Outcome In Pancreatic Ductal Adenocarcinoma Research Articles

Aronia Berry Extract Modulates MYD88/NF-kB/P-Glycoprotein Axis to Overcome Gemcitabine Resistance in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease with poor survival rates, primarily due to the limited effectiveness of gemcitabine (Gem)-based chemotherapy, as well as the acquisition of chemotherapeutic resistance. Aronia berry extracts (ABEs), abundant in phenolic constituents, have been recently recognized for their anticancer properties as well as their encouraging potential to help overcome chemoresistance in various cancers. In the present study, we explored ABE's potential to overcome Gem resistance in PDAC and identify specific growth regulatory pathways responsible for its anticancer activity. Through a series of in vitro experiments in gemcitabine-resistant (Gem-R) cells, we elucidated the synergistic interactions between Gem and ABE treatments. Using advanced transcriptomic analysis and network pharmacology, we revealed key molecular pathways linked to chemoresistance and potential therapeutic targets of ABE in Gem-R PDAC cells. Subsequently, the findings from cell culture studies were validated in patient-derived 3D tumor organoids (PDOs). The combination treatment of ABE and Gem demonstrated significant synergism and anticancer effects on cell viability, proliferation, migration, and invasion in Gem-R cells. Transcriptomic analysis revealed a correlation between the NF-Κb signaling pathway and Gem-R (p < 0.05), exhibiting a marked upregulation of MYD88. Additionally, MYD88 exhibited a significant correlation with the overall survival rates in patients with PDAC patients in the TCGA cohort (HR = 1.58, p < 0.05). The MYD88/NF-Κb pathway contributes to chemoresistance by potentially upregulating efflux transporters like P-glycoprotein (P-gp). Our findings revealed that the combined treatment with ABE suppressed the NF-Κb pathway by targeting MYD88 and reducing P-gp expression to overcome Gem resistance. Lastly, the combination therapy proved highly effective in PDOs in reducing both their number and size (p < 0.05). Our study offers previously unrecognized insights into the ability of ABE to overcome Gem resistance in PDAC cells through its targeting of the MYD88/NF-κb/P-gp axis, hence providing a safe and cost-effective adjunctive therapeutic strategy to improve treatment outcomes in PDAC.

Co‑expression of SLC20A1 and ALDH1A3 is associated with poor prognosis, and SLC20A1 is required for the survival of ALDH1‑positive pancreatic cancer stem cells.

Solute carrier family 20 member 1 (SLC20A1) is a sodium/inorganic phosphate symporter, which has been identified as a prognostic marker in several types of cancer, including pancreatic cancer. However, to the best of our knowledge, the association between SLC20A1 expression and cancer stem cell (CSC) markers, such as aldehyde dehydrogenase 1 (ALDH1), in pancreatic ductal adenocarcinoma (PDAC), and the role of SLC20A1 in PDAC CSCs remains unclear. In the present study, a genomic dataset of primary pancreatic cancer (The Cancer Genome Atlas, Pan-Cancer Atlas) was downloaded and analyzed. Kaplan-Meier analysis and multivariate Cox regression analysis were performed to evaluate the overall survival, disease-specific survival (DSS), disease-free interval (DFI) and progression-free interval (PFI). Subsequently, SLC20A1 small interfering RNA (siRNA) knockdown (KD) was induced in the PANC-1 and MIA-PaCa-2 PDAC cell lines, and in sorted high ALDH1 activity (ALDH1high) cells, after which, cell viability, in vitro tumor sphere formation, cell death and caspase-3 activity were examined. The results revealed that patients with high expression of SLC20A1 (SLC20A1 high) at tumor stage I had a poor prognosis compared with patients with low expression of SLC20A1 (SLC20A1 low) in terms of DSS, DFI and PFI. In addition, patients with high expression of SLC20A1 and ALDH1A3 (SLC20A1 high ALDH1A3 high) exhibited poorer clinical outcomes than patients with high expression of SLC20A1 and low expression of ALDH1A3 (SLC20A1 high ALDH1A3 low), low expression of SLC20A1 and high expression of ALDH1A3 (SLC20A1 low ALDH1A3 high) and SLC20A1 low ALDH1A3 low. SLC20A1 siRNA KD in ALDH1high cells isolated from PANC-1 and MIA-PaCa-2 cell lines resulted in suppression of in vitro tumorsphere formation, and enhancement of cell death and caspase-3 activity. These results suggested that SLC20A1 was involved in cell survival via the suppression of caspase-3-dependent apoptosis, and contributed to cancer progression and poor clinical outcomes in PDAC. In conclusion, SLC20A1 may be used as a prognostic marker and novel therapeutic target of ALDH1-positive pancreatic CSCs.

Genetic ancestry-associated differences in genomic profiling and treatment patterns in pancreatic ductal adenocarcinoma (PDAC).

