Introduction

The TOGAS consortium (TOwards GAstric cancer Screening) was established to explore effective gastric cancer screening strategies within Europe. One key method involves the detection and eradication of Helicobacter pylori (H. pylori), the leading causative agent of gastric cancer. In Western Europe, infection rates are higher among males, smokers, and individuals of lower socioeconomic status—groups that tend to engage less with preventive health services.

Aims & Methods

This pilot study aimed to determine whether targeted screening in high-risk occupational settings improves participation and outcomes compared to population-based screening via general practice.
Key outcome measures included;

1. Response rate
2. Prevalence of the infection
3. Treatment effectiveness

This prospective pilot study recruited individuals aged 30–34 years from January 2024 to March 2025. Participants were invited either through general practices (general population group, GP) or through two occupational screening programs (targeted group, TG) representing higher-risk, male-dominated workforces: the Irish Defence Forces and Construction Workers Health Trust. Exclusion criteria included prior H. pylori treatment or gastrectomy. All participants underwent serologic screening (BIOHIT H. pylori IgG antibody). The TG was offered initial on-site screening at their workplace; the GP group attended a local hospital. All seropositive individuals were offered confirmatory 13-C urea breath testing (Richen IR Force 200) in a local hospital. Confirmed cases were offered a 10-day regimen of PYLERA (Metronidazole/Tetracycline/Bismuth subcitrate) with Esomeprazole 40 mg BD. Eradication was assessed ≥6 weeks post-treatment. Response rates, demographics, infection prevalence, and treatment outcomes were analyzed using Mann-Whitney U and Chi² tests (significance p < 0.05).

Results

3030 individuals were invited for screening: 2824 in the GP group(GPG), 206 in the TG. Key demographics and risk factors of each group are shown in Table 1. The invitation response and participation rates were significantly higher in the TG versus the GPG (31% v’s 14%; p < 0.001, 30% v’s 14% p <0.00, respectively). H. pylori seroprevalence rates were similar between groups: 18% (11/60) in the TG, 19% (64/333) in the GPG (p<0.70). Confirmatory 13-C UBT was completed in 91% (10/11) of those who tested positive in the TG and 98% (63/64) of the GPG. Overall, ‘true’ prevalence rates based on serology & confirmatory 13-C UBT results were 10%(6/59) in the TG v’s 14% (44/325) in the GPG(p = 0.47). Treatment adherence exceeded 90% in both groups, with 100% adherence in the TG and 90% in the GPG. Among those who completed post-treatment testing (n=37), eradication was achieved in 100% of the TG (2/2) and 89% of the GPG (31/35).

Table 1 Basic Demographics by Group

	Targeted group	General population
Gender, male	97%	33%
Median age, years	31	32
Smoking status Current/previous Non-smoker	41% (24) 59% (34)	34% (137) 66% (266)
Socioeconomic status(self-rated) Higher Middle Lower Prefer not to answer	69% (40/58) 22% (13/58) 0 9% (5/58)	85% (337/397) 11% (42/397) 0% (2/397) 4% (16/397)
Family history of H.pylori infection	3% (2)	9% (36)

Conclusion

Targeted occupational screening in high-risk populations demonstrated superior response and engagement rates compared to general practice-based screening. These early results suggest this approach may be a more effective and resource-conscious strategy in low-to-intermediate risk countries and merit further evaluation in broader implementation efforts.

References

1. Teo CH, Ng CJ, Booth A, White A. Barriers and facilitators to health screening in men: A systematic review. Soc Sci Med. 2016 Sep;165:168-176. doi: 10.1016/j.socscimed.2016.07.023. Epub 2016 Aug 1. PMID: 27511617. 5.
2. Lou L, Wang L, Zhang Y, et al. Sex difference in incidence of gastric cancer: an international comparative study based on the Global Burden of Disease Study 2017.BMJ Open 2020;10:e033323. doi: 10.1136/bmjopen-2019-033323
3. Salmani H, Ahmadi M, Shahrokhi N. The Impact of Mobile Health on Cancer Screening: A Systematic Review. Cancer Informatics. 2020;19. doi:10.1177/1176935120954191
4. CSO. (2023, May 30). Employment, Occupation, Industry and Commuting - CSO -Central Statistics Office. https://www.cso.ie/en/releasesandpublications/ep/pcpsr/censusofpopulation2022- summaryresults/employmentoccupationindustryandcommuting/

Disclosure

Dr. Deane reports receipt of research funding support from EU4 Health grant GA number: 101101252. Receipt of ​13-C Urea Breath Test bags for this study was provided for by Richen - Dr Deane was the winner of the Richen Global ​Research Competition 2023

Introduction

Corpus atrophic gastritis (CAG) requires endoscopic-histological surveillance due to the risk of developing gastric neoplastic lesions (GNL). This study aimed to identify variables associated with GNL development at long-term follow-up using a feature ranking method based on a novel One-Class Support Vector Machine (SVM) model.

Aims & Methods

A dataset containing clinical, endoscopic, and histological variables from consecutive CAG patients (2001-2023) adhering to a surveillance program was considered. GNL presence at the longest available follow-up was recorded. Gastric biopsies and histological evaluations were conducted according to the updated Sydney system. CAG patients with any missing data or a GNL diagnosis at the baseline gastroscopy were excluded from the final analysis. A Fisher score-based feature ranking method and One-Class SVM were used to select the optimal subset of baseline variables associated with GNL development, aiming to achieve average sensitivity (Se) and specificity (Sp) above 80%.

Results

Overall, 355 CAG patients were initially considered. Of these, 36 were excluded due to the presence of GNL at baseline gastroscopy, and 216 for missing data. Thus, a total of 103 patients were considered and grouped into: CAG patients with [22 patients (F 68.1%), median age 68 (35-83) years] and without GNL at follow-up [81 patients (F 72.8%), median age 59(26-84) years]. After a median follow-up of 60 (12-192) months, 13 epithelial GNL (gastric adenocarcinoma or high/low-grade dysplasia) and nine type-1 gastric-neuroendocrine-tumors (T1gNET) were recorded. Parietal-cell-antibodies and pepsinogen-I < 30 μg/l were associated with both epithelial GNL and T1gNET. Antral inflammation and age > 60 were linked to epithelial GNL, while anti-thyroperoxidase-antibodies, smoking, and dyspeptic symptoms at CAG diagnosis were linked to T1gNET. Low-dose aspirin and H. pylori eradication therapy showed inverse associations with epithelial GNL and T1gNET, respectively.

Conclusion

This is the first study in which an AI model simultaneously considers clinical, endoscopic, and histological characteristics from a dataset of CAG patients, showing good sensitivity and specificity in identifying those variables associated with developing GNL. Nonetheless, we acknowledge the need for improved variable standardization and data balancing between groups to enhance model performance further.