,978)] and compared with regards to the screening results, adverse events, and detection rate of U-GI malignancies (gastric cancer or other) using a propensity-score matched analysis. Results The gastric cancer detection rate was significantly higher in the GIE group [34/9,142 (0.48%)] than in the X-ray group [3/3,978 (0.08%)] (p=0.003). Other U-GI malignancies were found only in the GIE group and comprised two hypopharyngeal cancers, five esophageal cancers, two duodenal cancers, and one duodenal gastrointestinal stromal tumor. Adverse events occurred in 6/9,142 (0.07%) participants in the GIE group and 18/3,978 (0.45%) participants in the X-ray group (p<0.0001). A propensity-score matched analysis yielded 1,551 matched pairs, and the detection rate of gastric cancer and other U-GI malignancies remained significantly higher in the GIE group than in the X-ray group. Conclusion This study indicated that not only gastric cancer but also other U-GI malignancies can be detected by endoscopic screening.

Effectiveness of one-time endoscopic screening programme in prevention of upper gastrointestinal cancer in China: a multicentre population-based cohort study

OBJECTIVES

To estimate the effectiveness of endoscopic screening programme in reducing incidence and mortality of upper gastrointestinal cancer in high risks areas of China.

DESIGN

This multicentre population-based cohort study was conducted in six areas in China from 2005 to 2015. All permanent residents aged 40 to 69 years were identified as target subjects. We refer to those who were invited for screening collectively as the invited group. Of these, we classify those who were invited and undertook endoscopic screening as the screened group and those who were invited but did not accept screening as the non-screened group. Target subjects who were not invited to the screening were assigned to the control group. The effectiveness of the endoscopic screening and screening programme were evaluated by comparing reductions in incidence and mortality from upper gastrointestinal cancer in the screened and invited group with control group.

RESULTS

Our cohort analysis included 637 500 people: 299 483 in the control group and 338 017 in the invited to screening group, 113 340 (33.53%) of whom were screened eventually. Compared with subjects in the control group, upper gastrointestinal cancer incidence and mortality decreased by 23% (relative risk (RR)=0.77, 95% CI 0.74 to 0.81) and 57% (RR=0.43, 95% CI 0.40 to 0.47) in the screened group, respectively, and by 14% (RR=0.86, 95% CI 0.84 to 0.89) and 31% (RR=0.69, 95% CI 0.66 to 0.72) in the invited group, respectively.

CONCLUSION

Among individuals aged 40 to 69 years in high risk areas of upper gastrointestinal cancer, one-time endoscopic screening programme was associated with a significant decrease in upper gastrointestinal cancer incidence and mortality.

Feasibility of Plasma-Methylated SFRP2 for Early Detection of Gastric Cancer

Gastric cancer (GC) is fifth most frequently diagnosed cancer and second leading cause of cancer in China. More than 80% of GC are diagnosed at an advanced stage due to low uptake rate of invasive screening method. The performance of methylated SFRP2 test was evaluated in 236 plasma samples, including 92 patients with GC, 16 intestinal metaplasia patients, 26 gastric fundic gland polyp patients, 13 small adenoma patients, 39 hyperplastic polyp patients, and 50 control patients. The sensitivity of plasma methylated SFRP2 was compared to serum CEA, CA72-4, CA19-9, and CA242 results in 79 patients with GC. The sensitivities for detecting GC and gastric intestinal metaplasia by methylated SFRP2 test were 60.9% and 56.3% with a specificity of 86.0%. Methylated SFRP2 test had significantly higher positive detection rate for patients with GC than gastric fundic gland polyp, small adenoma, and hyperplastic polyp patients. In 79 patients with GC, the sensitivities of CEA, CA72-4, CA19-9, and CA242 for detecting GC were 22.8%, 16.5%, 12.7%, and 11.4%. In comparison, the sensitivity of methylated SFRP2 test for detecting GC was 58.2%. Plasma methylated SFRP2 test may become a valuable tool for the noninvasive detection of GC and precursor lesions and showed higher sensitivity than serum tumor markers.

