Abstract 5161: Integrating patient’s derived organoids and liquid biopsy: An exploratory study of early stage pancreatic cancer

Abstract Background: Pancreatic cancer (PC) has a 5-year survival of 12% despite recent therapeutic advancements. There is a desperate need to discover novel ways of treating PC since a large proportion of patients do not benefit from therapy and experience significant toxicity. A major cause of therapy failure is therapy resistance due to tumor heterogeneity. Nowadays, a deeper understanding of tumor heterogeneity could be assisted by the use of patients-derived organoids (PDOs). Furthermore, the use of liquid biopsy may allow for the investigation of circulating factors with predictive value and for disease monitoring over time. Methods: Patients were enrolled in the comprehensive, multiomic study of pancreatic cancer CONTAINER. Patients with early stage PC treated with preoperative chemotherapy or undergoing surgery first were selected for the present study. When possible, a surgical specimen was collected to obtain PDOs. Tissue from resected tumors was dissociated by GentleMACSTM dissociator (Miltenyi Biotec), fragments were embedded in MatrigelTMand cultured in PancreaCultTM human Organoid Media (stemcell technologies). PDO histological features were investigated by H&E staining and IHC. Blood samples were collected before and one month after surgery. From blood samples circulating tumor cells (CTCs) were enriched and isolated, extracellular vesicles (EVs) were isolated from plasma with size-exclusion chromatography and their concentration and size distribution was evaluated with NanoSight NS300. Then, EV surface antigens were characterized by flow cytometry. A panel of inflammatory cytokines was finally evaluated through Ella Automated Immunoassay System. Results: In CONTAINER study 113 patients were enrolled and 30 of them underwent surgery. 21 surgical specimens were received from which 18 PDOs were successfully established. EVs with diameter ≥ 70nm were isolated from plasma, EV mean size was similar before and after surgery whereas individual variations in particle concentration and in surface antigen exposure were observed. Correlation with clinical and pathological characteristics of patients will be performed once reached an adequate sample size for statistical analyses. A panel of inflammatory cytokines (IL1β-, IFNγ, TNFα, IL6, IL8, TGFβ1, CRP and Leptin) was assessed in plasma samples obtained before and after surgery. Except for IL1β, a significant individual variation of circulating cytokines before and after surgery was observed. Conclusions: This study will contribute to unveil mechanisms of disease progression and drug resistance in PC. Possible predictive factors and mechanisms of drug resistance will be investigated taking advantage of the information derived from both in vitro models and circulating tumor-related entities. Citation Format: Michela Cortesi, Tania Rossi, Michele Zanoni, Sara Bandini, Carlo Alberto Pacilio, Alessandro Cucchetti, Martina Valgiusti, Chiara Gallio, Alessandro Passardi, Giorgia Gurioli, Sara Bravaccini, Alessandra Dubini, Giovanni Luca Frassineti, Paola Ulivi, Giovanni Martinelli, Giorgio Ercolani, Ilario Giovanni Rapposelli. Integrating patient’s derived organoids and liquid biopsy: An exploratory study of early stage pancreatic cancer [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 5161.