Abstract 1010: Feasibility of serial microbiome collection in a multi-site neoadjuvant pancreatic cancer clinical trial allowing for a diverse patient population
Authors: Sherise Rogers, Ryan Thomas, Ibrahim Nassour, Ilyas Sahin, Brian Ramnaraign, Karen Russell, Steven Hughes, Kathryn Hitchcock, Omar Kayaleh, Anita Turk, Maisey Ratcliff, Thomas George
Journal: Cancer Research (2024)

Abstract Background: Pancreatic cancer portends a very poor prognosis. It is the third leading cause of cancer deaths in the United States. African Americans have a 50- 90% increased incidence of pancreatic cancer in comparison to other racial groups. 20% of patients present with operable disease and will have a median overall survival of 2.5 years if able to undergo surgical resection. There is a desperate need to discover novel ways of treating pancreatic cancer. Understanding of the microbiome may be informative to overcoming chemotherapy resistance, toxicity and improving outcomes and disparities. The aim of this study is to (1) identify changes in the microbiota during neoadjuvant treatment of pancreatic ductal adenocarcinoma that correlate with treatment response and (2) identify changes in the microbiota during neoadjuvant treatment of pancreatic ductal adenocarcinoma that correlate with treatment toxicity in a diverse patient population. Methods: Patients with resectable or borderline resectable pancreatic cancer who are enrolled in a multi-site clinical trial (NCT03483038) receiving neoadjuvant NEO-Nali-IRI (oxaliplatin, liposomal irinotecan and 5- FU) followed by surgical resection were asked to provide serial microbiome collections of saliva, urine (collected in clinic), and stool with a dietary log during the following four (or five) time points: at baseline, mid-therapy (after C4), at completion of chemotherapy (after C8), after radiation if applicable, and at 4-6 weeks post-operative. Participants were given stool collection kits during clinic visits for home sample acquisition. All stool samples were mailed to the University of Florida Health Cancer Center Microbiome Biorepository. Demographics, stage, medical history and concurrent medications including antimicrobics and probiotics, chemotherapy dose-reductions, delays, discontinuations, adverse events, safety adverse events, attribution of causality, and hospitalizations were obtained. Outcomes include imaging response using RECIST criteria, CA 19-9 trend, development of metastatic disease, and the ability to proceed to definitive surgical resection. DNA will be extracted from stool and analyzed using 16S rRNA sequencing methods to determine signatures and alpha/beta biodiversity. Descriptive statistics and correlative analysis will be reported. Continuous and categorical variables will be compared with Student’s t-test and Chi-squared test. Multiple groups will be compared by ANOVA. Kaplan-Meier logistic regression will be performed to compare outcomes between the different microbiota groupings. Conclusion: Serial microbiome collection from a multi-site clinical trial is feasible during neoadjuvant chemotherapy for pancreatic cancer and can increase the diversity of the sample population. Citation Format: Sherise Rogers, Ryan Thomas, Ibrahim Nassour, Ilyas Sahin, Brian Ramnaraign, Karen Russell, Steven Hughes, Kathryn Hitchcock, Omar Kayaleh, Anita Turk, Maisey Ratcliff, Thomas George. Feasibility of serial microbiome collection in a multi-site neoadjuvant pancreatic cancer clinical trial allowing for a diverse patient population [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1010.