Utility of Kyoto Classification of Gastritis in subjects with a high-negative titer of anti-Helicobacter pylori antibody during a medical check-up

Subjects with a high-negative titer (3-9.9 U/ml) of serum anti-Helicobacter pylori (H. pylori) antibody represent a heterogeneous group of currently H. pylori-infected, H. pylori-uninfected, and previously H. pylori-infected cases. We investigated the characteristics of subjects with a high-negative titer during a medical check-up and the utility of H. pylori infection score, the sum of scores of endoscopic findings based on the Kyoto Classification of Gastritis, for diagnosing H. pylori infection. Subjects with ¹³C-urea breath test-positive or H. pylori stool antigen test-positive were diagnosed as currently H. pylori-infected. Although around half of subjects with a high-negative titer were after eradication therapy (48.6%), currently H. pylori-infected were considerably confirmed (11.7%). H. pylori infection score showed a high value of area under the receiver operating characteristic curve [0.92; 95% confidence interval (CI), 0.84-1.00] with the most suitable cut-off value of 1.0 (sensitivity: 0.92; specificity: 0.90). Multivariate logistic regression analysis revealed that H. pylori infection score was an independent factor associated with increased prevalence of H. pylori infection (odds ratio, 9.53; 95% CI, 2.64-34.40; p<0.001). Currently H. pylori-infected subjects were considerably included among the subjects with a high-negative titer, and the Kyoto Classification of Gastritis was useful to predict current H. pylori infection.

Frontiers of Robotic Gastroscopy: A Comprehensive Review of Robotic Gastroscopes and Technologies

Simple Summary

With the rapid advancements of medical technologies and patients’ higher expectations for precision diagnostic and surgical outcomes, gastroscopy has been increasingly adopted for the detection and treatment of pathologies in the upper digestive tract. Correspondingly, robotic gastroscopes with advanced functionalities, e.g., disposable, dextrous and not invasive solutions, have been developed in the last years. This article extensively reviews these novel devices and describes their functionalities and performance. In addition, the implementation of artificial intelligence technology into robotic gastroscopes, combined with remote telehealth endoscopy services, are discussed. The aim of this paper is to provide a clear and comprehensive view of contemporary robotic gastroscopes and ancillary technologies to support medical practitioners in their future clinical practice but also to inspire and drive new engineering developments.

Abstract

Upper gastrointestinal (UGI) tract pathology is common worldwide. With recent advancements in robotics, innovative diagnostic and treatment devices have been developed and several translational attempts made. This review paper aims to provide a highly pictorial critical review of robotic gastroscopes, so that clinicians and researchers can obtain a swift and comprehensive overview of key technologies and challenges. Therefore, the paper presents robotic gastroscopes, either commercial or at a progressed technology readiness level. Among them, we show tethered and wireless gastroscopes, as well as devices aimed for UGI surgery. The technological features of these instruments, as well as their clinical adoption and performance, are described and compared. Although the existing endoscopic devices have thus far provided substantial improvements in the effectiveness of diagnosis and treatment, there are certain aspects that represent unwavering predicaments of the current gastroenterology practice. A detailed list includes difficulties and risks, such as transmission of communicable diseases (e.g., COVID-19) due to the doctor–patient proximity, unchanged learning curves, variable detection rates, procedure-related adverse events, endoscopists’ and nurses’ burnouts, limited human and/or material resources, and patients’ preferences to choose non-invasive options that further interfere with the successful implementation and adoption of routine screening. The combination of robotics and artificial intelligence, as well as remote telehealth endoscopy services, are also discussed, as viable solutions to improve existing platforms for diagnosis and treatment are emerging.

