Gastric Cancer Screening Program Research Articles

Performance of the National Cancer Screening Program for Gastric Cancer in Korea

In Korea, the National Cancer Screening Program for Gastric Cancer (NCSP-GC) was implemented in 1999 to reduce the mortality associated with gastric cancer, the most common cancer in Korea until 2018. In 2021, approximately 7.76 million screening endoscopies were performed as part of the NCSP-GC, including 10664 participants (37.2% of the total gastric cancer cases in 2021; 10909 of the 29361 cases) with histologically confirmed gastric cancer, according to data from the Korean National Health Insurance Service. The endoscopic screening component of the NCSP-GC has contributed to the early detection of gastric cancer and the reduction of its mortality. This review evaluates the performance and limitations of the endoscopic screening component of the NCSP-GC and discusses strategies to overcome limitations.

Risk Prediction Models for Gastric Cancer: A Scoping Review.

Gastric cancer is a significant contributor to the global cancer burden. Risk prediction models aim to estimate future risk based on current and past information, and can be utilized for risk stratification in population screening programs for gastric cancer. This review aims to explore the research design of existing models, as well as the methods, variables, and performance of model construction. Six databases were searched through to November 4, 2023 to identify appropriate studies. PRISMA extension for scoping reviews and the Arksey and O'Malley framework were followed. Data sources included PubMed, Embase, Web of Science, CNKI, Wanfang, and VIP, focusing on gastric cancer risk prediction model studies. A total of 29 articles met the inclusion criteria, from which 28 original risk prediction models were identified that met the analysis criteria. The risk prediction model is screened, and the data extracted includes research characteristics, prediction variables selection, model construction methods and evaluation indicators. The area under the curve (AUC) of the models ranged from 0.560 to 0.989, while the C-statistics varied between 0.684 and 0.940. The number of predictor variables is mainly concentrated between 5 to 11. The top 5 most frequently included variables were age, helicobacter pylori (Hp), precancerous lesion, pepsinogen (PG), sex, and smoking. Age and Hp were the most consistently included variables. This review enhances understanding of current gastric cancer risk prediction research and its future directions. The findings provide a strong scientific basis and technical support for developing more accurate gastric cancer risk models. We expect that these conclusions will point the way for future research and clinical practice in this area to assist in the early prevention and treatment of gastric cancer.

A feasibility study on utilizing machine learning technology to reduce the costs of gastric cancer screening in Taizhou, China.

To optimize gastric cancer screening score and reduce screening costs using machine learning models. This study included 228,634 patients from the Taizhou Gastric Cancer Screening Program. We used three machine learning models to optimize Li's gastric cancer screening score: Gradient Boosting Machine (GBM), Distributed Random Forest (DRF), and Deep Learning (DL). The performance of the binary classification models was evaluated using the area under the curve (AUC) and area under the precision-recall curve (AUCPR). In the binary classification model used to distinguish low-risk and moderate- to high-risk patients, the AUC in the GBM, DRF, and DL full models were 0.9994, 0.9982, and 0.9974, respectively, and the AUCPR was 0.9982, 0.9949, and 0.9918, respectively. Excluding Helicobacter pylori IgG antibody, pepsinogen I, and pepsinogen II, the AUC in the GBM, DRF, and DL models were 0.9932, 0.9879, and 0.9900, respectively, and the AUCPR was 0.9835, 0.9716, and 0.9752, respectively. Remodel after removing variables IgG, PGI, PGII, and G-17, the AUC in GBM, DRF, and DL was 0.8524, 0.8482, 0.8477, and AUCPR was 0.6068, 0.6008, and 0.5890, respectively. When constructing a tri-classification model, we discovered that none of the three machine learning models could effectively distinguish between patients at intermediate and high risk for gastric cancer (F1 scores in the GBM model for the low, medium and high risk: 0.9750, 0.9193, 0.5334, respectively; F1 scores in the DRF model for low, medium, and high risks: 0.9888, 0.9479, 0.6694, respectively; F1 scores in the DL model for low, medium, and high risks: 0.9812, 0.9216, 0.6394, respectively). We concluded that gastric cancer screening indicators could be optimized when distinguishing low-risk and moderate to high-risk populations, and detecting gastrin-17 alone can achieve a good discriminative effect, thus saving huge expenditures.