4138 Background: Prior epidemiological studies have explored race both as a population-level risk factor and as a factor influencing outcomes in PDAC. However, the impact of genetic ancestry on PDAC remains unclear. We assessed the genomic landscape, clinical care patterns, and outcomes across ancestries in a large and diverse PDAC cohort to determine the potential impact of genomics on ancestral disparities. Methods: A total of 24,948 patients diagnosed with PDAC who received tissue-biopsy based comprehensive genomic profiling (CGP; Foundation Medicine, Inc. (FMI)) as part of routine clinical care from Aug 2014-Sep 2023 were examined for genomic differences based on genetic ancestry which was determined using a SNP-based approach. The US-based de-identified Flatiron Health (FH)-FMI clinico-genomic database (CGDB) was used to assess testing and treatment patterns based on ancestry in 3,863 patients of European (EUR) and 414 patients of African (AFR) ancestry diagnosed with PDAC. Results: The genetic ancestry distribution in the overall cohort was 80.9% EUR, 10.0% AFR, 4.9% Admixed American, 3.5% East Asian, and 0.7% South Asian. AFR patients showed a slightly younger median age at biopsy than EUR (64 vs 67, p &lt; .001). KRAS, TP53, CDKN2A/ 2B and SMAD4 were the most commonly altered genes in the cohort, as expected. Compared to EUR, AFR patients were enriched in alterations in TP53 (85% vs 78%, p &lt; .001) and KRAS (95% vs 93%, p &lt; .001). While rare, alterations in GNAS, CHEK2, and BRAF were observed less frequently in AFR (1.7% vs 3.3%, 0.3% vs 1.7%, 0.9% vs 2.2%, respectively, all p &lt; .001). In the CGDB cohort, AFR patients were likely to have lower socioeconomic status (SES) compared to EUR patients (33% of AFR in the lowest SES quintile compared to 9% of EUR; p &lt; .001 across all quintiles). AFR patients were less likely to receive care at academic centers (AFR 14.8% vs EUR 22.2%, p &lt; .001) and less likely to receive an investigational drug during their cancer treatment course (5.9% vs 14.1%, p = .001). Rates of surgery (AFR 30.2% vs EUR 34.6%, p = .08), immunotherapy (3.2% vs 3.3%, p &gt; .99), and targeted therapy (4.1% vs 6.2%, p = .28) were not significantly different. While AFR patients comprised a significantly larger proportion of AFR+EUR CGP volume following the decision to implement Medicare coverage for NGS testing (10.6% after Mar 16, 2018 vs 6.6% prior, p &lt; .001), this remained below the expected based on share of the overall US population. Conclusions: To our knowledge, this is the largest study of genetic ancestry in PDAC to date. There were largely similar patterns of gene alterations across AFR and EUR ancestry groups suggesting non-genomic factors may underlie clinical outcomes disparities which have been reported in other studies. Notably, there were ancestry-based differences associated with SES and both CGP testing and clinical trial enrollment patterns, which may impact patient outcomes.

Targeting Neoantigens in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer and is currently the third leading cause of cancer-related death in the United States after lung and colon cancer. PDAC is estimated to be the second leading cause of cancer-related death by 2030. The diagnosis at a late stage is the underlying cause for higher mortality and poor prognosis after surgery. Treatment resistance to chemotherapy and immunotherapy results in recurrence after surgery and poor prognosis. Neoantigen burden and CD8+ T-cell infiltration are associated with clinical outcomes in PDAC and paucity of neoantigen-reactive tumor-infiltrating lymphocytes may be the underlying cause for treatment resistance for immunotherapy. This suggests a need to identify additional neoantigens and therapies targeting these neoantigens to improve clinical outcomes in PDAC. In this review, we focus on describing the pathophysiology, current treatment strategies, and treatment resistance in PDAC followed by the need to target neoantigens in PDAC.

Pancreatic cancer: new approaches to drug therapy.

Outcomes in pancreatic ductal adenocarcinoma (PDAC) remain poor due to a variety of biological, clinical, and societal factors. However, in recent years, PDAC has seen 1) increased precision of initial evaluation, 2) increased emphasis on supportive care, 3) deeper understanding of the translation biology of PDAC, especially as pertains to genomic alterations, and 4) foundational combination chemotherapy clinical trials across all disease stages. These advances have led to a wide range of new approaches to drug therapy for PDAC. Currently available drugs are showing added benefit, both by resequencing them with each other and also with respect to other therapeutic modalities. Molecular strategies are being developed to predict response to known therapeutic agents and to identify others. Additionally, a wide range of new drugs for PDAC are under development, including drugs which inhibit critical molecular pathways, drugs which attempt to capitalize on homologous repair deficiencies, immunotherapeutic approaches, antimetabolic agents, and drugs which attack the extracellular matrix which supports PDAC growth. These new approaches offer the promise of improved survival for future PDAC patients.

Development of Clinical Radiomics-Based Models to Predict Survival Outcome in Pancreatic Ductal Adenocarcinoma: A Multicenter Retrospective Study.