Guidelines for endoscopic diagnosis of early gastric cancer

The Japan Gastroenterological Endoscopy Society developed the Guideline for Endoscopic Diagnosis of Early Gastric Cancer based on scientific methods. Endoscopy for the diagnosis of early gastric cancer has been acknowledged as a useful and highly precise examination, and its use has become increasingly more common in recent years. However, the level of evidence in this field is low, and it is often necessary to determine recommendations based on expert consensus only. This clinical practice guideline consists of the following sections to provide the current guideline: [I] Risk stratification of gastric cancer before endoscopic examination, [II] Detection of early gastric cancer, [III] Qualitative diagnosis of early gastric cancer, [IV] Diagnosis to choose the therapeutic strategy for gastric cancer, [V] Risk stratification after endoscopic examination, and [VI] Surveillance of early gastric cancer.

Present status and perspective of chemotherapy for patients with unresectable advanced or metastatic gastric cancer in Japan

Patients with unresectable advanced or recurrent gastric cancer have a poor prognosis with overall survival times increasing by only a few months after anti-cancer drug therapy in the last four decades. The survival times from previous clinical trials for untreated metastatic gastric cancer in Japan are generally better than those reported from trials in European and North or South American countries. Therefore, the proportion of Japanese patients enrolled in recent global trials of novel anti-cancer drugs should be increased in order to identify drugs that specifically prolong the survival of such patients. S-1 plus oxaliplatin (SOX) therapy is the most commonly used standard first-line treatment for advanced gastric cancer in Japan. SOX induces mild nausea and vomiting, even in elderly patients, that can be treated by maintaining oral intake with adequate anti-emetic treatment usually given in an outpatient clinic. Neutropenia, nausea, and vomiting in SOX therapy were more frequently observed in female patients compared with males. Intensive toxic chemotherapy such as triplet therapy never prolonged overall survival or maintained a favorable quality of life. The current strategies used against metastatic gastric cancer need to be modified in regard to innovative treatments with current drugs, keeping in mind each categorized treatment population. In a real world of a diverse society even if the same treatment is performed, the outcome of the individual patient is different. It is important for each society to implement established treatment, knowing that the evidence from global trials aimed at drug approval does not necessarily show external validity.

Utilizing Cultural and Ethnic Variables in Screening Models to Identify Individuals at High Risk for Gastric Cancer: A Pilot Study

Identifying persons at high risk for gastric cancer is needed for targeted interventions for prevention and control in low-incidence regions. Combining ethnic/cultural factors with conventional gastric cancer risk factors may enhance identification of high-risk persons. Data from a prior case-control study (40 gastric cancer cases and 100 controls) were used. A "conventional model" using risk factors included in the Harvard Cancer Risk Index's gastric cancer module was compared with a "parsimonious model" created from the most predictive variables of the conventional model as well as ethnic/cultural and socioeconomic variables. Model probability cutoffs aimed to identify a cohort with at least 10 times the baseline risk using Bayes' Theorem applied to baseline U.S. gastric cancer incidence. The parsimonious model included age, U.S. generation, race, cultural food at ages 15-18 years, excessive salt, education, alcohol, and family history. This 11-item model enriched the baseline risk by 10-fold, at the 0.5 probability level cutoff, with an estimated sensitivity of 72% [95% confidence interval (CI), 64-80], specificity of 94% (95% CI, 90-97), and ability to identify a subcohort with gastric cancer prevalence of 128.5 per 100,000. The conventional model was only able to reach a risk level of 9.8 times baseline with a corresponding sensitivity of 31% (95% CI, 23-39) and specificity of 97% (95% CI, 94-99). Cultural and ethnic data may add important information to models for identifying U.S. individuals at high risk for gastric cancer, who then could be targeted for interventions to prevent and control gastric cancer. The findings of this pilot study remain to be validated in an external dataset.

Quality Indicators for the Detection of Helicobacter pylori-Negative Early Gastric Cancer: A Retrospective Observational Study

Background/Aims

While Helicobacter pylori (HP)-negative gastric cancer is frequently reported, little is known about the predictors for detecting HP-negative early gastric cancer (EGC). We aimed to evaluate the predictors for the detection of HP-negative EGC.