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

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. 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. 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. 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.

Development and validation of LightGBM algorithm for optimizing of Helicobacter pylori antibody during the minimum living guarantee crowd based gastric cancer screening program in Taizhou, China

Gastric cancer continues to be a significant health concern in China, with a high incidence rate. To mitigate its impact, early detection and treatment is key. However, conducting large-scale endoscopic gastric cancer screening is not feasible in China. Instead, a more appropriate approach would be to initially screen high-risk groups and follow up with endoscopic testing as needed. We conducted a study on 25,622 asymptomatic participants aged 45–70 years from a free gastric cancer screening program in the Taizhou city government's Minimum Living Guarantee Crowd (MLGC) initiative. Participants completed questionnaires, blood tests, and underwent gastrin-17 (G-17), pepsinogen I and II (PGI and PGII), and H. pylori IgG antibody (IgG) assessments. Using the light gradient boosting machine (lightGBM) algorithm, we developed a predictive model for gastric cancer risk. In the full model, F1 score was 2.66%, precision was 1.36%, and recall was 58.14%. In the high-risk model, F1 score was 2.51%, precision was 1.27%, and recall was 94.55%. Excluding IgG, the F1 score was 2.73%, precision was 1.40%, and recall was 68.62%. We conclude that H. pylori IgG appears to be able to be excluded from the prediction model without significantly affecting its performance, which is important from a health economic point of view. It suggests that screening indicators can be optimized, and expenditures reduced. These findings can have important implications for policymakers, as we can focus resources on other important aspects of gastric cancer prevention and control.

Endoscopic evaluation by the Kyoto classification of gastritis combined with serum anti-Helicobacter pylori antibody testing reliably risk-stratifies subjects in a population-based gastric cancer screening program.

We previously demonstrated that the Kyoto classification of gastritis was useful for judging the status of Helicobacter pylori infection in a population-based screening program, and that adding H. pylori antibody test improved its accuracy (UMIN000028629). Here, we tested whether our endoscopic diagnosis of H. pylori infection status reliably estimated gastric cancer risk in the program. Data were collected from1345 subjects who underwent endoscopic follow-up 4years after the end of the registration. We analyzed the association of three diagnostic methods of H. pylori infection with gastric cancer detection: (1) endoscopic diagnosis based on the Kyoto classification of gastritis; (2) serum diagnosis according to the ABC method (H. pylori antibody and pepsinogen I and II); and (3) endoscopic diagnosis together with H. pylori antibody test. During the follow-up, 19 cases of gastric cancer were detected. By Kaplan-Meier analysis, the detection rates of cancer were significantly higher in the past or current H. pylori infection groups than in the never-infected group with all 3 methods. By the Cox proportional hazards model, the hazard ratio for cancer detection was highest in evaluation with the combined endoscopic diagnosis and the antibody test (method 3; hazard ratio 22.6, 95% confidence interval 2.99-171) among the three methods (the endoscopic diagnosis (method 1); 11.3, 2.58-49.8, and the ABC method (method 2); 7.52, 2.49-22.7). Endoscopic evaluation of H. pylori status with the Kyoto classification of gastritis, especially combined with serum anti-Helicobacter pylori antibody testing, reliably risk-stratified subjects in a population-based gastric cancer screening program.

Disparities and outcomes in young adults admitted for gastric cancer in the US.