This multicenter retrospective study aims to identify reliable clinical and radiomic features to build machine learning models that predict progression-free survival (PFS) and overall survival (OS) in pancreatic ductal adenocarcinoma (PDAC) patients. Between 2010 and 2020 pre-treatment contrast-enhanced CT scans of 287 pathology-confirmed PDAC patients from two sites of the Hopital Universitaire de Bruxelles (HUB) and from 47 hospitals within the HUB network were retrospectively analysed. Demographic, clinical, and survival data were also collected. Gross tumour volume (GTV) and non-tumoral pancreas (RPV) were semi-manually segmented and radiomics features were extracted. Patients from two HUB sites comprised the training dataset, while those from the remaining 47 hospitals of the HUB network constituted the testing dataset. A three-step method was used for feature selection. Based on the GradientBoostingSurvivalAnalysis classifier, different machine learning models were trained and tested to predict OS and PFS. Model performances were assessed using the C-index and Kaplan-Meier curves. SHAP analysis was applied to allow for post hoc interpretability. A total of 107 radiomics features were extracted from each of the GTV and RPV. Fourteen subgroups of features were selected: clinical, GTV, RPV, clinical & GTV, clinical & GTV & RPV, GTV-volume and RPV-volume both for OS and PFS. Subsequently, 14 Gradient Boosting Survival Analysis models were trained and tested. In the testing dataset, the clinical & GTV model demonstrated the highest performance for OS (C-index: 0.72) among all other models, while for PFS, the clinical model exhibited a superior performance (C-index: 0.70). An integrated approach, combining clinical and radiomics features, excels in predicting OS, whereas clinical features demonstrate strong performance in PFS prediction.

Postoperative long‑term outcomes of acute normovolemic hemodilution in pancreatic cancer: A propensity score matching analysis.

Acute normovolemic hemodilution (ANH) is a useful intraoperative blood conservation technique. However, the impact on long-term outcomes in pancreatic ductal adenocarcinoma (PDAC) remains unclear. The present study investigated the impact of ANH on long-term outcomes in patients with PDAC undergoing radical surgery. Data from 155 resectable PDAC cases were collected. Patients were categorized according to whether or not they had received intraoperative allogeneic blood transfusion (ABT) or ANH. Postoperative complications, recurrence-free survival (RFS) and disease-specific survival (DSS), before and after propensity score matching (PSM), were compared among patients who did and did not receive ANH. A total of 44 patients (28.4%) were included in the ANH group and 30 patients (19.4%) were included in the ABT group; 81 (52.3%) patients, comprising the standard management (STD) group, received neither ANH nor ABT. The ABT group had the worst prognosis among them. Before PSM, ANH was significantly associated with decreased RFS (P=0.043) and DSS (P=0.029) compared with the STD group before applying Bonferroni correction; however, no significant difference was observed after applying Bonferroni correction. Cox regression analysis identified ANH as an independent prognostic factor for RFS [relative risk (RR), 1.696; P=0.019] and DSS (RR, 1.876; P=0.009). After PSM, the ANH group exhibited less favorable RFS [median survival time (MST), 12.1 vs. 18.1 months; P=0.097] and DSS (MST, 32.1 vs. 50.5 months; P=0.097) compared with the STD group; however, these differences were not statistically significant. In conclusion, while ANH was not as harmful as ABT, it exhibited potentially more negative effects on long-term postoperative outcomes in PDAC than STD.

Abstract 6313: Enhancing CAR T cell-based immunotherapy outcomes in PDAC: Evaluating iC9.B7-H3 CAR T cells in adjuvant, neoadjuvant, and monotherapy settings