Methods

We retrospectively reviewed 13,477 consecutive asymptomatic cases where upper endoscopy was performed by nine physicians from April 2017 to March 2019 and analyzed the detection rate of high-risk lesions (HRLs), including EGC, tubular adenoma, and lymphoma, according to the status of HP infection. The observation time was corrected for multiple regression analyses.

Results

For all physicians, the average observation time for screening HP-eradicated and -naïve patients was shorter than that for screening HP-positive patients (p<0.05). Multiple regression analyses revealed that the observation time in the three groups was an independent predictor for detecting HRLs in HP-eradicated patients (p=0.03106, 0.01263, and 0.02485, respectively), while experience of endoscopy was an independent predictor for detecting HRLs in HP-naïve patients (p=0.02638).

Conclusions

While observation time during screening endoscopy was a quality indicator for detecting HRLs in HP-eradicated patients, experience of endoscopy was a quality indicator for detecting HRLs in HP-naïve patients.

Low baseline awareness of gastric cancer risk factors amongst at-risk multiracial/ethnic populations in New York City: results of a targeted, culturally sensitive pilot gastric cancer community outreach program

Background and Aims: There are limited efforts to address modifiable risk factors for gastric cancer (GC) among racial/ethnic groups at higher GC risk, which may reflect decreased public awareness of risk factors. Our primary aim was to assess baseline awareness of GC risk factors and attitudes/potential barriers for uptake of a GC screening program among high-risk individuals.Methods: Participants attended a linguistically and culturally targeted GC educational program in East Harlem (EH)/Bronx and Chinatown communities in New York City. Demographic information and relevant behavioral/lifestyle habits were collected. Participants' ability to identify GC risk factors and attitudes/barriers surrounding GC screening were assessed before and after the program.Results: Of the 168 included participants, most were female with 77% above age 70. Nearly half of participants in the EH/Bronx programs identified themselves as black and 63% as Hispanic/Latino; 93% of the Chinatown participants identified as Chinese. Among EH/Bronx participants, the majority correctly identified older age, smoking, alcohol, H. pylori, family history, race/ethnicity, excess salt, and preserved foods as risk factors. Among Chinatown participants, the majority correctly identified smoking, alcohol, race/ethnicity, and excess salt, although only 53% and 57.8% correctly identified H. pylori and preserved foods, respectively; the majority incorrectly answered that older age was not a major risk factor. The majority in both groups failed to identify male gender as higher risk and incorrectly identified stress and obesity as major risk factors. Participants were more concerned about the potential findings on GC screening tests than the risks and costs or having to take time off work.Conclusion: Among multiracial/ethnic groups of individuals presumably at higher risk for GC, we identified several gaps in baseline knowledge of both modifiable and non-modifiable GC risk factors. Culturally and linguistically appropriate educational interventions may be a worthwhile adjunctive intervention within the context of a targeted GC screening program.

The long-term population impact of endoscopic screening programmes on disease burdens of gastric cancer in China: A mathematical modelling study

BACKGROUND

Gastric cancer (GC) incidence and mortality in China remained high due to delayed diagnosis and accounted for about half of the world's GC cases and deaths. Early detection with endoscopic screening and consequent timely treatment can significantly improve survival. This study aimed to explore the long-term population impact of endoscopic screening on national GC disease burdens in China.

METHODS

Most of previous studies investigated the disease burdens of cancer using Markov model or age-period-cohort (APC) model, which are difficult to estimate the population size of undiagnosed cases. In this paper, we proposed a new dynamic compartmental model based on GC natural history and calibrated model outputs to diagnosed GC cases and GC-related death counts using Markov Chain Monte Carlo methods. We investigated the impact of screening strategies with various coverage (10%, 40%, 70%) and frequency (every 1, 3, 5 years) on disease burdens.