298 Background: Although global incidence of gastric cancer has been decreasing over the past decades, an upward trend has been reported in younger patients and certain ethnic groups over the past few years. The reason for this epidemiological trend is not fully understood, but differences in presentation and prognosis suggest that gastric cancer in the young might represent a different clinical entity. Here, we seek to identify differences in demographic characteristics and outcomes between young adults and older patients admitted for gastric cancer. Methods: Using the National Inpatient Sample (NIS) database, we identified all adult patients admitted primarily for gastric cancer from 2016 to 2019. We analyzed demographic characteristics of young adults (defined as those aged between 20 and 49-years-old) and older patients (aged 50 and above) as well as differences in in-hospital mortality, total hospital charges, and length of stay. Multivariate logistic regression analysis was conducted to adjust for confounders. Results: During the period studied, 77,720 patients were admitted with gastric cancer, of which 9,650 (12.4%) were young adults and 68,115 (87.6%) were old individuals. Young adults were more likely to be female (42.4 vs. 35.6%, p < 0.01). Hispanics comprised 30.9% of admissions for gastric cancer of young adults (vs. 15% in older adults p-value <0.01). Young adults were also over 3 times more likely to be uninsured than older individuals (9.6 vs. 2.6%, p-value <0.01) and more likely to be cared for in urban (98.2 vs. 96.2%, p < 0.01) and teaching (85.4 vs. 80.8%, p < 0.01) hospitals. Young adults had longer lengths of stay and lower hospital charges (see table). No difference was found in mortality, despite a lower comorbidity burden in young adults based on the Charlson Comorbidity Index, possibly due to young adults being candidates for more aggressive therapy and having more aggressive disease. Conclusions: The higher incidence of gastric cancer in Hispanic and uninsured young adults poses a complex public health issue, especially in the context of recent research suggesting more aggressive disease in this population. The reported findings likely reflect both a shift in the U.S. population over the years as well as a rising incidence among Hispanic young adults. It is important to increase awareness of these epidemiological disparities. Further research is needed to determine whether establishing screening programs for gastric cancer in certain populations might be beneficial in the U.S. [Table: see text]

Next-Generation Sequencing Analysis of Gastric Cancer Identifies the Leukemia Inhibitory Factor Receptor as a Driving Factor in Gastric Cancer Progression and as a Predictor of Poor Prognosis.

Gastric cancer (GC) is the third cause of cancer-related mortality worldwide. Nevertheless, because GC screening programs are not cost-effective, most patients receive diagnosis in the advanced stages, when surgical options are limited. Peritoneal dissemination occurs in approximately one-third of patients with GC at the diagnosis and is a strong predictor of poor outcome. Despite the clinical relevance, biological and molecular mechanisms underlying the development of peritoneal metastasis in GC remain poorly defined. Here, we report results of a high-throughput sequencing of transcriptome expression in paired samples of non-neoplastic and neoplastic gastric samples from 31 patients with GC with or without peritoneal carcinomatosis. The RNA-seq analysis led to the discovery of a group of highly upregulated or downregulated genes, including the leukemia inhibitory factor receptor (LIFR) and one cut domain family member 2 (ONECUT2) that were differentially modulated in patients with peritoneal disease in comparison with patients without peritoneal involvement. Both LIFR and ONECUT2 predicted survival at univariate statistical analysis. LIFR and its major ligand LIF belong to the interleukin-6 (IL-6) cytokine family and have a central role in immune system regulation, carcinogenesis, and dissemination in several human cancers. To confirm the mechanistic role of the LIF/LIFR pathway in promoting GC progression, GC cell lines were challenged in vitro with LIF and a LIFR inhibitor. Among several GC cell lines, MKN45 cells displayed the higher expression of the receptor, and their exposure to LIF promotes a concentration-dependent proliferation and epithelial–mesenchymal transition (EMT), as shown by modulation of relative expression of E-cadherin/vimentin along with JAK and STAT3 phosphorylation and acquisition of a migratory phenotype. Furthermore, exposure to LIF promoted the adhesion of MKN45 cells to the peritoneum in an ex vivo assay. These effects were reversed by the pharmacological blockade of LIFR signaling. Together, these data suggest that LIFR might have a major role in promoting disease progression and peritoneal dissemination in patients with GC and that development of LIF/LIFR inhibitors might have a role in the treatment of GC.

Current status of the gastric cancer screening program in Korea

Background: In 2019, gastric cancer was one of the most common cancers in Korea. As a secondary prevention strategy for gastric cancer, the cancer screening has been provided since 1999 by the National Cancer Screening Program every 2 years for adults aged ≥40 years.Current Concepts: The participation rates for gastric cancer screening program have increased from 7.4% in 2002 to 62.9% in 2019. Until 2017, either upper gastrointestinal series or endoscopy were recommended for screening method. Since 2018, endoscopy has become the preferred screening method and 89.1% of the participants underwent endoscopy in 2019. After the introduction of the screening program, the 5-year relative survival rates have markedly improved (43.9% between 1993 and 1995 vs. 77.5% between 2015 and 2019), and the proportion of early gastric cancer detection has increased (28.6% in 1995 vs. 63.6% in 2019). The risk of death from gastric cancer decreased by 47% in participants who had undergone endoscopy screening. Additionally, the gastric cancer screening program is cost-effective, and endoscopy-associated adverse events rarely occur.Discussion and Conclusion: With the implementation of the screening program, mortality due to gastric cancer has decreased owing to early detection. After the completion of ongoing clinical trials in the general population, the primary prevention strategy of Helicobacter pylori eradication should be considered to effectively reduce the incidence of gastric cancer. Further studies are also required to provide optimal screening interval according to the presence of risk factors including H. pylori infection and presence of gastric mucosal atrophy.

