Abstract PO-183: Racial disparities in Helicobacter pylori infection: A systematic review and retrospective study

Abstract

Abstract Background/Aims: Racial disparities exist across the spectrum of non-cardia gastric carcinogenesis, from H. pylori infection through gastric intestinal metaplasia and gastric cancer. Currently, there are no guidelines supporting widespread gastric cancer screening in the US, however there are suggestions that race and ethnicity may be important risk factors for both H. pylori infection and gastric cancer. A better understanding of racial differences in H. pylori infection prevalence and virulence might allow for improved risk stratification strategies for gastric cancer prevention. This systematic review sought to provide a comprehensive evaluation of the literature regarding racial disparities in H. pylori infection in the US. The review was performed to inform a larger translational research project at Duke that includes a retrospective study of Duke's patient population with H. pylori infection and gastric intestinal metaplasia. Methods: We performed a systematic search of Medline, EMBASE, and Web of Science through May 26, 2021. Using COVIDENCE software, 4143 studies were imported for screening, and 39 relevant studies that reported H. pylori infection prevalence by race in the US were identified. Odds ratios and prevalence of H. pylori for individual studies were compiled and assessed. We also present here an initial comparison of characteristics by race in a new, large retrospective study of H. pylori and intestinal metaplasia cases diagnosed from upper endoscopy from 2015-2019 at Duke University Hospitals. Results: All studies included documented higher H. pylori infection prevalence in Blacks and Hispanics compared to whites in the US. The ratio of Black to white H. pylori infection prevalence ranged from 1.3 to 5.4; for Hispanic to white H. pylori infection, the prevalence ranged from 1.8 to 4.4. Ten studies included odds ratios or risk ratios in their analysis. Compared to whites, Blacks had 2.6-4.4 times greater odds and Hispanics a 1.8-3.9 times greater odds of having an H. pylori infection. Four studies included prevalence of seropositivity to the H. pylori virulence factors VacA and CagA by race. In three of the four studies, Blacks and Hispanics had higher prevalence rates of infection with both VacA and CagA positive strains. In our local retrospective chart review, among all patients undergoing endoscopic biopsies at Duke in a 5-year period (n=20,352), H. pylori and H. pylori-positive intestinal metaplasia were 4-5 times more common in Blacks compared to whites. Conclusion: In a systematic review, across all identified studies and all time points, Blacks and Hispanics had significantly higher prevalence rates of H. pylori infection compared to whites in the US. This increased prevalence of H. pylori and H. pylori virulence factors may be relevant in the clinical setting relating to H. pylori testing and gastric cancer prevention. Similarly, in our local Duke cohort, a significantly greater percentage of Blacks presented with H. pylori positivity than whites at upper endoscopy. Citation Format: HannahSofia T. Brown, Meira Epplein, Helen Tang, Katherine Garman. Racial disparities in Helicobacter pylori infection: A systematic review and retrospective study [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-183.