RESULTS

We estimated that 2.22 (95%CI: 1.97-2.47) million Chinese are living with GC in 2019, among which, 42.7% (40.3-45.0%) remained undiagnosed. Without systematic screening, we projected 10.46 (9.07-11.86) million incident cases and 7.35 (6.59-8.11) million GC-related deaths over the next 30 years (2019-2049). Screening with coverage rate at 10%, 40%, 70% every 3 years could prevent 0.85 (0.63-1.06), 2.32 (1.79-2.86), and 3.04 (2.38-3.70) million incident cases, and prevent 1.17 (1.01-1.32), 3.08 (2.70-3.46), and 3.93 (3.46-4.40) million deaths respectively, compared with 'no screening' scenario. Screening would substantially increase the number of diagnosed GC cases within the first three years of program initiation, but this number would quickly reduce below 'no screening' scenario. Three-yearly screening at the above coverage rates would reduce the proportion of undiagnosed GC cases to 38.8% (36.9-40.7%), 25.5% (23.4-27.6%), and 17.8% (16.0-19.6%) by 2049, respectively. Delaying implementation of the screening program would substantially reduce its effectiveness.

CONCLUSIONS

Initiating national endoscopic screening programmes would likely have a major effect on reducing GC incidence and mortality in China. Health resources should be substantially increased and directed to treatment of GC to cope with the initial rise in diagnosed GC cases.

British Society of Gastroenterology guidelines on the diagnosis and management of patients at risk of gastric adenocarcinoma

Gastric adenocarcinoma carries a poor prognosis, in part due to the late stage of diagnosis. Risk factors include Helicobacter pylori infection, family history of gastric cancer-in particular, hereditary diffuse gastric cancer and pernicious anaemia. The stages in the progression to cancer include chronic gastritis, gastric atrophy (GA), gastric intestinal metaplasia (GIM) and dysplasia. The key to early detection of cancer and improved survival is to non-invasively identify those at risk before endoscopy. However, although biomarkers may help in the detection of patients with chronic atrophic gastritis, there is insufficient evidence to support their use for population screening. High-quality endoscopy with full mucosal visualisation is an important part of improving early detection. Image-enhanced endoscopy combined with biopsy sampling for histopathology is the best approach to detect and accurately risk-stratify GA and GIM. Biopsies following the Sydney protocol from the antrum, incisura, lesser and greater curvature allow both diagnostic confirmation and risk stratification for progression to cancer. Ideally biopsies should be directed to areas of GA or GIM visualised by high-quality endoscopy. There is insufficient evidence to support screening in a low-risk population (undergoing routine diagnostic oesophagogastroduodenoscopy) such as the UK, but endoscopic surveillance every 3 years should be offered to patients with extensive GA or GIM. Endoscopic mucosal resection or endoscopic submucosal dissection of visible gastric dysplasia and early cancer has been shown to be efficacious with a high success rate and low rate of recurrence, providing that specific quality criteria are met.

Artificial intelligence and upper gastrointestinal endoscopy: Current status and future perspective

With recent breakthroughs in artificial intelligence, computer-aided diagnosis (CAD) for upper gastrointestinal endoscopy is gaining increasing attention. Main research focuses in this field include automated identification of dysplasia in Barrett's esophagus and detection of early gastric cancers. By helping endoscopists avoid missing and mischaracterizing neoplastic change in both the esophagus and the stomach, these technologies potentially contribute to solving current limitations of gastroscopy. Currently, optical diagnosis of early-stage dysplasia related to Barrett's esophagus can be precisely achieved only by endoscopists proficient in advanced endoscopic imaging, and the false-negative rate for detecting gastric cancer is approximately 10%. Ideally, these novel technologies should work during real-time gastroscopy to provide on-site decision support for endoscopists regardless of their skill; however, previous studies of these topics remain ex vivo and experimental in design. Therefore, the feasibility, effectiveness, and safety of CAD for upper gastrointestinal endoscopy in clinical practice remain unknown, although a considerable number of pilot studies have been conducted by both engineers and medical doctors with excellent results. This review summarizes current publications relating to CAD for upper gastrointestinal endoscopy from the perspective of endoscopists and aims to indicate what is required for future research and implementation in clinical practice.