Current Evidence for a Paradigm Shift in Gastric Cancer Prevention From Endoscopic Screening to Helicobacter pylori Eradication in Korea.

Gastric cancer is prevalent in Korea and ranked as the third most common cancer in 2019, followed by lung and thyroid cancers. The National Cancer Screening Program (NCSP) for gastric cancer has been implemented in adults aged ≥40 since 1999 and involves endoscopic screening every 2 years. The beneficial effects of the current NCSP on early cancer detection, cost-effectiveness, and mortality reduction are evident. However, the screening program results in a large socioeconomic burden and the consumption of medical resources, as it focuses solely on secondary prevention (early detection) rather than primary prevention of cancer. Helicobacter pylori is defined as a group I carcinogen by the International Agency for Research on Cancer. Hence, its eradication has been suggested as an important primary gastric cancer prevention strategy. Well-designed randomized controlled trials involving high-risk groups (post-endoscopic resection of early gastric cancer and family history of gastric cancer) and long-term follow-up studies in the general population have provided high-quality evidence regarding the effects of H. pylori eradication on gastric cancer prevention. In this review, we discussed the evidences for a possible modification of the current gastric cancer secondary prevention strategy by introducing primary prevention through H. pylori eradication. Areas for future research to optimize primary prevention strategies were also suggested.

A case of foveolar-type gastric adenocarcinoma with a raspberry-like appearance discovered during the Saitama City endoscopic gastric cancer screening program

A case of foveolar-type gastric adenocarcinoma with a raspberry-like appearance discovered during the Saitama City endoscopic gastric cancer screening program

Trends in the Performance of the Korean National Cancer Screening Program for Gastric Cancer from 2007 to 2016.

PurposeThe Korean National Cancer Screening Program (KNCSP) has implemented two screening methods for gastric cancer— upper gastrointestinal series (UGIS) and endoscopy—for Koreans aged ≥ 40 years. We aimed to assess performance trends for both screening methods.Materials and MethodsThe KNCSP database was used to evaluate individuals who underwent screening from 2007 to 2016. The final gastric cancer diagnosis was ascertained by linking with the Korean Central Cancer Registry. We conducted a prospective, cross-sectional analysis to estimate performance indicators of gastric cancer screening by UGIS and endoscopy, stratified by sociodemographic factors.ResultsWe found that screening rates for gastric cancer increased from 28% to 51.7% between 2007 and 2016, and that the rate of endoscopy use for gastric cancer screening increased sharply. Cancer detection rates (CDR) of UGIS and endoscopy were 0.41 and 2.25 per 1,000 screens in 2007–2008 and 0.26 and 1.99 in 2015–2016, respectively. Interval cancer rates (ICR) per 1,000 negative screenings were 1.33 (2007–2008) and 1.21 (2015–2016) for UGIS and 1.14 (2007–2008) and 0.88 (2015–2016) for endoscopy. The sensitivity of UGIS decreased from 23.6% (2007–2008) to 17.6% (2015–2016), whereas that of endoscopy increased from 66.4% (2007–2008) to 69.3% (2015–2016). Specificity was maintained at > 99% for both methods over the study period.ConclusionThe use of endoscopy for gastric cancer screening within the KNCSP has increased. Endoscopy has higher CDR, sensitivity, and specificity, and lower ICR estimates than does UGIS.

Feasibility of endoscopic evaluation of Helicobacter pylori infection status by using the Kyoto classification of gastritis in the population-based gastric cancer screening program: A prospective cohort study.