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is among the most aggressive and lethal cancers worldwide. Despite negative margin resections and subsequent systemic therapy, PDAC often recurs. Additionally, most patients present with locally advanced and unresectable tumors at the time of diagnosis. Cancer-associated fibroblasts (CAFs) contribute to the highly desmoplastic tumor microenvironment (TME) and form a biophysical barrier, limiting immune cell infiltration. Moreover, CAF-secreted factors suppress the anti-tumor activity of T cells and shift cancer cells toward invasive proliferative and mesenchymal phenotypes. Therefore, targeting CAFs can enhance T-cell infiltration and improve the efficacy of T-cell based immunotherapeutic strategies. B7-H3 is an immune checkpoint molecule highly expressed on PDAC cells and CAFs. In this study, we investigate the use of Chimeric Antigen Receptor (CAR) T cells targeting B7-H3 to eliminate metastatic PDAC in a preclinical mouse model in three different settings: I. Adjuvant II. Neoadjuvant III. CAR T cell monotherapy. Our CART-B7-H3 construct includes an inducible caspase 9 (iC9) suicide gene, which allows for the controlled elimination of the CAR T cells in the event of overwhelming cytokine release syndrome. Methods: To validate the therapeutic potential of iC9.B7-H3 CAR T cells in vivo, NSG mice were orthotopically engrafted with 1x105 patient-derived PDAC6 cells and 9x105 hCAF1 cells at a ratio of 1:9, reflecting a clinically relevant model. In the adjuvant group, mice underwent surgical resection of the primary tumor (distal pancreatectomy and splenectomy) after 25 days. On days 30 and 60, they received systemic iC9.B7-H3 CAR T cell treatment (5x106). In the neoadjuvant group, mice were systemically treated with iC9.B7-H3 CAR T cells on day 19 and underwent surgical resection of the primary tumor on day 25, following another systemic CAR T cell dose on day 60. In the CAR T monotherapy group, mice received systemic iC9.B7-H3 CAR T cells on days 19 and 60. Results: In vivo, iC9.B7-H3 CAR T cells in the neoadjuvant group effectively eradicated both local and distant PDAC metastases for the length of the experiment (180 days) and significantly increased the survival (P &amp;lt;0.0001), indicating long-term efficacy in the treatment of PDAC metastases with no adverse side effects. In the adjuvant and CAR T monotherapy groups, iC9.B7-H3 CAR T cells effectively control tumor growth, eliminate metastases, and significantly increase survival (P=0.0018 and P=0.0007, respectively). Conclusion: These data suggest that the neoadjuvant application of iC9.B7-H3 CAR T cells may demonstrate persistent efficacy in eradicating both local and distant PDAC metastases. iC9.B7-H3 CAR T cells adjuvantly and as monotherapy achieved significant tumor control. Citation Format: Shahrzad Arya, Seyed Amir Sanatkar, Marco Ventin, Giulia Cattaneo, Cristina Martin, Gabriella Lionetto, Jingyu Jia, Feng Chen, David T. Ting, Xinhui Wang, Sandra Ryeom, Cristina R. Ferrone, Soldano Ferrone. Enhancing CAR T cell-based immunotherapy outcomes in PDAC: Evaluating iC9.B7-H3 CAR T cells in adjuvant, neoadjuvant, and monotherapy settings [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 6313.

Abstract 5893: Crosstalk between sensory innervation and pancreatic ductal adenocarcinoma

Abstract In recent years, a growing body of research has illuminated the integral role of the nervous system in the initiation and progression of cancer, giving rise to the establishment of an emergent field known as cancer neuroscience. Pancreatic ductal adenocarcinoma (PDAC), constituting 90% of pancreatic cancers, manifests as a highly malignant solid tumor characterized by insidious onset, strong invasiveness, and a notable propensity for recurrence or metastasis. Consequently, the 5-year survival rate for PDAC remained dismally low at approximately 10% in 2021. Notably, PDAC is distinguished by perineural invasion (PNI), a phenomenon linked to postoperative recurrence and metastasis. A thorough exploration of the interplay between peripheral innervation and PDAC holds promise for identifying novel targets and therapies to enhance outcomes in PDAC. This study unveils a correlation between PDAC patients exhibiting high calcitonin gene-related peptide-positive (CGRP+) sensory innervation in the tumor microenvironment (TME) and diminished overall survival (OS) and disease-free survival (DFS) compared to those with lower CGRP+ nociceptive innervation. Concurrently, heightened CGRP+ sensory innervation corresponds to increased cancer pain, as assessed by Visual Analog Scale (VAS) scores. Further analysis reveals a negative association between CGRP+ nociceptive nerves and lymphatic metastasis, as well as tumor size in PDAC patients. In a murine PDAC model, the genetic or chemical ablation of CGRP+ sensory neurons significantly impedes disease progression. Additionally, sensory neuron ablation attenuates cancer-induced vesical pain and enhances the locomotor function of mice, suggesting an improvement in overall quality of life. Mechanically, within the TME of PDAC, the secretion of neuropeptides substance P (SP) and CGRP from sensory neurons is elevated, with CGRP exhibiting a more pronounced increase. Furthermore, the expression of the CGRP receptor—receptor activity modifying protein 1 (RAMP1)—surpasses that of the SP receptor in the TME. Subsequent blockade of the CGRP pathway using the RAMP1 antagonist Rimegepant significantly suppresses PDAC progression and alleviates cancer pain, accompanied by improved locomotor function. In summary, sensory innervation actively participates in the progression of PDAC through the secretion of CGRP. Consequently, the inhibition of the CGRP pathway emerges as a potential therapeutic strategy for both PDAC and cancer-induced pain. Citation Format: Kaiyuan Wang, Bo Ni, Xiuchao Wang, Jihui Hao. Crosstalk between sensory innervation and pancreatic ductal adenocarcinoma [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 5893.

