Abstract 5519: Biobanking of gastric organoid models from a racially diverse cohort for gastric cancer interception
Authors: Alagesan Priya , Scotland Paula , Brown HannahSofia , McCall Shannon J. , Epplein Meira , Garman Katherine S. 
Published: June 2023

Abstract
Purpose: In the United States, significant disparities exist in gastric cancer incidence and mortality between Black Americans and non-Hispanic White Americans. Helicobacter pylori (HP) infection is the most important risk factor for developing non-cardia gastric adenocarcinoma (GAC), the most common type of gastric cancer. Non-cardia GAC is thought to occur via progression from HP-induced atrophic gastritis to gastric intestinal metaplasia (GIM), dysplasia, and cancer. The purpose of this study was to enroll racially diverse (~50% self-identified as Black) patients from the endoscopy suite across the spectrum of HP-associated disease (gastritis, GIM, GAC) in a prospective observational cohort to biobank blood and tissue samples with patient-reported survey data and clinical history from the electronic health record.
Methods: In an ongoing prospective study funded by an NIH P20 disparities project, we enrolled a diverse, racially balanced cohort of research participants undergoing upper endoscopy. We tracked and optimized screening, enrollment, and collection of blood, tissue, and survey data. Organoids were generated from fresh and/or cryopreserved biopsies of normal gastric tissue, gastritis, GIM, or GAC. Gene expression, immunohistochemistry and DNA mutational profiling were performed in a subset of organoids.
Results: To date, 563 patients were identified in screening (47% Black patients) and 250 were successfully included with a 44% enrollment rate (46% Black participants). Rates of successful sample and data collection were: 86% blood, 87% tissue collection, and 89% survey collection. The proportion of Black participants was greater in the HP-positive group (65%) vs. known HP-negative (46%) (p=0.03). Gastric organoids were generated with &gt;90% success from 49 patients, including paired organoid lines from incomplete, complete, and/or extensive GIM, matched tumor and non-tumor and gastric antrum and body samples. 20 organoid lines were derived from cryopreserved endoscopic biopsies. Ongoing characterization of tumor organoids reflects expected heterogeneity among gastric cancer patients and provides a functional measure of cytokine expression.
Conclusions: To address health disparities related to gastric cancer, diverse patient cohorts must be established with successful biobanking from groups most affected by the disease. Patient-derived gastric organoids can be generated from diverse populations and across different clinical conditions as one approach to understanding and addressing gastric cancer health disparities.
Citation Format: Priya Alagesan, Paula Scotland, HannahSofia Brown, Shannon J. McCall, Meira Epplein, Katherine S. Garman. Biobanking of gastric organoid models from a racially diverse cohort for gastric cancer interception. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5519.