Docetaxel plus cisplatin and S-1 versus cisplatin and S-1 in patients with advanced gastric cancer (JCOG1013): an open-label, phase 3, randomised controlled trial

BACKGROUND

We investigated the superiority of docetaxel plus cisplatin and S-1 compared with cisplatin and S-1 in chemotherapy-naive patients with advanced gastric cancer.

METHODS

In this open-label, phase 3, randomised controlled trial, patients were recruited from 56 hospitals in Japan. We enrolled individuals aged 20-75 years who had unresectable or recurrent gastric cancer, had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, had received no previous chemotherapy (except adjuvant chemotherapy completed 24 weeks before reccurence), radiotherapy, or hormonal therapy, could take drugs orally, and had adequate organ function. Patients were randomly assigned (1:1) to receive docetaxel plus cisplatin and S-1 (docetaxel 40 mg/m² and cisplatin 60 mg/m² on day 1 intravenously, and S-1 40-60 mg twice a day orally for 2 weeks, every 4 weeks) or cisplatin and S-1 (cisplatin 60 mg/m² intravenously on day 8, and S-1 40-60 mg orally twice a day for 3 weeks, every 5 weeks). Randomisation was done centrally with the minimisation method, with a random component balancing for institution, ECOG performance status (0 vs 1), disease status at enrolment (unresectable vs recurrent), measurable lesion (yes vs no), number of metastatic sites (0-1 vs ≥2), and histological type (differentiated vs undifferentiated). Neither investigators or patients were masked to the study treatment. The primary endpoint was overall survival in the intention-to-treat population. The study is registered with UMIN-CTR, number UMIN000007652.

FINDINGS

Between April 3, 2012, and March 18, 2016, 741 patients were randomly assigned to receive docetaxel plus cisplatin and S-1 (n=370) or cisplatin and S-1 (n=371). Median overall survival was 14·2 months (95% CI 12·9-15·9) in the docetaxel plus cisplatin and S-1 group and 15·3 months (14·2-16·2) in the cisplatin and S-1 group (hazard ratio [HR] 0·99 [95% CI 0·85-1·16]; one-sided stratified log-rank p=0·47). The most common grade 3 or worse adverse events were neutropenia (209 [59%] of 357 patients in the docetaxel plus cisplatin and S-1 group vs 117 [32%] of 365 patients in the cisplatin and S-1 group), leukopenia (120 [34%] vs 60 [16%]), and anorexia (94 [26%] vs 81 [22%]). The deaths of one patient in the cisplatin and S-1 group and in three patients in the docetaxel plus cisplatin and S-1 group were deemed treatment-related.

INTERPRETATION

The addition of docetaxel to cisplatin and S-1 did not improve overall survival in chemotherapy-naive Japanese patients with advanced gastric cancer. Therefore, cisplatin and S-1 remains the standard first-line chemotherapy.

FUNDING

Ministry of Health, Labour and Welfare and Japan Agency for Medical Research and Development.

Upper Endoscopy up to 3 Years Prior to a Diagnosis of Gastric Cancer Is Associated With Lower Stage of Disease in a USA Multiethnic Urban Population, a Retrospective Study

OBJECTIVES

In the USA, certain races and ethnicities have a disproportionately higher gastric cancer burden. Selective screening might allow for earlier detection and curative resection. Among a USA-based multiracial and ethnic cohort diagnosed with non-cardia gastric cancer (NCGC), we aimed to identify factors associated with curable stage disease at diagnosis.

METHODS

We retrospectively identified endoscopically diagnosed and histologically confirmed cases of NCGC at Mount Sinai Hospital in New York City. Demographic, clinical, endoscopic and histologic factors, as well as grade/stage of NCGC at diagnosis were documented. The primary outcome was the frequency of curable-stage NCGC (stage 0-1a) at diagnosis in patients with versus without an endoscopy negative for malignancy prior to their index exam diagnosing NCGC. Additional factors associated with curable-stage disease at diagnosis were determined.