Background and aimsWe have started a new population‐based endoscopic gastric cancer screening program in Kurashiki city with consideration of Helicobacter pylori infection status based on endoscopic features. We aimed to verify the feasibility of this attempt in a prospective case‐registration study (UMIN000028629).MethodsData were collected from 1784 subjects without past eradication of H. pylori and who underwent endoscopic gastric cancer screening in Kurashiki Central Hospital Preventive Healthcare Plaza from September 2017 to June 2018. Endoscopic judgment of H. pylori infection status was made according to the Kyoto classification of gastritis. For comparison, a combination serum test of anti‐H. pylori antibody and pepsinogen I and II, the ABC method, was used.ResultsThe endoscopic diagnoses were nongastritis, 1215 (68.1%); active or inactive gastritis, 469 (26.3%); and undefined, 23 (1.3%). With the ABC method as a reference standard, the false‐negative rate of the endoscopic judgment for H. pylori infection was 16.3% (95% confidence interval: 13.1%‐20.0%). Most false‐negative cases were of Group B in the ABC method, which is considered gastritis with mild mucosal atrophy. Antibody titers in this population were mostly in the weak‐positive range but clinically significant elevation of the antibody suggesting current infection was observed in some cases.ConclusionsEndoscopic diagnosis of H. pylori infection status in a population‐based gastric cancer screening program is mostly reliable, but false‐negative results may occur, especially in patients with mild gastric atrophy. To avoid this limitation, we recommend adding H. pylori antibody test to the program.

Gastric Cancer screening – does it exist or not? - literature review

INTRODUCTION AND PURPOSE: Gastric cancer (GC) is one of the biggest healthcare problem in the world. Despite the fact that the incidence of this cancer has decreased recently, GC is on the fifth place of causes of morbidity and on the second place of causes of mortality. Therefore, some countries such as Japan and South Korea have decided to establish and develop screening methods to detect GC as early as it is possible and to begin early treatment. DESCRIPTION OT THE STAGE OF KNOWLEDGE: There are many types of screening methods such as: markers of atrophy- serum-pepsinogen test and low serum gastrin-17 concentration, barium photofluorography of mucosa or endoscopy. Upper gastrointestinal endoscopy has the highest detection rate in high-incidence areas, compared to other screening methods, because upper endoscopy makes it possible to highlight changes such as flat and non-ulcerative lesions, which are usually invisible in barium examination. An alternative to screening is the massive eradication of Helicobacter pylori. Occasionally some countries recommend genetic testing and prophylactic gastrectomy. CONCLUSIONS: Despite the high incidence of GC in Asian countries, there is still a lack of data on the cost-effectiveness of mass screening for GC. The main factor influencing the profitability of screening tests for GC is the cost of upper gastrointestinal endoscopy. Moreover, the value and usefulness of the GC screening program remains controversial in many countries.

Systematic Endoscopic Approach for Diagnosing Gastric Subepithelial Tumors.

Subepithelial tumors (SETs) are commonly encountered during upper gastrointestinal endoscopy, especially during national gastric cancer screening programs in Korea. Although the majority of SETs are benign, endoscopists harbor concerns regarding whether a SET is benign or malignant because the diagnosis cannot be established on the basis of routine endoscopic biopsy findings. The differential diagnosis of SETs is important, beginning with meticulous endoscopic examination, including the evaluation of the location, macroscopic shape, color, surface characteristics, mobility, consistency, and size of the tumors. The yield of endoscopic biopsy increases with the use of the bite-on-bite technique for SETs without the rolling or tenting sign, with large openings, and with erosion or ulceration. In this review, a systematic approach for the diagnosis of gastric SETs during conventional endoscopy is introduced.

The national trend of the gastric cancer burden in Iran from 1990 to 2017.