Abstract 7615: Epithelial-mesenchymal-transition gene signature changes and poor oncological outcome in Candida-positive pancreatic ductal adenocarcinoma

Abstract Candida are commonly found in bile collected during surgery in pancreatic ductal adenocarcinoma (PDAC) patients. However, their significance in tumor biology and oncological outcome is unclear. PDAC patients receiving neoadjuvant therapy and pancreatectomy with intraoperative bile fungal culture were identified (N=40) in a prospective single-institution cohort. Tumor regression scores (TRS) were abstracted from pathology reports and correlated with bile fungal cultures. Bulk tumor RNASeq data were obtained from the Oncology Research Information Exchange Network (ORIEN). Tumor microbiome data of non-metastatic PDAC patients with upfront surgery were extracted using the {exotic} tool (Hoyd et al. Cancer Res. Commun., 2023). Gene expression profiles were compared between Candida+ and Candida- tumors, defined by a cutoff microbial count of 0. Overall survival (OS) of resected PDAC patients with Candida+ and Candida- tumors was compared using Kaplan Meier survival analysis. From the single-institution PDAC cohort, Candida+ bile was associated with poor pathological response to neoadjuvant therapy (Table 1). Using the ORIEN cohort, Candida were detected in 67% (106/158) of the PDAC tumors. Patients with Candida+ tumors had worse OS (median 28 vs. 56 months, Log-Rank p&amp;lt;0.008). Gene Set Enrichment Analysis (GSEA) using Hallmark gene sets showed an enrichment of epithelial-mesenchymal-transition (EMT) gene set and a reduction of metabolic and DNA repair gene sets in Candida+ tumors. GSEA for Immune signature and Tumor Immune Microenvironment Deconvolution (TIMEx) cell types showed an enrichment of Stromal-Fibroblast and EMT signature in Candida+ tumors. Further investigations are underway to determine the causal and metabolic relationship between Candida and this tumor microenvironment with EMT and stromal fibroblasts which is a well-known contributor to poor chemotherapy response and oncological outcome of PDAC. Table 1: Pathological Response to Neoadjuvant Therapy for PDAC Bile Culture TRS0/1 TRS2 TRS3 Candida - 5 (25%) 15 (75%) 0 (0%) Candida + 1 (5%) 11 (55%) 8 (40%) TRS: Tumor Regression Score (TRS0: complete response; TRS1: near-complete response; TRS2: partial response; TRS3: no response). Chi-Square Test, P=0.0035. Citation Format: Po Hien Ear, Min Hu, Jonathan S. Shilyansky, Naomi H. Fei, Sam Coleman, Rebecca Hoyd, Caroline E. Wheeler, Kelsey L. Steckly, Michelle L. Churchman, Nicholas Denko, Rebecca D. Dodd, Sheetal Hardikar, Ning Jin, Qin Ma, Martin D. McCarter, Abdul Rafeh Naqash, Afaf E. Osman, Gregory Riedlinger, Lary A. Robinson, Bryan P. Schneider, Eric A. Singer, Ahmad A. Tarhini, Gabriel Tinoco, Cornelia M. Ulrich, Yousef Zakharia, Daniel Spakowicz, Aik Choon Tan, Carlos H. Chan. Epithelial-mesenchymal-transition gene signature changes and poor oncological outcome in Candida-positive pancreatic ductal adenocarcinoma [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 7615.

Circulating tumor-associated antigen-specific IFNγ+4-1BB+ CD8+ T cells as peripheral biomarkers of treatment outcomes in patients with pancreatic cancer.

CD8+ T cells affect the outcomes of pancreatic ductal adenocarcinoma (PDAC). Using tissue samples at pre-treatment to monitor the immune response is challenging, while blood samples are beneficial in overcoming this limitation. In this study, we measured peripheral antigen-specific CD8+ T cell responses against four different tumor-associated antigens (TAAs) in PDAC using flow cytometry and investigated their relationships with clinical features. We analyzed the optimal timing within the treatment course for effective immune checkpoint inhibition in vitro. We demonstrated that the frequency of TAA-specific IFNγ+4-1BB+ CD8+ T cells was correlated with a fold reduction in CA19-9 before and after neoadjuvant therapy. Moreover, patients with TAA-specific IFNγ+4-1BB+ CD8+ T cells after surgery exhibited a significantly improved disease-free survival. Anti-PD-1 treatment in vitro increased the frequency of TAA-specific IFNγ+4-1BB+ CD8+ T cells before neoadjuvant therapy in patients, suggesting the importance of the timing of anti-PD-1 inhibition during the treatment regimen. Our results indicate that peripheral immunophenotyping, combined with highly sensitive identification of TAA-specific responses in vitro as well as detailed CD8+ T cell subset profiling via ex vivo analysis, may serve as peripheral biomarkers to predict treatment outcomes and therapeutic efficacy of immunotherapy plus neoadjuvant chemotherapy.

Association of Mutant KRAS Alleles With Morphology and Clinical Outcomes in Pancreatic Ductal Adenocarcinoma.