RESULTS

A total of 103 racially and ethnically diverse patients were included. Nearly 38% of NCGC were stage 0-Ia, 34% stage Ib-III, and 20.3% stage IV at diagnosis. A significantly higher frequency of NCGC was diagnosed in curable stages among patients who had undergone an endoscopy that was negative for malignancy prior to their index endoscopy that diagnosed NCGC, compared to patients without a negative endoscopy prior to their index exam (69.6% vs. 28.6%, p=0.003). A prior negative endoscopy was associated with 94.0% higher likelihood of diagnosing curable-stage NCGC (p=0.003). No other factors analyzed were associated with curable-stage NCGC at diagnosis.

CONCLUSIONS

Endoscopic screening and surveillance in select high-risk populations might increase diagnoses of curable-stage NCGC. These findings warrant confirmation in larger, prospective studies.

Utility of a standardized training program for endoscopic diagnosis of early gastrointestinal neoplasia

Background and study aims  Image enhanced endoscopy (IEE) allows endoscopists to improve recognition and characterization of gastrointestinal neoplasia. The Asian Novel Bio-Imaging and Intervention Group (ANBIG) conducted a standardized training program in endoscopic diagnosis and treatment of early gastrointestinal cancers in Asia. We embarked on a study to investigate the effect of this module on endoscopic diagnosis of early gastrointestinal neoplasia. Methods  This prospectively collected database was from workshops conducted on training for endoscopic diagnosis of early gastrointestinal neoplasia. All workshops were conducted in a standardized format, which included a pretest, a learning phase consisting of didactic lectures, case discussion, and live demonstration followed by a post-test to assess knowledge gained. The pretest and post-training tests were standardized questions addressing four domains, including basic knowledge of imaging and diagnosis of esophageal, gastric, and colonic neoplasia. Results  From November 2013 to November 2016, 41 ANBIG workshops were conducted in 13 countries. A total of 1863 delegates and 40 faculty participated in these workshops. Of the delegates, 627 completed both tests. There was a significant improvement after training in all domains of the tests. There was a trend in general lack of knowledge across all domains for delegates from "low" healthcare cost countries before training. All delegates demonstrated significant improvement in knowledge of all domains after the workshop irrespective of whether they were from "high" or "low" healthcare cost per capita countries. Conclusion  A standardized teaching program on IEE improved the diagnostic ability and quality of endoscopists in recognizing early gastrointestinal neoplasia in Asia.

Extended Gastrectomy for T4b Gastric Adenocarcinoma: Single-Surgeon Experience

PURPOSE

This study reports single-surgeon experience with extended gastrectomy including en-bloc resection of adjacent organs/structures for T4b stage gastric adenocarcinoma. Time-related changes in patient selection criteria and outcomes were also analyzed.

METHODS

All consecutive gastrectomies for adenocarcinoma performed between May 2004 and December 2017 were extracted from prospectively collected database to study surgical and oncologic results. Time-related changes in outcomes were examined according to three time periods.

RESULTS

Five hundred eighty-seven gastrectomies were performed throughout the study period including 87 (14.8%) extended resections. The latter most often included pancreatosplenectomy, colon, and liver resections (21, 16, and 11 patients, respectively) resulting in similar postoperative outcomes and survival. Extended gastrectomy was associated with larger tumor size (8.4 vs 5.6 cm), performing total gastrectomy (55.2 vs 35.2%, p < 0.01) and increased blood loss (375 vs 150 ml, p < 0.01) compared with standard gastrectomy. Larger experience in extended gastrectomy allowed for expanding patient selection criteria, considering complex resections and extensive lymphadenectomy. Median and 3-year survival following extended gastrectomy for T4b adenocarcinoma were 14 months and 18%, respectively, which was comparable to standard gastrectomy for T4a adenocarcinoma (p = 0.48). Obesity, nodal stage and type of gastrectomy were associated with survival in T4b adenocarcinoma in the univariable analysis. Obesity and N3a and N3b stages were independent predictors in the multivariable model.