Gastric cancer (GC), the leading cause of cancer mortality, is the third most common cancer in Iran. To our knowledge, there have been few accurate estimates on the burden of GC in Iran. Therefore, as part of the Global Burden of Diseases Study 2017 (GBD 2017), we aimed to study and illustrate the burden of GC and to compare rates by sex and age groups at the national level in Iran from 1990 to 2017. We extracted data related to the 1990-2017 period from the GBD study. To report the burden of GC, we used disability adjusted life years (DALYs), mortality, incidence, and prevalence rates in different sex and age groups in Iran during the 1990-2017 period. Decomposition analysis was also performed to evaluate the roots change in incident cases. At a national level, the age-standardized prevalence rate (ASPR), age-standardized incidence rate (ASIR), age-standardized mortality rate (ASMR), and age-standardized DALYs rate (ASDR) in 2017 were 22.9 (95% uncertainty interval [UI]: 22.1-23.9), 14.6 (14.1-15.2), 14.9 (14.4-15.4), and 296.8 (286.3-308.7) per 100,000 population, respectively. Over the 1990-2017 period, the average annual percent changes in all of the studied age-standardized rates were negative. Moreover, the male to female sex ratios of all estimates were greater than one. The incidence rate, prevalence rate, and mortality rate slowly began to increase at the age of 50 and reached its highest level among people aged 80 years and over. The GC age-standardized rates revealed a downward trend from 1990 to 2017. The current study provides comprehensive knowledge about the GC burden in Iran. Therefore, it can help the appropriate allocation of resources for GC to expand preventive programs by reducing exposure to risk factors and Helicobacter pylori infection and by recommending increased consumption of fruits and vegetables. Also, expanding GC screening programs with laboratory tests or endoscopy can be an important step towards the reduction of the GC burden.

Screening for gastric cancer in China: Advances, challenges and visions.

Gastric cancer (GC) is one of the major cancers in China and all over the world. Most GCs are diagnosed at an advanced stage with unfavorable prognosis. Along with some other countries, China has developed the government-funded national screening programs for GC and other major cancers. GC screening has been shown to effectively decrease the incidence of and mortality from GC in countries adopting nationwide screening programs (Japan and Korea) and in studies based on selected Chinese populations. The screening of GC relies mostly on gastroendoscopy, the accuracy, reliability and safety of which have been indicated by previous studies. However, considering its invasive screening approach, requirements on skilled endoscopists and pathologists, and a high cost, developing noninvasive methods to amend endoscopic screening would be highly needed. Numerous studies have examined biomarkers for GC screening and the combination of biomarkers involving pepsinogen, gastrin, and Helicobacter pylori antibodies has been proposed for risk stratification, seeking to narrow down the high-risk populations for further endoscopy. Despite all the achievements of endoscopic screening, evidence on appropriate screening age, intervals for repeated screening, novel biomarkers promoting precision prevention, and health economics need to be accumulated to inform policymakers on endoscopic screening in China. With the guide of Health China 2030 Planning Outline, we have golden opportunities to promote prevention and control of GC. In this review, we summarize the characteristics of screening programs in China and other East Asian countries and introduce the past and current approaches and strategies for GC screening, aiming for featuring the latest advances and key challenges, and illustrating future visions of GC screening.

Effect and cost-effectiveness of national gastric cancer screening in Japan: a microsimulation modeling study

BackgroundA national endoscopic screening program for gastric cancer was rolled out in Japan in 2015. We used a microsimulation model to estimate the cost-effectiveness of current screening guidelines and alternative screening strategies in Japan.MethodsWe developed a microsimulation model that simulated a virtual population corresponding to the Japanese population in risk factor profile and life expectancy. We evaluated 15 endoscopic screening scenarios with various starting ages, stopping ages, and screening intervals. The primary outcomes were quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratio. Cost-effective screening strategies were determined using a willingness-to-pay threshold of $50,000 per QALY gained. One-way sensitivity and probabilistic sensitivity analyses were done to explore model uncertainty.ResultsUsing the threshold of $50,000 per QALY, a triennial screening program for individuals aged 50 to 75 years was the cost-effective strategy, with an incremental cost-effectiveness ratio of $45,665. Compared with no endoscopic screening, this strategy is predicted to prevent 63% of gastric cancer mortality and confer 27.2 QALYs gained per 1000 individuals over a lifetime period. Current screening guidelines were not on the cost-effectiveness efficient frontier. The results were robust on one-way sensitivity analyses and probabilistic sensitivity analysis.ConclusionsThis modeling study suggests that the endoscopic screening program in Japan would be cost-effective when implemented between age 50 and 75 years, with the screening repeated every 3 years. These findings underscore the need for further evaluation of the current gastric cancer screening recommendations.