Mutant KRAS is the main oncogenic driver in pancreatic ductal adenocarcinomas (PDACs). However, the clinical and phenotypic implications of harboring different mutant KRAS alleles remain poorly understood. To characterize the potential morphologic and clinical outcome differences in PDACs harboring distinct mutant KRAS alleles. Cohort 1 consisted of 127 primary conventional PDACs with no neoadjuvant therapy, excluding colloid/mucinous, adenosquamous, undifferentiated, and intraductal papillary mucinous neoplasm-associated carcinomas, for which an in-house 42-gene mutational panel had been performed. A morphologic classification system was devised wherein each tumor was assigned as conventional, papillary/large duct (P+LD, defined as neoplastic glands with papillary structure and/or with length ≥0.5 mm), or poorly differentiated (when the aforementioned component was 60% or more of the tumor). Cohort 2 was a cohort of 88 PDACs in The Cancer Genome Atlas, which were similarly analyzed. In both cohorts, there was significant enrichment of P+LD morphology in PDACs with KRAS G12V and G12R compared with G12D. In the entire combined cohort, Kaplan-Meier analyses showed longer overall survival (OS) with KRAS G12R as compared with G12D (median OS of 1255 versus 682 days, P = .03) and in patients whose PDACs displayed P+LD morphology as compared with conventional morphology (median OS of 1175 versus 684 days, P = .04). In the adjuvant-only subset, KRAS G12R had the longest OS compared with G12D, G12V, and other alleles (median OS unreached/undefined versus 1009, 1129, and 1222 days, respectively). PDACs with different mutant KRAS alleles are associated with distinct morphologies and clinical outcomes, with KRAS G12R allele associated with P+LD morphology and longer OS when compared with G12D using Kaplan-Meier studies.

Impact of KRAS mutations and co-mutations on clinical outcomes in pancreatic ductal adenocarcinoma

The relevance of KRAS mutation alleles to clinical outcome remains inconclusive in pancreatic adenocarcinoma (PDAC). We conducted a retrospective study of 803 patients with PDAC (42% with metastatic disease) at MD Anderson Cancer Center. Overall survival (OS) analysis demonstrated that KRAS mutation status and subtypes were prognostic (p < 0.001). Relative to patients with KRAS wildtype tumors (median OS 38 months), patients with KRASG12R had a similar OS (median 34 months), while patients with KRASQ61 and KRASG12D mutated tumors had shorter OS (median 20 months [HR: 1.9, 95% CI 1.2–3.0, p = 0.006] and 22 months [HR: 1.7, 95% CI 1.3–2.3, p < 0.001], respectively). There was enrichment of KRASG12D mutation in metastatic tumors (34% vs 24%, OR: 1.7, 95% CI 1.2–2.4, p = 0.001) and enrichment of KRASG12R in well and moderately differentiated tumors (14% vs 9%, OR: 1.7, 95% CI 1.05–2.99, p = 0.04). Similar findings were observed in the external validation cohort (PanCAN’s Know Your Tumor® dataset, n = 408).

The Role of Chemokines in Orchestrating the Immune Response to Pancreatic Ductal Adenocarcinoma

Chemokines are small molecules that function as chemotactic factors which regulate the migration, infiltration, and accumulation of immune cells. Here, we comprehensively assess the structural and functional role of chemokines, examine the effects of chemokines that are present in the pancreatic ductal adenocarcinoma (PDAC) tumor microenvironment (TME), specifically those produced by cancer cells and stromal components, and evaluate their impact on immune cell trafficking, both in promoting and suppressing anti-tumor responses. We further explore the impact of chemokines on patient outcomes in PDAC and their role in the context of immunotherapy treatments, and review clinical trials that have targeted chemokine receptors and ligands in the treatment of PDAC. Lastly, we highlight potential strategies that can be utilized to harness chemokines in order to increase cytotoxic immune cell infiltration and the anti-tumor effects of immunotherapy.

The Molecular Twin artificial-intelligence platform integrates multi-omic data to predict outcomes for pancreatic adenocarcinoma patients.

Contemporary analyses focused on a limited number of clinical and molecular biomarkers have been unable to accurately predict clinical outcomes in pancreatic ductal adenocarcinoma. Here we describe a precision medicine platform known as the Molecular Twin consisting of advanced machine-learning models and use it to analyze a dataset of 6,363 clinical and multi-omic molecular features from patients with resected pancreatic ductal adenocarcinoma to accurately predict disease survival (DS). We show that a full multi-omic model predicts DS with the highest accuracy and that plasma protein is the top single-omic predictor of DS. A parsimonious model learning only 589 multi-omic features demonstrated similar predictive performance as the full multi-omic model. Our platform enables discovery of parsimonious biomarker panels and performance assessment of outcome prediction models learning from resource-intensive panels. This approach has considerable potential to impact clinical care and democratize precision cancer medicine worldwide.

