Gastric radiography is an important tool for early detection of cancer. During gastric radiography, the stomach is monitored using barium and effervescent granules. However, stomach compression and physiological phenomena during the examination can cause air to escape the stomach. When the stomach contracts, physicians cannot accurately observe its condition, which may result in missed lesions. Notably, no research using artificial intelligence (AI) has explored the use of gastric radiography to estimate the amount of air in the stomach. Therefore, this study aimed to develop an AI system to estimate the amount of air inside the stomach using gastric radiographs. In this observational, cross-sectional study, we collected data from 300 cases who underwent medical screening and estimated the images with poor stomach air volume. We used pre-trained models of vision transformer (ViT) and convolutional neural network (CNN). Instead of retraining, dimensionality reduction was performed on the output features using principal component analysis, and LightGBM performed discriminative processing. The combination of ViT and CNN resulted in the highest accuracy (F-value 0.792, accuracy 0.943, sensitivity 0.738, specificity 0.978). High accuracy was maintained in the prone position, where air inside the stomach could be easily released. Combining ViT and CNN from gastric radiographs accurately identified cases of poor stomach air volume. The system was highly accurate in the prone position and proved clinically useful. The developed AI can be used to provide high-quality images to physicians and to prevent missed lesions.

X-ray gastric cancer (GC) screening has been shown to decrease mortality. Population-based X-ray GC screening has been performed in Hiroshima Prefecture, Japan, since 1983 but time trends and the efficacy of the method over 39 years have not been assessed.

To evaluate time trends and efficacy of population-based X-ray GC screening and identify challenges and suggested solutions for the future.

This was a population-based retrospective study. The data were derived from aggregated data of the Hiroshima Regional Health Medical Promotion Organization, including the number and rate of participants and those requiring esophagogastroduodenoscopies (EGDs), the number and rate of participants diagnosed as having GC, and the positive predictive value of the abnormal findings detected by X-ray and confirmed by EGDs. The number and rate of esophageal cancers were also collected. Further, the cost of detecting one GC was evaluated.

The number of participants has decreased during the last four decades, from 39925 in 1983 to 12923 in 2021. The rate of those requiring EGDs decreased significantly in recent years (P < 0.001). The number of participants diagnosed as having GC has also declined, from 76 to 10 cases. However, the rate of cases diagnosed as GC among the participants remained around 0.1%. The positive predictive value increased significantly in recent years except during 1983-1991. The number and rate of accidentally detected esophageal cancers have risen recently, from 0% in 2008 to 0.02% in 2021, one-fifth of the diagnosis rate of GC. One GC diagnosis costs approximately 4200000 Japanese Yen (30000 United States Dollars) for the X-ray screenings and EGDs.

X-ray GC screening in Hiroshima has been efficient, but one challenge is the cost. Esophageal cancers may also need to be considered because they have gradually increased in recent years.

Previous systematic reviews naïvely combined biased effects of screening radiography or endoscopy observed in studies with various designs. We aimed to synthesize currently available comparative data on gastric cancer mortality in healthy, asymptomatic adults by explicitly classifying the screening effects through study designs and types of intervention effects.

We searched multiple databases through October 31, 2022 for this systematic review and meta-analysis. Studies of any design that compared gastric cancer mortality among radiographic or endoscopic screening and no screening in a community-dwelling adult population were included. The method included a duplicate assessment of eligibility, double extraction of summary data, and validity assessment using the Risk Of Bias In Non-randomized Studies of Interventions tool. Bayesian three-level hierarchical random-effects meta-analysis synthesized data corrected for self-selection bias on the relative risk (RR) for per-protocol (PP) and intention-to-screen (ITS) effects. The study registration number at PROSPERO is CRD42021277126.

We included seven studies in which a screening program was newly introduced (median attendance rate, 31%; at moderate-to-critical risk of bias), and seven cohort and eight case-control studies with ongoing screening programs (median attendance rate, 21%; all at critical risk of bias); thus, data of 1,667,117 subjects were included. For the PP effect, the average risk reduction was significant for endoscopy (RR 0.52; 95% credible interval: 0.39-0.79) but nonsignificant for radiography (0.80; 0.60-1.06). The ITS effect was not significant for both radiography (0.98; 0.86-1.09) and endoscopy (0.94; 0.71-1.28). The magnitude of the effects depended on the assumptions for the self-selection bias correction. Restricting the scope to East Asian studies only did not change the results.

In limited-quality observational evidence from high-prevalence regions, screening reduced gastric cancer mortality; however, the effects diminished at a program level.

National Cancer Center Japan; and Japan Agency for Medical Research and Development.

Gastric cancer (GC) is a leading cause of global mortality but also a cancer whose footprint is highly unequal. This review aims to define global disease epidemiology, critically appraise strategies of prevention and disease attenuation, and assess how these strategies could be applied to improve outcomes from GC in a world of variable risk and disease burden. Strategies of primary prevention focus on improving the detection and eradication of the main environmental risk factor, Helicobacter pylori. In certain countries of high incidence, endoscopic or radiographic screening of the asymptomatic general population has been adopted as a means of secondary prevention. By contrast, identification and targeted surveillance of individuals with precancerous lesions (such as intestinal metaplasia) is being increasingly embraced in nations of low incidence. This review also highlights existing knowledge gaps in GC prevention as well as the role of emerging technologies for early detection and risk stratification.