Screening as a method of early effective diagnostics of gastric cancer

One of the most common forms of malignant neoplasms in the world for more than a decade is gastric cancer. It ranks 2nd in the structure of overall cancer and tends to grow steadily. According to the latest data, the WHO registers 750-850 thousand new cases of gastric cancer every year and more than 600 thousand people die from this disease [1]. Almost the only preventive method today, aimed at early detection of tumors is cancer screening. Its use helps to reduce mortality rate from certain types of malignant neoplasms including gastric cancer. Reasonability to perform screening of the population for malignant neoplasms in Ukraine today remains a matter of debate due to lack of awareness of the population and doctors, lack of clear understanding of the concept and process of screening, complexity and relatively high cost of screening methods, insufficient convincing evidence of its need for certain nosology of malignant tumors [3]. But at the same time, there is an urgent need inUkraine to introduce a gastric cancer screening program to determine its type, as well as to substantiate its reasonability.

Abstract PR03: Disaggregation of gastric cancer risk Between Asian American subgroups

Abstract Introduction: Within the United States (US), Asian/Pacific Islanders (APIs) are at increased risk for non-cardia gastric adenocarcinoma (NCGA) compared to non-Hispanic whites (NHWs). Previous epidemiologic research has treated APIs as an aggregated group for analysis; however, substantial genetic and environmental differences may exist within subgroups. Very limited data exist regarding gastric cancer epidemiology as stratified by API subgroup. Methods: All incident cases of NCGA diagnosed in the years 2000-2014 were identified from the Surveillance, Epidemiology, and End Results Program registries incorporating California, Connecticut, Detroit, Hawaii, Iowa, New Mexico, Seattle, Atlanta, and New Jersey. API subgroup of patients was identified: Korean, Japanese, Chinese, Vietnamese, Filipino, and Indian. API subgroup population estimates were obtained from the American Community Survey. The age-adjusted incidence rates per 100,000 population and 95% confidence intervals (CIs) were generated for each subgroup, and among non-Hispanic whites (NHWs) for reference. The stages of diagnosis (as defined by National Cancer Institute summary stage) were compared between subgroups. Differences between subgroups in all-cause mortality following diagnosis were evaluated utilizing proportional hazards (PH) regression, adjusting for differences in tumor stage, age, and gender. Results: There exist substantial differences in age-adjusted incidences of NCGA between subgroups: Koreans (34.8 per 100K), Japanese (17.0 per 100K), Vietnamese (14.6 per 100K), Chinese (11.2 per 100K), Indian (5.4 per 100K), and Filipino (5.3 per 100K). The incidence among NHWs was 3.8 per 100K. All API subgroups as well as NHWs demonstrated a decrease in age-standardized incidence over the study period. There exist differences in the proportion of cancers diagnosed at local stage: Koreans (37.8%), Japanese (28.1%), Chinese (25.7%), Vietnamese (24.4%), Indian (21.6%), Filipino (18.9%), and NHWs (23.7%). API subgroups had better overall survival from NCGA compared to NHWs (reference) in PH regression: Korean (HR 0.50, CI 0.47-0.54, p<0.001), Japanese (HR 0.79, CI 0.74-0.85, p<0.001), Vietnamese (HR 0.79, CI 0.72-0.87, p<0.001), Chinese (HR 0.70, CI 0.65-0.74, p<0.001), and Indian (HR 0.69, CI 0.58-0.81, p<0.001). These differences remained significant even after adjustment for stage of diagnosis, age, and gender. Discussion: Substantial heterogeneity in risk for NCGA exist between API subgroups. Korean Americans are at highest risk, with incidence nearly seven-fold higher than Filipinos and Indians (whose risk is similar to NHW). This suggests that the higher NCGA-risk in APIs in aggregate are driven by certain subgroups. Interestingly, Koreans, Japanese, Vietnamese, Chinese, and Indians all had better survival following NCGA diagnosis than NHWs, even after adjustment for stage of diagnosis. These epidemiologic data may hold important implications for gastric cancer screening or surveillance programs. This abstract is also being presented as Poster B104. Citation Format: Robert J. Huang, Joo Ha Hwang, Ann Hsing, Latha Palaniappan. Disaggregation of gastric cancer risk Between Asian American subgroups [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr PR03.