Abstract A122: Assessing the prevalence of gastric cancer risk factors among carriers of germline mutations in cancer predisposition genes

Abstract Gastric cancer (GC) is a leading cause of health disparities in the country. Recent studies suggest that carriers of germline mutations in cancer predisposition genes, especially in individuals with H. pylori infection, have an increased risk of GC. This study aims to evaluate the prevalence of GC risk factors among subscribers of the Facing Hereditary Cancer Empowerment (FORCE) mailing list who carry germline mutations in cancer predisposition genes. We collected anonymized demographic and biomedical data through an online survey conducted from March to June 2025. The 23-question survey, available in English and Spanish, was self-administered via SurveyMonkey. It included questions on race, nativity, age; GC risk factors (personal and family histories of gastric and other cancers; H. pylori infection; personal history of premalignant gastroesophageal conditions). It also covered use of anti-acid medications or proton pump inhibitors and information on germline genetic variants linked to cancer predisposition. 543 respondents provided detailed complete survey response data. Descriptive association tests between GC risk factors, gastric lesions, H. pylori infection history, and hereditary germline genetic variants were conducted using Pearson’s Chi-square and Fisher’s Exact tests at a significance level of 0.05. All analyses were performed in R. Most participants were female (95%) and largely Non-Hispanic White (91%). We found a significant correlation between gastric lesions and the use of anti-acid medications or proton pump inhibitors, with daily users showing a higher prevalence of gastric lesions (44% vs. 4.2%, p0.0001). Significant associations were also found between gastric lesions and GC (7.8% vs. 3.1%, p=0.015). Notably, carriers of mutations in Lynch syndrome (LS) genes had a higher likelihood of gastric lesions (21% vs. 15% non-LS mutation gene carriers, p=0.038), while those with mutations in homologous recombination repair (HRR) genes were less likely to have gastric lesions (72% vs. 82% non-HRR gene mutation carriers, p=0.007). A higher prevalence of GC was observed in participants with H. pylori infections (15% vs. 4.8%, p=0.017). Among those diagnosed with GC, a greater proportion also had gastric lesions (73% vs. 50%, p=0.015), along with increased H. pylori infection rates (20% vs. 6.6%, p=0.017). These results suggest a significant association between H. pylori infection and an elevated risk of GC, with infection rates of 15% compared to 4.8% in the non-infected group. The findings imply that H. pylori may play a critical role in GC development, warranting further research to examine underlying mechanisms and potential preventative strategies. Citation Format: Guadalupe Carvajal MSc, C.G. C., Iñigo Verduzco Gallo MIDS, MPA, Nanci Chavarria Villa MPH, Diane Rose, Angelica Rolon MPH, April Vang MSc, Sue Friedman DVM, Luis Carvajal-Carmona Ph.D.. Assessing the prevalence of gastric cancer risk factors among carriers of germline mutations in cancer predisposition genes abstract. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr A122.