Intratumoral Cell Neighborhoods Coordinate Outcomes in Pancreatic Ductal Adenocarcinoma

Background and AimsPancreatic ductal adenocarcinoma (PDA) is a highly lethal disease characterized by a spatially heterogenous tumor microenvironment (TME). Within the PDA microenvironment, cells organize into communities where cell fate is influenced by neighboring cells of diverse ontogeny and function. However, it remains unclear how cell neighborhoods in the TME evolve with treatment and impact clinical outcomes. MethodsHere, using automated chromogenic multiplex immunohistochemistry (mIHC) and unsupervised computational image analysis of human PDA tumors, we investigated cell neighborhoods in surgically resected tumors from patients with chemotherapy-naïve PDA (n = 59) and neoadjuvant chemotherapy-treated PDA (n = 57). Single cells were defined by lineage markers (CD3, CD8, Foxp3, CD68, CK19), proliferation (Ki67) and neighboring cells. ResultsDistinct intra-tumoral immune and tumor cell subsets defined by neighboring cells. Higher content of stromal-associated macrophages was seen in chemotherapy-naive tumors from long-term survivors (LTS, OS > 3 years) compared to short-term survivors (STS, OS < 1 year), whereas immune-excluded tumor cells were higher in STS. Chemotherapy-treated versus -naïve tumors showed lower content of tumor-associated T cells and macrophages but similar densities of stromal-associated immune cells. However, proliferating tumor cell subsets with immune rich neighborhoods were higher in chemotherapy-treated tumors. In a blinded analysis of tumors from patients treated with neoadjuvant chemotherapy, a composite index comprising lower quantities of immune-excluded tumor cells and higher spatially distinct immune cell subsets associated with prolonged survival. Conclusions: Together, these data provide new insights into discrete cell communities in PDA and show their clinical relevance.

Abstract C098: Impact of KRAS mutations and co-mutations on clinical outcomes in pancreatic ductal adenocarcinoma

Abstract Background KRAS is the most frequently mutated gene in pancreatic ductal adenocarcinoma (PDAC). Over the past decade, targeting KRAS has emerged as a promising approach for PDAC treatment. However, the associations between KRAS mutations status and comutation landscape with clinical outcomes remain understudied. We investigated the impact of KRAS mutant allelic status and genomic co-mutations with clinical outcomes. Methods 803 patients with PDAC who underwent CLIA somatic tumor mutation testing at MD Anderson Cancer Center (MDACC) from 1997 to 2023 were identified after an IRB approval. Tumor genomic alterations, demographics, clinical, molecular, and pathological data were extracted from electronic medical records and tumor registry through the Palantir Foundry platform. An external cohort from PanCAN’s Know Your Tumor® dataset with 408 patients served as the validation cohort. Overall Survival (OS) was calculated from the date of initial diagnosis to death or last follow-up. Pearson’s chi-squared tests (or Fisher’s exact tests) were used to determine the association between groups. The Kaplan-Meier method was used to estimate the median OS. Results 703 patients had KRAS gene included in the mutation testing at MDACC from 1997 to 2023. KRAS was the top mutated gene (82%), followed by TP53 (69%), then CDKN2A (20%). In KRAS mutant patients, G12D was the most common variant (39%), followed by G12V (31%), then G12R (14%), and Q61 (6%). In patients tested with multi-gene panels, a co-mutation analysis revealed that the most common co-occurring mutations with KRAS mutation was TP53 (75%), followed by CDKN2A (22%), SMAD4 (14%) and ARID1A (10%). The median follow-up was 41 months and median OS was 19 months in the overall population. KRAS mutation status and subtypes was prognostic of OS (p&amp;lt;0.001). Patients with KRAS wildtype had median OS of 38 months and KRASG12R had median OS of 34 months (HR:1.0, 95% CI 0.71-1.5, p=0.88), while patients with KRASQ61 had worst median OS of 20 months (HR: 1.9, 95% CI 1.2-3.0, p=0.006) and KRASG12D had median OS of 22 months (HR: 1.7, 95% CI 1.3-2.3, p&amp;lt;0.001). Similar findings were observed in patients with stage IV disease (n=302), KRASG12D remained associated with significantly worse OS (HR= 1.7, 95% CI 1.1-2.6, p=0.009). There was a significant enrichment of KRASG12D mutation in metastatic disease compared to localized disease (stage I-III) (OR: 1.7, 95% CI 1.2-2.4, p=0.001) and enrichment of KRASG12R mutation in well and moderately differentiated tumors versus poorly differentiated tumors (OR: 1.7, 95% CI 1.05-2.99, p=0.04). In the external cohort (PanCAN’s Know Your Tumor® dataset), similar findings were observed. KRASG12R was associated with longer median OS (32 months), while KRASQ61 (16 months, HR: 2.6, 95% CI 0.88-7.8, p=0.02) and KRASG12D (23 months, HR: 1.68, 95% CI 1.06-2.65, p=0.04) were associated with significantly worse median OS. Conclusion Allele specific associations of KRAS mutation with clinical outcomes were identified in PDAC. We found better OS with G12R and worse OS with G12D and Q61. Citation Format: Abdelrahman Yousef, Mahmoud Yousef, Saikat Chowdhury, Kawther Abdilleh, Mark Knafl, Paul Edelkamp, Kristin Alfaro-Munoz, Ray Chacko, Jennifer Peterson, Brandon Smaglo, Robert Wolff, Shubham Pant, Michael Lee, Jason Willis, Michael Overman, Sudheer Doss, Lynn Matrisian, Mark Hurd, Rebecca Snyder, Matthew Katz, Huamin Wang, Anirban Maitra, John Paul Shen, Dan Zhao. Impact of KRAS mutations and co-mutations on clinical outcomes in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C098.