CONCLUSIONS

Extended gastrectomy for T4b gastric adenocarcinoma provides satisfactory surgical outcomes even with expanded patient selection criteria and regardless of the organ involved. Given its poor prognosis, neoadjuvant therapy should be considered to improve the long-term oncologic results.

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.

Cost Effectiveness of Gastric Cancer Screening According to Race and Ethnicity

BACKGROUND & AIMS

There are marked racial and ethnic differences in non-cardia gastric cancer prevalence within the United States. Although gastric cancer screening is recommended in some regions of high prevalence, screening is not routinely performed in the United States. Our objective was to determine whether selected non-cardia gastric cancer screening for high-risk races and ethnicities within the United States is cost effective.

METHODS

We developed a decision analytic Markov model with the base case of a 50-year-old person of non-Hispanic white, non-Hispanic black, Hispanic, or Asian race or ethnicity. The cost effectiveness of a no-screening strategy (current standard) for non-cardia gastric cancer was compared with that of 2 endoscopic screening modalities initiated at the time of screening colonoscopy for colorectal cancer: upper esophagogastroduodenoscopy with biopsy examinations and continued surveillance only if intestinal metaplasia or more severe pathology is identified or esophagogastroduodenoscopy with biopsy examinations continued every 2 years even in the absence of identified pathology. We used prevalence rates, transition probabilities, costs, and quality-adjusted life years (QALYs) from publications and public data sources. Outcome measures were reported in incremental cost-effectiveness ratios, with a willingness-to-pay threshold of $100,000/QALY.

RESULTS

Compared with biennial and no screening, screening esophagogastroduodenoscopy with continued surveillance only when indicated was cost effective for non-Hispanic blacks ($80,278/QALY), Hispanics ($76,070/QALY), and Asians ($71,451/QALY), but not for non-Hispanic whites ($122,428/QALY). The model was sensitive to intestinal metaplasia prevalence, transition rates from intestinal metaplasia to dysplasia to local and regional cancer, cost of endoscopy, and cost of resection (endoscopic or surgical).

CONCLUSIONS

Based on a decision analytic Markov model, endoscopic non-cardia gastric cancer screening for high-risk races and ethnicities could be cost effective in the United States.

Endoscopic Screening in Asian Countries Is Associated With Reduced Gastric Cancer Mortality: A Meta-analysis and Systematic Review

BACKGROUND & AIMS

It is not clear how endoscopic screening for gastric cancer affects incidence or mortality. We performed a systematic review and meta-analysis to evaluate the relationship between endoscopic screening for gastric cancer and mortality and incidence.

METHODS

We conducted a systematic search of PubMed and EMBASE for published cohort and case-control studies of adults without gastric cancer who underwent endoscopic screening at least once that included a comparator and reported outcomes of mortality or incidence through March 8, 2018. Two investigators independently reviewed the included studies and extracted relevant data. The effect estimate of interest was the relative risk (RR). We used a random effects model to combine RRs and 95% confidence intervals (Cis).

RESULTS

Our final analysis included 6 cohort studies and 4 nested case-control studies comprising 342,013 individuals, all from Asia. The combined result (RR, 0.60; 95% CI, 0.49-0.73) indicated that endoscopic screening was associated with a 40% RR reduction in gastric cancer mortality. We did not observe an association between endoscopic screening and incidence (RR, 1.14; 95% CI, 0.93-1.40). Subgroup analysis showed significant reductions in gastric cancer mortality after endoscopic screening compared with no screening (RR, 0.58; 95% CI, 0.48-0.70) or radiographic screening (RR, 0.33; 95% CI, 0.12-0.91). However, endoscopic screening did not significantly reduce mortality compared with expected deaths (RR, 0.67; 95% CI, 0.38-1.16).

CONCLUSIONS

In a systematic review and meta-analysis, we found that endoscopic screening may reduce the risk of death from gastric cancer and not affect incidence in Asian countries. Population-based prospective cohort studies are warranted to confirm our findings.