Abstract C113: The mitochondrial calcium uniporter supports epithelial to mesenchymal transition of pancreatic ductal adenocarcinoma

Abstract In spite of many new developments in cancer treatments and targeted therapies over the past few decades, outcomes for pancreatic ductal adenocarcinoma (PDAC) patients continue to be poor. Calcium signaling and mitochondrial function are known to contribute to cancer outcomes in many paradigms, yet much remains unknown in the context of PDAC. The mitochondrial Ca2+ uniporter, MCU, is the main route by which mitochondria can take up Ca2+ into the mitochondrial matrix, where it drives metabolic activity in the tricarboxylic acid cycle and promotes ATP synthesis by the electron transport chain. Our previous work suggests that Ca2+ flux from the endoplasmic reticulum (ER) into the mitochondria at mitochondria-associated membranes (MAMs) may be important to drive malignancy. Here, we show that MCU expression is associated with poor outcomes in PDAC patients and disease progression in murine organoid models of cancer development. Further, deletion of Mcu in murine KPC cells results in ablation of mitochondrial Ca2+ uptake, which reduces growth, proliferation, and clonogenicity. Tumor growth and metastatic colonization are also reduced in orthotopic implantation models, with some KPCY-McucKO models failing to develop primary lesions. This suggests that MCU, and thus mitochondrial Ca2+, play an important role in tumor growth. Critically, we here elucidate a heretofore unknown relationship between ER-to-mitochondrial Ca2+ flux through Mcu and epithelial to mesenchymal transition (EMT), an important process that contributes to poor outcomes in PDAC. To this end, McucKO associates with reduced basal Snail expression and reduced TGFβ secretion, and McucKO clones have a more epithelial morphology than their isogenic, Mcu-expressing counterparts. Both stable expression of Snail and treatment with TGFβ are able to rescue growth, mobility, and clonogenic deficits in McucKO cell lines to levels comparable to isogenic, Mcu-expressing cell lines. Uptake assays, metabolomics, isotope tracing, and mRNA-Seq have enabled us to elucidate metabolic and transcriptional rewiring induced by Snail and TGFβ treatment which may promote cell survival and proliferation despite the lack of Mcu. This work has important implications for potential targeting of Ca2+ signaling in the context of PDAC. Citation Format: Jillian S. Weissenrieder, Jason Pitarresi, Natalie Weinmann, Rebecca Drager, Usha Paudel, Anil Rustgi, Ben Stanger, J. Kevin Foskett. The mitochondrial calcium uniporter supports epithelial to mesenchymal transition of pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C113.

Abstract C060: Characterization of a collection of patient-derived xenograft models for pancreatic ductal adenocarcinoma translational research

Abstract To conduct successful translational research for pancreatic ductal adenocarcinoma (PDAC), it is imperative to have preclinical models that accurately reflect the intricate molecular, genomic, and histological features of the disease. Patient-derived xenografts (PDXs) have emerged as invaluable platforms for studying tumor biology and personalized therapeutic intervention. Here we present a collection of 32 PDAC PDX models established and fully characterized in our institution. This PDAC PDX collection was generated with tissue from both primary and metastatic lesions, comprehensively representing the disease spectrum. Genomic profiling using next-generation sequencing revealed a remarkable concordance between the PDX samples and their original patient tumor tissue. Notably, identifying common driver mutations associated with PDAC further validates the clinical relevance of this PDX collection. Moreover, histopathologic examination confirmed the similarity between PDX tumor samples and their original patient tissue samples. Interestingly, we also optimized a protocol to generate tumoroids from PDAC PDXs. Leveraging the broad spectrum of disease represented in our collection will facilitate addressing critical research questions, identifying novel therapeutic targets, and ultimately improving patient outcomes of PDAC. Citation Format: Mariana Yáñez, Enrique Javier Arenas, Teresa Macarulla, Tian Tian, Joaquín Arribas, Sofía Llorente, Carles Fabregat, Marta Escorihuela, Florian Castet, Jessica Querol, Maria Teresa Salcedo. Characterization of a collection of patient-derived xenograft models for pancreatic ductal adenocarcinoma translational research [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C060.

Longitudinal monitoring of exosome associated KRAS mutations predicts oncological outcomes in pancreatic ductal adenocarcinoma

Longitudinal monitoring of exosome associated KRAS mutations predicts oncological outcomes in pancreatic ductal adenocarcinoma